University Chemistry

Special Subject

An improved experiment for measuring colloidal particle sizes
Shengyuan Zhong, Jing Zhong, Yuyao Zhou, Lifeng Ruan, Weitai Wu, Bin Ren
This study presents an enhanced approach to the colloidal particle size measurement experiment in undergraduate physical chemistry laboratories. Conventional teaching methods predominantly utilize commercial particle-size analyzers, which often yield fluctuating results while operating as “black-box” systems. This opacity prevents students from discerning whether variations originate from instrumental noise or operational errors, nor does it clarify how single fixed-angle measurements can be influenced by multiple factors. To address these limitations, we developed an open-architecture particle-sizing instrument and integrated its assembly process into the curriculum. This hands-on approach enables students to comprehend both the acquisition of raw optical signals and methods for enhancing measurement precision. Additionally, we created dedicated teaching software to visualize abstract concepts, guiding students through the complete particle size calculation workflow. By implementing this hardware-software collaborative teaching model, students gain practical experience spanning from raw signal acquisition to final data analysis, thereby eliminating uncertainties about measurement variability while deepening their understanding of measurement principles and data reliability.
2026, 41 (5): 1-13. DOI: 10.12461/PKU.DXHX202511149

Molecular shield: decoding the chemistry principles of UV protection
Changjia Hu, Sinuo Li, Wen Jiang, Ruiyang Wu, Wenhong Ruan, Rong Lai
Sunlight’s ultraviolet (UV) radiation presents a double-edged phenomenon. While moderate exposure confers notable benefits, excessive UV exposure can induce skin damage and potentially lead to carcinogenesis. Sunscreen agents function as customized “molecular shields” for the skin, utilizing their distinctive physicochemical properties to establish a robust defensive barrier against UV radiation. This study systematically investigates the underlying chemical mechanisms of UV protection through comprehensive performance evaluations of both laboratory-formulated sunscreen emulsions and commercial products. Employing UV spectrophotometry, UV power meter, and UV indicating card across multiple assessment dimensions, we demonstrate the variations among different sunscreen agents and sun protection factor (SPF) values, successfully correlating protective efficacy with active components. This work further innovatively develops engaging experiments including UV visualization and hands-on sunscreen formulation, effectively translating complex photoprotection principles into accessible science popularization practices. This approach establishes a complete public education framework spanning from fundamental knowledge to practical protection strategies, seamlessly integrating UV protection awareness into daily life. Our work fosters scientific understanding of “photoprotection for photohealth”, enabling the public to safely enjoy sunlight while appreciating chemistry's remarkable contributions to modern living.
2026, 41 (5): 14-25. DOI: 10.12461/PKU.DXHX202510001

Gorgeous metamorphosis of konjac: unveiling the hydrogel formation mechanism from ingredients to facial cleansing puff
Xiang Li, Lei Tan, Keran Ding, Faqiong Zhao, Linbo Gong
Building upon the principle of alkali-induced gelation of konjac glucomannan (KGM), this study designed and implemented a chemistry outreach experiment involving the preparation of konjac-based facial cleansing puffs. The experiment innovatively combines natural polymer hydrogels, green household chemistry, and home-based experimentation using food-grade materials, enabling participants to create environmentally friendly and practical cleansing products. Tailored to diverse audiences, the outreach program features a multi-level interactive approach incorporating instructional videos, science manuals, narrative explanations, hands-on activities, and extension experiments. This comprehensive design successfully achieves three key outreach objectives: ensuring safety and operability, demonstrating underlying principles, and delivering practical outcomes. The experiment vividly illustrates both the fascination and utility of chemistry, facilitating the integration of polymer science into daily life while enhancing public scientific literacy.
2026, 41 (5): 26-35. DOI: 10.12461/PKU.DXHX202509139

Digital and intelligent improvement of the synthesis and property investigation of iron complexes: an innovative approach to determining the composition and stability constant of the sulfosalicylic acid-iron complex in undergraduate chemistry experiment
Sihan Wang, Chenxi Yu, Shuzhang Ran, Jiawei Chen, Shoutong Rao, Xinyi Liang, Ruiqi Dong, Guixiang Zeng, Guoqiang Wang, Jing Ma
This study addresses several technical limitations in the “Basic Chemistry Experiment” involving the determination of iron(III) sulfosalicylate complex, including background absorbance interference, inability to identify coordination ratios (n) in unknown systems, and low experimental throughput (measuring only one ligand per experiment). Methodologically, we developed a system of equations incorporating absorbance data from all components, effectively eliminating background interference and increasing ligand measurement capacity from 1 to 11 per experiment. Analytically, we implemented machine learning algorithms to construct a stability constant prediction model, facilitating determination of coordination ratios (n). The model was validated using UV-Vis spectral data, with feature importance analysis revealing key coordination factors, thereby providing empirical support for coordination field theory instruction. Pedagogically, we established an intelligent teaching platform to reduce technical barriers in digital implementation, promoting wider adoption of these improved methods. The enhanced protocol maintains analytical precision while significantly improving throughput and applicability. This inquiry-based approach effectively develops students’ data analysis skills and problem-solving capabilities for complex chemical challenges.
2026, 41 (5): 36-49. DOI: 10.12461/PKU.DXHX202511137

Exploring complicated structure and reactivity of Grignard reagents via their reactions with styrene oxide
Haoqi Zhang, Borui Yao, Yun Zhang, Zhiguang Song, Bo Wang
The preparation and reactions of Grignard reagents constitute fundamental experiments in organic chemistry laboratory courses. However, the conventional experiment involving the preparation of n-butyl Grignard reagent from 1-bromobutane and magnesium turnings, followed by its addition to acetone to yield 2-methylhexan-2-ol, fails to demonstrate the compositional and structural complexity of Grignard reagents and their impact on reactivity. In this study, we present a modified experimental design using existing materials, where student groups prepare n-butyl Grignard reagents in different ethereal solvents. These reagents, along with di(n-butyl)magnesium, are then reacted with styrene oxide to produce distinct products. Students analyze the resulting products through ¹H-nuclear magnetic resonance (¹H-NMR) spectroscopy and comparison with reference standards to determine product structures and distributions. By examining these experimental results and studying the Schlenk equilibrium through self-directed learning, students gain insights into the compositional complexity of Grignard reagents and the significant influence of Lewis acidic MgX₂ on their reactivity due to the Schlenk equilibrium. This research-oriented modification not only reinforces fundamental skills in air- and moisture-free synthesis but also enhances students’ abilities in molecular structure analysis and experimental methodology, thereby stimulating their scientific curiosity and fostering innovative thinking.
2026, 41 (5): 50-61. DOI: 10.12461/PKU.DXHX202511129

Preparation and fluorescence properties of lanthanide Eu-metal-organic frameworks based on microfluidics
Yue Dai, Yiwen Wang, Yu Wang, Mingxuan Liang, Yan Su
To address the limitations of conventional chemistry experiment teaching, particularly the lack of frontier scientific integration and low comprehensiveness in experimental content, this study designed an innovative comprehensive experiment focusing on the microfluidic synthesis of lanthanide Eu-metal-organic frameworks (Eu-MOFs) and their fluorescence sensing properties. The experiment employed advanced microfluidic technology for the controlled preparation of Eu-MOFs microspheres, followed by systematic characterization using X-ray diffraction (XRD), inverted microscopy, and fluorescence spectroscopy to investigate their Fe³⁺ sensing capabilities. Comparative results demonstrated that the microfluidically synthesized Eu-MOFs exhibited superior morphological homogeneity and lower detection limits than those prepared by traditional methods, indicating promising potential for metal ion sensing applications. This experiment established a complete training system encompassing “synthesis-characterization-analysis-application” processes, incorporating advanced instrumentation such as fluorescence spectrometers and inverted microscopes. The approach not only enhances students’ mastery of microfluidic technology but also deepens their understanding of coordination chemistry principles and fluorescence sensing mechanisms. This work provides valuable insights for reforming chemical experiment pedagogy and cultivating innovative talents.
2026, 41 (5): 62-69. DOI: 10.12461/PKU.DXHX202510029

Synthesis of an aggregation-induced emission fluorescent probe and its application in fingerprint development: exploration of a comprehensive chemistry experiment for undergraduates
Yubin Su, Chenyu Yao, Shuyan Chen, Lisha Xu, Min Peng, Yawen Wang, Yu Peng, Jianfeng Zheng
Aggregation-induced emission (AIE) materials represent a cutting-edge system in fluorescence sensing and bioimaging. Introducing these materials into undergraduate laboratory courses holds significant pedagogical value for cultivating innovative chemistry talents. This experiment designed and synthesized an AIE fluorescent probe (TPE-Th-1-OH) based on a tetraphenylethylene (TPE) framework. The target molecule was selected through density functional theory (DFT) calculations and synthesized via Knoevenagel condensation. Structural confirmation was achieved through Proton Nuclear Magnetic Resonance spectroscopy and melting point determination, systematically training students in computational chemistry, organic synthesis, and structural characterization. Photophysical studies demonstrated the probe’s excellent fluorescence stability across a wide pH range (3.0–10.0), with intensity variations below 10%. When applied for fingerprint visualization on various substrates (cardboard, basswood, alumina ceramic, acrylic plate, cover glass, and aluminum foil), the probe exhibited high resolution and strong anti-interference capabilities against complex backgrounds. This experiment effectively integrates AIE research with undergraduate teaching, encompassing four key modules: computational chemistry, organic synthesis, spectral characterization, and practical applications. The established “theory-synthesis-characterization-application” integrated teaching system significantly enhances senior undergraduates’ comprehensive analytical skills and research innovation capabilities.
2026, 41 (5): 70-78. DOI: 10.12461/PKU.DXHX202511031

Amber-yellow alkali-infused glutinous rice: a fascinating exploration of the chemical magic behind the aroma of zongzi
Yuyu Chen, Zechun Cai, Lijie Chen, Linkai Huang, Yuxiu Li, Wenhong Ruan
Alkaline zongzi, a traditional delicacy prepared by steeping glutinous rice in plant ash extract, characteristically exhibits a golden-yellow or light brown hue with distinctive textural resilience. This study adopts “Chemical Principles in Gastronomy” as its conceptual framework, replicating the traditional zongzi-making process by formulating an alkaline solution from Vitex negundo branch ashes (pH ≈ 9). Parallel experiments were conducted using isohydric potassium carbonate solutions (termed “alkaline water”) and pure water controls. Through visualized reaction processes and instrumental analyses, we systematically investigated the chemical interactions between alkaline solutions and glutinous rice components (polyphenols and proteins), elucidating the fundamental relationships between culinary processing and chemical transformations. The experimental design incorporated multiple modules: pH characterization of plant ash extracts, comparative chromatic analysis of treated glutinous rice versus starch, and mechanical property evaluation of alkali-heated glutinous rice dough. Our science communication strategy integrates hands-on workshops, live demonstrations, thematic lectures, and innovative experiments, offering tiered educational content adaptable for diverse audiences. This initiative seeks to cultivate public engagement with chemistry, advocate nutritional awareness, and celebrate the chemical wisdom embedded in Chinese culinary heritage.
2026, 41 (5): 79-90. DOI: 10.12461/PKU.DXHX202511145

Improved experiment of potassium ferricyanide electrochemical reaction process analysis based on a new method of rotating electrode dual channel
Yawei Li, Siming Li, Fuhao Duan, Xuran Wang, Yangyang Zhao, Yue Zhang, Wei Guo, Junsheng Hao
Conventional cyclic voltammetry (CV) experiments for investigating the electrode reaction process of potassium ferricyanide are performed under static conditions, which inherently limits the ability to assess mass transport effects on reaction rates. While this approach yields thermodynamic parameters such as peak potential difference (△E_p), it provides insufficient insight into reaction kinetics, consequently restricting students’ comprehensive understanding of the reaction mechanism. To address these limitations in instrumental analysis teaching, we developed an innovative experimental approach incorporating Rotating Ring-Disk Electrode (RRDE) technology to establish a multi-parameter detection platform. The disk electrode scans the primary reduction reaction of potassium ferricyanide, while the ring electrode simultaneously captures intermediate byproducts through constant potential oxidation. By applying the Koutecký-Levich equation, we quantitatively analyze the competitive relationship between mass transport and reaction kinetics. Students gain deeper mechanistic understanding by calculating the kinetic current density and byproduct distribution ratio. Furthermore, optimized electrode preparation and reaction environment cleanliness enabled measured △E_p values to approach thermodynamic ideal values. This experimental design overcomes the constraints of traditional static systems and provides an innovative approach for connecting electrochemical education with advanced research. The improved experiment has been successfully implemented in our “Instrumental Analysis Experiment” course for third-year chemistry majors, reaching 176 students across six classes over two semesters.
2026, 41 (5): 91-100. DOI: 10.12461/PKU.DXHX202511082

β-Borylation of carvone: an experiment to demonstrate reaction selectivities
Guanghuan Chen, Yinghua Wang, Jinhui Ming, Jian Ling, Zhihui Shao, Chongdao Lu, Yong Shi
Reaction selectivity constitutes a fundamental concept in both organic chemistry education and scientific research. As the relevant instructional content is typically scattered across different chapters, students often struggle to develop a systematic understanding of this concept. To address this pedagogical challenge, we have designed a teaching experiment demonstrating the chemo-, regio-, and stereoselective β-borylation of carvone with bis(pinacolato)diboron, catalyzed by copper(I) chloride and sodium methoxide. This innovative experiment effectively integrates and visually demonstrates various aspects of reaction selectivity, thereby demystifying the concept and fostering comprehensive student comprehension. The experiment also provides training in fundamental laboratory techniques while incorporating multiple elements suitable for quality-oriented education, making it particularly appropriate for undergraduate organic chemistry laboratory instruction.
2026, 41 (5): 101-108. DOI: 10.12461/PKU.DXHX202510042

Gather the light into glory: efficient preparation of aggregation induced emission fluorescent molecules by Suzuki coupling reaction for latent fingerprint detection
Senqiang Zhu, Ruohan Li, Yujia Yang, Jinzhi Liao, Rui Liu
This study employed Suzuki coupling reaction to synthesize potassium 5-(4-(diphenylamino)phenyl)thiophene-2-carboxylate (TTC) from 4-triphenylamineboronic acid and 5-bromo-2-carboxythiophene through a series of unit operations including heating, refluxing, filtration, extraction, and drying. The molecular structure and photophysical properties of TTC were systematically characterized using ¹H nuclear magnetic resonance (NMR) spectroscopy, UV-vis absorption spectroscopy, and fluorescence emission spectroscopy. Results demonstrate that the synthesized compound exhibits efficient blue-light emission and remarkable aggregation-induced emission (AIE) characteristics. Building upon these findings, we developed a practical application by designing a latent fingerprint detection protocol. The organic fluorophore serves as an effective fingerprint developer, enabling rapid visualization of high-quality fingerprint images with clear tertiary ridge characteristics. Fingerprint matching was performed using MATLAB-based recognition system. This experiment establishes a complete pedagogical framework encompassing chemical synthesis, material characterization, and application exploration. Preliminary implementation shows excellent experimental reproducibility with visually striking results, effectively stimulating student interest. Through this comprehensive training, students not only acquire interdisciplinary knowledge, but also develop systematic research thinking spanning molecular design, property modulation, and functional applications, while mastering essential techniques in organic synthesis, photophysical characterization, spectral analysis, and fingerprint development.
2026, 41 (5): 109-119. DOI: 10.12461/PKU.DXHX202511066

From insects to edible pigments: unveiling the color chemistry of cochineal
Ziwei Yang, Chenxi Zhang, Yu Duan, Yanxue Shang, Shunmei He
Cochineal, a natural animal pigment extracted from female cochineal insects (Dactylopius coccus) that parasitize cacti, is widely utilized in food, pharmaceutical, and cosmetic industries due to its safety and non-toxic properties. This popular science experiment investigates the chromatic transition (orange-red-purple) of cochineal in solutions with varying pH levels, along with its colorimetric reactions with metal ions (copper, iron, calcium) to form distinct complexes. The chemical principles underlying these phenomena were examined through UV-Vis absorption spectroscopy. By leveraging cochineal’s color-changing properties, we developed two types of colorimetric cards for public science education, demonstrating applications in pH determination, metal ion identification, and concentration measurement in common consumer products including foods, daily necessities, and health supplements. The experiment features environmentally friendly reagents, straightforward procedures, visually striking results, and high safety standards, making it particularly suitable for multi-level chemical education targeting K-12 students and the general public. This work highlights the unique scientific and societal value of natural animal-derived pigments through engaging hands-on demonstrations.
2026, 41 (5): 120-130. DOI: 10.12461/PKU.DXHX202509113

Improvement on the experimental determination of ionization equilibrium constant for acetic acid
Chunfang Zhang, Yuehua Liu, Lin Yang, Wenhui Xu, Mingtao Run, Cuimiao Zhang
This study comprehensively reforms the classic physical chemistry experiment involving the determination of the ionization equilibrium constant of acetic acid via conductometry. It addresses three key limitations: insufficient support for inquiry-based learning, lack of microscopic mechanistic insight, and reliance on conventional data processing methods. The reform incorporates three main strategies: expanding experimental protocols to enhance exploratory learning, introducing theoretical calculations to elucidate microscopic mechanisms, and implementing a custom-developed WeChat mini-program for intelligent data processing. These improvements significantly elevate the project’s “high-order, innovative, and challenging” quality, presenting a practical paradigm for a novel teaching model that effectively integrates theory and experimentation.
2026, 41 (5): 131-140. DOI: 10.12461/PKU.DXHX202511002

Preparation of benzofuran-5-formaldehyde based on formylation conjugated dehydrogenation tandem strategy: a recommended comprehensive teaching experiment for basic organic synthesis
Haolin Yang, Aoxiang Fan, Yi Song, Yang Chen
This study innovatively designs a comprehensive teaching experiment for synthesizing benzofuran-5-carbaldehyde through a tandem strategy involving formylation and conjugated dehydrogenation. Applying the principle of integrating theory with practice, we conducted in-depth mechanistic analysis and systematic optimization of the experimental procedure. Using commercially available 2,3-dihydrobenzofuran as starting material, the target product was successfully obtained via sequential Vilsmeier-Haack formylation and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated dehydrogenation, achieving an overall yield exceeding 80%. Subsequent low-temperature crystallization enhanced the final product purity to over 95%. This comprehensive experiment features operational simplicity, cost-effective materials, controllable duration, and minimal safety risks, meeting the “High-level, Innovative and Challenging” requirements for undergraduate laboratory education while effectively cultivating students’ innovative thinking and research skills.
2026, 41 (5): 141-148. DOI: 10.12461/PKU.DXHX202511156

“Ma Liang and his magic brush”: a science demonstration of creative painting using thermochromic pigments
Quan Liu, Jian Feng, Yuekun Qu, Jiayao Bai, Xunian Ren, Qi Wang, Haitao Xu, Shengrui Zhang
As an important subclass of xanthene dyes, fluorane dyes represent a significant group of heterocyclic compounds. Their molecular structure exhibits remarkable responsiveness to external stimuli, leading to distinct color changes. Owing to their excellent photophysical properties, fluorane dyes find substantial applications in biological imaging as bioactive structures, dyes, or fluorescent reagents. This science popularization experiment employs fluorane dye as the functional component to prepare microencapsulated fluorane dyes. The prepared dye microcapsules were formulated into inks to demonstrate thermochromic phenomena through oil and gouache painting techniques. To enhance accessibility for kindergarten and elementary school children, we further developed the dye ink into an instrumented form by designing an ink-filled thermochromic brush. The brush features compact size, lightweight construction, and portability, while all required materials are readily available, significantly reducing experimental preparation efforts. Through interactive demonstrations, this experiment allows participants to witness the marvels of scientific transformations, thereby fostering their interest in chemistry.
2026, 41 (5): 149-158. DOI: 10.12461/PKU.DXHX202511095

Improvement and extension of diphenylmethane synthesis experiment
Xi Tan, Chunhong Chen, Lijia Leng, Yulong Zhang
Carbonyl reduction reactions constitute a fundamental component in organic chemistry education. In current undergraduate laboratory instruction, this transformation is predominantly demonstrated through the Huang-Minlon reduction method, a pivotal method developed in China. However, this conventional experiment presents several pedagogical challenges, including the use of highly toxic hydrazine hydrate, excessive high-temperature byproduct formation, cumbersome workup procedures, and notable safety concerns. To address these limitations, we have implemented the following modifications to the diphenylmethane synthesis experiment: 1) replacement of the N₂H₄·H₂O-KOH system with an environmentally benign Polymethylhydrosiloxane (PMHS)-FeCl₃ reduction system; 2) substitution of hazardous diethylene glycol solvent (which releases toxic and irritating fumes at elevated temperatures) with stable and easily handled 1,2-dichloroethane; 3) reduction of reaction temperature from 140–195 to 70 ℃; 4) shortening of reaction duration from 4 to 1 h; and 5) adoption of a simplified workup procedure involving grinding and vacuum filtration instead of complex and potentially hazardous reduced-pressure distillation. Furthermore, by incorporating analytical techniques such as thin-layer chromatography, column chromatography purification, and spectroscopic characterization (Infrared Spectroscopy (IR) and Nuclear Magnetic Resonance (NMR)), we have developed this into an 8-hour comprehensive experiment. The extended protocol includes selective deoxygenative reduction of the pharmaceutical compound ketoprofen, thereby enhancing students’ comprehensive chemical competencies.
2026, 41 (5): 159-169. DOI: 10.12461/PKU.DXHX202511049

Exploration of improvement in polymer chemistry experiment based on the integration of industry and education: a case experiment of styrene-acrylic emulsion synthesis and performance test
Haozhe Huang, Pengjun Chen, Xiao Han, Junjie Bao
The synthesis and performance evaluation of styrene-acrylic emulsion represents a classical experiment in polymer chemistry education. Incorporating contemporary industrial applications of styrene-acrylic emulsions into laboratory instruction is a crucial component for achieving effective integration of industry and education. Current teaching materials employ octylphenol polyoxyethylene ether (OP-10) as an emulsifier. In recent years, OP-10 has been restricted by some industries due to environmental concerns. Furthermore, existing curricula are less involved practical applications of these emulsions, limiting the stimulation of students’ interest. This experiment implements an industry-aligned approach by utilizing the environmentally friendly reactive emulsifier allyloxy fatty alcohol polyoxyethylene ether ammonium sulfate (SR-10) for emulsion synthesis. We optimized experimental parameters including emulsifier dosage, initiator concentration, and glass transition temperature to align with industrial practices. Performance evaluation followed updated industry standards, and the emulsion was used to water-based inks for screen printing. This experiment enhances students’ awareness of industrial standards, develops their practical engineering skills, and increases their learning motivation.
2026, 41 (5): 170-179. DOI: 10.12461/PKU.DXHX202511160

Amine-trapping glow: synthesis and sensing applications of a highly sensitive amine-responsive aggregation-induced emission probe
Xinrong Wu, Yingying Ren, Jianxue Wang, Lijin Yang, Jia Jia, Nan Li, Na Zhao
This work bridges cutting-edge aggregation-induced emission (AIE) research with undergraduate education by developing an 8-hour comprehensive chemistry experiment. The laboratory exercise encompasses the synthesis and characterization of quinazoline derivatives 2-(2-hydroxyphenyl)quinazolin-4(3H)-one (HPQ) and 2-(2-(acetyl)phenyl)quinazolin-4(3H)-one (APQ), examination of HPQ’s AIE characteristics, and evaluation of APQ’s fluorescence response to amine vapors. The practical applications extend to invisible ink development and meat freshness detection. By demonstrating observable phenomena and real-world applications, this experiment effectively engages students’ research interests while systematically developing their synthetic skills, characterization techniques, and scientific reasoning abilities, thereby enhancing both professional competency and innovative capacity.
2026, 41 (5): 180-189. DOI: 10.12461/PKU.DXHX202509129

Tandem S_NAr/Aldol condensation for the constructruction of quaternary carbon-containing fused indoline
Fengcheng Jia, Zixia Zheng, Fei Li, Huiqin Duan, Gang Wang
Current undergraduate organic chemistry experiments predominantly focus on simple single-step reactions, with limited exposure to one-pot tandem reactions. This experiment employs cost-effective and readily available starting materials, 3-methyl-2-indolinone and 2-chloro-5-nitroacetophenone, to demonstrate a tandem process combining aromatic nucleophilic substitution (S_NAr) with Aldol condensation. The methodology enables the synthesis of 2,3-fused indoline derivatives featuring a quaternary carbon center. The experiment incorporates substantial theoretical concepts while maintaining operational simplicity, reaction stability, and excellent reproducibility.
2026, 41 (5): 190-197. DOI: 10.12461/PKU.DXHX202511104

“Tracing the light, revealing criminal traces”: novel intelligent fluorescent probe technology deciphering crime scene evidence
Hailong Zhang, Yiqin Yu, Ping Zhang, Xiuying Wang, Chusen Huang
Under the national policy framework promoting technological innovation and science popularization, this project implements the Strategy of Reinvigorating China through Science and Education. Focusing on chemical technology, we developed dual science outreach initiatives addressing judicial identification requirements. The research team created an innovative fluorescent probe fingerprint developer, which integrates with portable devices to enable one-stop rapid processing at crime scenes. The project established a gradient science communication approach to transform complex scientific principles into publicly accessible content, thereby contributing to judicial security system development while enhancing both public scientific literacy and legal safety awareness.
2026, 41 (5): 198-209. DOI: 10.12461/PKU.DXHX202510051

Synthesis of a bioisostere of the anticancer drug Alectinib
Weizhe Liu, Minghui Shi, Ruiqi Zhu, Bin Pan, Guofu Huang
This study focused on the first-line anticancer drug Alectinib, designing and synthesizing a furan-based intermediate through a three-step reaction sequence using cost-effective and readily available starting materials. The optimized protocol minimized intermediate isolation and purification steps, achieving completion within 8 hours with a consistent yield of 75%–80%, making it suitable for undergraduate laboratory instruction. Structural characterization by proton nuclear magnetic resonance spectrum (¹H NMR) and mass spectrometry (MS) enhanced students’ analytical skills while familiarizing them with standard organic synthesis workflows. The experiment successfully integrated ideological education (highlighting the national security significance of original drug development) with multidisciplinary knowledge spanning organic chemistry (condensation and substitution reactions), medicinal chemistry (bioisosterism), and spectroscopic analysis (NMR and MS). Designed to cultivate problem-solving abilities, this pedagogical approach introduces cutting-edge pharmaceutical research while fostering interdisciplinary thinking and lifelong learning principles. Through tiered learning objectives, the experiment accommodates diverse student capabilities, serving as an innovative model for integrating theoretical and practical education in organic and medicinal chemistry.
2026, 41 (5): 210-221. DOI: 10.12461/PKU.DXHX202510066

Electrochemical synthesis of 4-chloro-2-(triisopropylsilyl) quinoline
Mengyun Wu, Yuxin Deng, Wenhui Wang, Dongdong Xu, Langui Xie, Peipei Sun
Conventional organic reaction mechanisms primarily encompass three categories: ionic reactions, concerted reactions, and radical reactions. While current undergraduate organic chemistry laboratory curricula predominantly emphasize the first two types, radical reactions remain notably underrepresented. This pedagogical gap necessitates the inclusion of relevant experimental procedures to facilitate students’ fundamental comprehension of radical reactions and their condition optimization. Given that organosilicon compounds not only serve as crucial synthetic intermediates but also demonstrate diverse biological activities and substantial applications in materials chemistry, this experiment employs 4-chloroquinoline and triisopropylsilane as starting materials to synthesize 4-chloro-2-triisopropylsilylquinoline through an electrochemically mediated radical pathway. Designed for undergraduate chemistry education, this experiment integrates radical chemistry with modern electrochemical synthesis techniques, aiming to broaden students’ perspectives on reaction mechanisms, introduce contemporary synthetic methodologies, foster innovative thinking, and enhance engagement with organic chemistry. The protocol adheres to green chemistry principles, exhibiting superior characteristics including operational efficiency, exceptional atom economy, high product yield, and excellent reproducibility.
2026, 41 (5): 222-229. DOI: 10.12461/PKU.DXHX202511044

Preparation of spherical nucleic acids and their application to DNA detection
Ruilin He, Fengyi Wang, Zhikai Xia, Linling Zheng, Yue Liu
Sols represent a class of widely utilized nanomaterials in biomedical applications, demonstrating extensive utility in biosensing, bioimaging, and biomedicine. Building upon existing fundamental research on sol properties, further experimental investigations into their modification and applications hold significant value for expanding medical students’ knowledge of cutting-edge sol technologies and enhancing their understanding of medical applications. Spherical nucleic acids (SNAs) stand as the most mature and exemplary model of sol modification and application. Incorporating our research team’s innovative findings on SNA preparation, this study develops a novel experimental protocol for SNA synthesis and application specifically designed for medical laboratory technology education. The experiment systematically combines gold sol synthesis, SNA preparation (through DNA modification of gold sols), and DNA detection applications. With its innovative content and logically progressive design, this experiment effectively stimulates students’ investigative interest. Results indicate that this newly developed protocol offers simple operation, eliminates the need for large-scale instrumentation, ensures environmental safety, and demonstrates excellent feasibility and reproducibility, making it highly suitable for undergraduate laboratory instruction. This project-oriented approach, focusing on cultivating scientific innovation literacy, integrates theoretical knowledge with practical problem-solving while maintaining an appropriate level of challenge, thereby enhancing students’ ability to comprehensively apply knowledge for analytical problem-solving.
2026, 41 (5): 230-238. DOI: 10.12461/PKU.DXHX202511108

From a faint glow to a radiant blaze: the fascinating journey of sodium percarbonate “lighting up” luminol chemiluminescence
Xun Pei, Jiahui Liu, Haozhuo Liu, Qiuhong Wei, Xiaocui Chen, Ranxiao Tang
This study develops a public-oriented science communication system featuring chemiluminescence experiments using luminol and sodium percarbonate (commonly called “oxygen-releasing salts”) as core reactants. We successfully transitioned the conventional liquid-phase luminol luminescence reaction into a solid-state system by creating a “luminescent powder” mixture of luminol and sodium percarbonate, which emits cold light under specific conditions to form an intuitive, easily operable visual demonstration. The experiment progresses through three conceptual phases: “Principles of Chemiluminescence”, “Applications of Chemiluminescence”, and “Aesthetics of Chemiluminescence”, elucidating the reaction mechanism of luminol glow, establishing rapid identification methods for oxygen-releasing salt components, and integrating the luminous phenomenon with lighting art, cultural connections, and scientific heritage. Employing a dual-channel dissemination strategy combining online and offline approaches with tiered content design, this system effectively stimulates scientific interest and practical engagement across age groups. The solid-state luminescence system demonstrates notable advantages in operational simplicity and adaptability, with potential applications spanning science education, cultural innovation, and public communication. This research exemplifies the multidimensional integration of fundamental chemical knowledge with daily life, aesthetic experiences, and science communication, pioneering a new pathway for chemistry outreach that progresses from “perceivable” to “understandable”.
2026, 41 (5): 239-251. DOI: 10.12461/PKU.DXHX202511119

Innovation and extension of phosphonium salt synthesis: aqueous one-step synthesis of ethyltriphenylphosphonium bromide and preparation and characterization of its mechanoluminescent manganese complex
Ranhui Fu, Shixin Zhou, Ran Ji, Feifei Gao, Hui Xu
In response to China’s “101 Plan” for cultivating top-tier innovative talents in fundamental disciplines, this study addresses key limitations in traditional phosphonium salt synthesis experiments, including high solvent toxicity, lengthy reaction times, and poor operational experience. We developed an environmentally friendly aqueous one-step synthesis method for ethyltriphenylphosphonium bromide, eliminating toxic solvents while reducing reaction time to 2.5 h and improving yield to 75%. The synthesized phosphonium salt was subsequently used to prepare a mechanoluminescent manganese complex. The pedagogical design incorporates two modules: a foundational experiment (5.5 credit hours) and an advanced comprehensive experiment (9.5 credit hours), establishing an integrated experimental teaching system. This work transforms a conventional experiment into an interdisciplinary, practical, and cutting-edge comprehensive experiment, providing valuable insights for developing high-quality core experimental courses.
2026, 41 (5): 252-263. DOI: 10.12461/PKU.DXHX202510018

Basic experiment for Pourbaix diagram analysis and electrochemical performance optimization based on “bipolar” technology
Yijie Zhong, Yurun Tong, Weitao Wang, Ru Qiao, Jing Zhang, Enlai Hu, Peijun Gong
This study addresses the pedagogical challenges associated with Pourbaix diagrams in inorganic chemistry by incorporating bipolar membrane technology to develop a visualized experimental approach. Utilizing sodium alginate as the raw material, we fabricated a bipolar membrane and constructed an electrochemical cell to systematically investigate the effects of pH and overpotential on cell voltage. The experiment employs a blended online-offline teaching methodology with tiered experimental modules, facilitating interdisciplinary knowledge integration. Characterized by operational simplicity, reagent safety, and cost-effectiveness, this approach enhances students’ theoretical understanding and innovative thinking, making it particularly suitable for undergraduate chemistry education.
2026, 41 (5): 264-274. DOI: 10.12461/PKU.DXHX202511071

Mercury-free improvement of anodic stripping voltammetry for the determination of trace cadmium in water
Haobin Zhou, Shuai Du, Xuesong Guo, Yue Wang, Qin Zhong, Tong Wang, Yuzhi Wang, Shuangyan Huan, Hailong Yan, Kun Li
Anodic stripping voltammetry (ASV) employing mercury-film electrodes (MFEs) has been widely adopted as a standard technique for trace cadmium detection and incorporated into undergraduate laboratory programs. However, conventional MFEs present significant drawbacks including mercury contamination risks and poor reproducibility, along with excessive cadmium consumption during experiments. In this study, we developed an innovative mercury-free electrode utilizing a composite material of low-toxicity eutectic gallium-indium (EGaIn) alloy and electrochemically reduced graphene oxide (erGO). By implementing square-wave voltammetry instead of linear sweep voltammetry, an improved protocol for trace cadmium determination was established. Experimental results demonstrated substantial enhancements in signal stability and sensitivity. Notably, the modified method reduced cadmium consumption by over two orders of magnitude while decreasing experimental costs by approximately 50%, showcasing its environmental and economic advantages. This redesigned experiment integrates multidisciplinary concepts from analytical chemistry, materials science, and physical chemistry, addressing contemporary environmental concerns while providing a safer, cost-effective alternative. The approach not only enhances students’ practical skills but also fosters research interest and innovative thinking in electroanalytical chemistry, making it highly suitable for undergraduate laboratory education.
2026, 41 (5): 275-284. DOI: 10.12461/PKU.DXHX202511142

Design of conjugated polymer probes for intelligent detection of phycocyanin
Junjie Zhang, Chaochao Dong, Jinke Li, Jiawen Guo, Yingxin Shui, Yue Wang, Xinhua Duan
This study addresses ecological security concerns through early warning of cyanobacterial blooms by developing an innovative 12-hour comprehensive undergraduate experiment. The curriculum integrates conjugated polymer fluorescent probes for phycocyanin detection into four modules: probe synthesis, instrumental characterization, method development, and sample analysis, incorporating multidisciplinary knowledge from organic chemistry, polymer chemistry, analytical chemistry, and instrumental analysis. Our self-developed portable intelligent fluorescence sensing platform significantly enhances teaching efficiency and student engagement while promoting the coordinated development of experimental skills, data analysis capabilities, innovative thinking, and research competence. Characterized by low cost, operational simplicity, and high safety, this experiment effectively bridges fundamental techniques with advanced understanding of structure-property-application relationships, making it ideal for upper-level chemistry majors in “Comprehensive Chemical Experiment” courses. The probe design demonstrates universal applicability for various target analytes, and the versatile, cost-effective sensing platform shows excellent potential for widespread adoption in fluorescence-based experimental teaching.
2026, 41 (5): 285-293. DOI: 10.12461/PKU.DXHX202509114

Black and white battle: humic acid, the savior of saline-alkali land
Xingsheng Liu, Xinru Li, Zhuoqun Liu, Quanlong Liu, Xiaoran Sun, Bowu Zhao, Chao Han
This study investigates the application of humic acid in saline-alkali soil remediation as a science communication topic. Through comprehensive experiments and public demonstrations, we validate its significant effects on improving soil structure and reducing salinization. The experimental design includes humic acid’s role in promoting soil aggregate formation, production methods via composting, quantitative analysis of humic acid content, and soil amendment planting trials. Our results demonstrate that humic acid effectively enhances soil aggregation and increases seed germination rates. Additionally, we developed tailored science communication programs for diverse age groups and social demographics. Using interactive experiments and engaging visual materials, we successfully translated complex scientific principles into accessible ecological practices, facilitating public participation in saline-alkali land remediation.
2026, 41 (5): 294-306. DOI: 10.12461/PKU.DXHX202511101

“Traditional Chinese medicine” meeting “medicine”: a popular science experiment explaining scientific medication from a chemical perspective
Juanjuan Song, Ling Xu, Jinghai Liu, Kaige Li, Jiayi Li, Yihao Li
Traditional Chinese medicine (TCM) has a profound history as a valuable cultural heritage of the Chinese nation and is widely utilized in daily life. However, most TCM formulations derived from natural sources contain complex compositions, and users often overlook the intricate interactions between medicinal components and critical usage details. Such oversight may result in reduced efficacy or delayed treatment at best, or potentially lead to poisoning and life-threatening consequences at worst. This study addresses these concerns through a tiered science communication approach, employing commonly used TCM materials including Chebula fruit, Coptidis Rhizoma, and black wolfberry in engaging experimental demonstrations. The experiments illustrate precipitation reactions between tannic acid-containing drugs (e.g., Chebula) and Fe³⁺, proteins, or ibuprofen-class medications, as well as alkaloid-containing drugs (e.g., Coptidis Rhizoma). Additionally, we demonstrate color-changing reactions of anthocyanin-containing drugs (e.g., black wolfberry) under varying pH conditions. These phenomena not only affect drug efficacy by altering active components but may also cause adverse effects. Through intuitive experimental observations, this work aims to enhance public understanding of TCM, promote its modern scientific interpretation, disseminate knowledge about herbal compatibility, dietary contraindications, and consequences of improper use, thereby improving medication safety awareness.
2026, 41 (5): 307-318. DOI: 10.12461/PKU.DXHX202511166

Waste-treat-waste: a comprehensive laboratory experiment on catalytic glycolysis of PET plastics using recycled anode materials from discarded Zn-Mn batteries
Fangyu Leng, Jian Zhang, Yuwen Zhang, Yuchun Jiang, Xiaohong Chang, Jie Wei
The extensive utilization of alkaline zinc-manganese batteries and poly(ethylene terephthalate) (PET) plastics has resulted in substantial quantities of recyclable waste. Guided by the “resource recycling” principle of green chemistry, this work achieves a waste-treats-waste approach by employing recycled anode materials (Zn/ZnO) from spent zinc-manganese batteries to effectively catalyze PET glycolysis. We have developed a comprehensive laboratory experiment tailored for undergraduate students in chemistry and related disciplines. Battery disassembly enables students to visually examine zinc-manganese battery structures, thereby deepening their understanding of electrochemical power sources. The PET glycolysis process demonstrates the depolymerization of macromolecules, while product identification combines fundamental organic chemistry techniques (melting point determination) with advanced characterization methods (Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (¹H NMR)) for structural elucidation. This 8-hour experiment integrates core concepts and practical skills from inorganic, physical, organic, polymer, and analytical chemistry. Featuring straightforward procedures, cost-effective materials, and excellent reaction efficiency (100% PET conversion with 76.5% bis(2-hydroxyethyl) terephthalate (BHET) yield), the experiment not only enhances students’ comprehensive laboratory abilities but also effectively promotes green chemistry education principles.
2026, 41 (5): 319-329. DOI: 10.12461/PKU.DXHX202510077

A new exploration of quantitative detection of serum glucose based on biomimetically mineralized enzyme immobilized nanoprobe
Huairou Zhu, Qiaoyi Cen, Dan Yan, Wei Yi, Guosheng Chen, Siming Huang, Gangfeng Ouyang
The measurement of serum glucose represents a fundamental experiment in clinical biochemistry laboratory courses. However, current methodologies present several drawbacks, including the utilization of highly toxic chromogenic substrates, limited anti-interference capacity, and time-consuming instrumental analysis. This enhanced experimental protocol maintains the fundamental principle of enzyme cascade catalysis while implementing improvements in three critical dimensions: 1) substitution of the highly toxic 4-aminoantipyrine chromogen with the less hazardous 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), substantially improving operational safety; 2) development of a stable and sensitive nanoprobe through biomimetic enzyme immobilization technology, effectively enhancing both interference resistance and detection accuracy while elevating the experiment’s innovative and advanced characteristics; 3) replacement of traditional UV-Vis spectrophotometry with high-throughput microplate reader technology, significantly reducing analysis time and sample volume requirements. Teaching evaluations demonstrate that the synthesized nanoprobe features straightforward preparation, cost-effectiveness, excellent reproducibility, and superior detection accuracy. This optimized experiment successfully integrates teaching safety, advanced concepts, and cutting-edge technology. Its modular design enables completion within 7–10 instructional hours, offering a replicable model for reforming clinical biochemistry laboratory curricula.
2026, 41 (5): 330-339. DOI: 10.12461/PKU.DXHX202511041

Diamonds in wine?!: popular science experiments on the tartaric acid family
Tianjiao Hu, Jie Zhang, Juan Xie, Jin Li, Mianjue Wang
Tartaric acid and its salts represent a class of chemically significant compounds that are ubiquitous in daily life. This public science initiative investigates the phenomenon of tartar crystallization in wine through a series of carefully designed experiments, including tartaric acid extraction, simulated potassium hydrogen tartrate precipitation, and demonstrations of potassium sodium tartrate’s piezoelectric applications. The project serves dual purposes: it educates the public about the harmless nature of wine crystals while revealing the scientific principles behind common observations, and introduces the tartaric acid family’s chemical properties and practical applications, thereby highlighting chemistry’s crucial role in both everyday life and scientific advancement. Featuring straightforward protocols, safe operations, and visually striking results, these experiments effectively illustrate both the aesthetic and functional dimensions of chemistry. Utilizing diverse presentation methods such as exhibition panels, instructional videos, and hands-on activities, the project offers tailored engagement strategies for different audiences, aiming to stimulate adolescents’ interest in chemical sciences and promote public scientific literacy.
2026, 41 (5): 340-349. DOI: 10.12461/PKU.DXHX202511013

Photocatalytic oxidation synthesis of benzophenone promoted by vitamin B₂
Zhiqiang Hao, Jinyue Li, Shiqi Zhang, Yujia Hou, Helue Sun
The synthesis of benzophenone represents a fundamental organic chemistry experiment in current undergraduate laboratory curricula. However, conventional methods suffer from several drawbacks, including the requirement for excessive oxidizing agents, the use of highly toxic benzene as starting material, and complex operational procedures. Aligned with green chemistry principles, this modified experiment incorporates photocatalytic synthesis technology for benzophenone production, employing vitamin B₂ (riboflavin) as a photocatalyst and molecular oxygen from air as the oxidant under visible light irradiation. The improved protocol eliminates the need for metal catalysts while offering advantages of mild reaction conditions, operational simplicity, and cost-effectiveness. By integrating cutting-edge photochemical synthesis concepts into undergraduate laboratory education, this approach provides a safe, efficient, and environmentally benign experimental model. The experiment not only deepens students’ understanding of photocatalytic reactions and green chemistry principles, but also fosters innovative thinking and cultivates scientific reasoning skills.
2026, 41 (5): 350-357. DOI: 10.12461/PKU.DXHX202510080

Visible light catalysis for green synthesis of dipeptides
Xiaomei Ai, Muran Lin, Jinlan Zeng, Jiwei Ren
This study presents a visible-light-induced photocatalytic strategy employing triphenylphosphine-promoted deoxygenative amidation for dipeptide synthesis. Utilizing an iridium metal complex as the catalyst under blue light irradiation, N-protected amino acids generate acyl radicals that subsequently couple with amino acid esters to form dipeptides. The method demonstrates high product yields and exceptional diastereoselectivity. This protocol features cost-effective reagents, mild reaction conditions, operational simplicity, environmental friendliness, high efficiency, and excellent reproducibility, with the entire process completable within an 8-hour timeframe.
2026, 41 (5): 358-367. DOI: 10.12461/PKU.DXHX202510007

“Green synergy, optimized synthesis”: improvement of synthesis experiment of benzocaine
Xin Lai, Ruiyao Lin, Siqin Lin, Ruiqi Han, Qi Li
This study presents an optimized synthesis protocol for benzocaine, modifying the conventional experimental procedures described in both Organic Chemistry and Medicinal Chemistry laboratory manuals. Building upon the traditional synthetic route, this experiment substitutes potassium permanganate as the oxidant with tetrabutylammonium bromide as a phase-transfer catalyst, enabling safer oxidation of p-nitrobenzoic acid under neutral conditions. The esterification catalyst is replaced by sodium bisulfate monohydrate coupled with ultrasonic irradiation to enhance ethyl p-nitrobenzoate synthesis efficiency. An ultrasonic assistance is finally applicated to improve yield in the acetic acid-iron powder reduction step. Comparative results demonstrate that the modified protocol achieves an 82.2% increase in overall yield, reduces total reaction time by 35.3%, utilizes fewer reagents, and simplifies post-processing compared to conventional methods. The experimental design consistently incorporates green chemistry principles while integrating multidisciplinary knowledge and techniques, thereby enhancing students’ professional competencies and offering substantial pedagogical value with potential for broader application.
2026, 41 (5): 368-379. DOI: 10.12461/PKU.DXHX202511167

Chiral analysis of amino acids using electronic circular dichroism spectroscopy combined with quantum chemical calculation: a comprehensive computational chemistry experiment
Qi Liang, Xinxin Wang, Xinmiao Zhao, Mohan Yu, Yue Sun
This innovative undergraduate experiment integrates instrumental characterization through electronic circular dichroism (ECD) spectroscopy with quantum chemical computational methods to address the growing need for interdisciplinary curriculum development. The experimental protocol involves recording ECD spectra of chiral amino acids, screening and optimizing dominant molecular conformations, and computing theoretical spectra. Comparative analysis between experimental and computational results enables absolute configuration determination while facilitating in-depth examination of transition properties. The exercise enhances students’ proficiency in operating advanced analytical instrumentation and performing ECD theoretical calculations, thereby strengthening their fundamental research competencies.
2026, 41 (5): 380-390. DOI: 10.12461/PKU.DXHX202511096

Preparation of polyacrylamide gel electrolyte and its application in flexible aqueous zinc-ion batteries
Xiaorong Ding, Aohan Hu, Siyu Zhang, Chongjiong Zheng, Long Su, Fei Lu
This study addresses the limitations of conventional electrochemical education, where knowledge is often fragmented and students struggle to develop a systematic understanding of the relationship between material preparation and performance applications. We present an integrated experiment focusing on the preparation of polyacrylamide (PAM) hydrogel electrolyte and its application in flexible aqueous zinc-ion batteries (FZIBs). The experimental design includes the complete workflow from material synthesis and property characterization to device integration and performance evaluation. Through a problem-driven approach involving experimental verification and practical application extension, students engage in hands-on activities including bending tests, conductivity measurements, battery assembly, and flexible device evaluation. This pedagogical model bridges cutting-edge research with engineering practice, providing a replicable solution to overcome the challenges of fragmented knowledge instruction while fostering the development of systematic thinking and engineering competencies in emerging engineering education.
2026, 41 (5): 391-397. DOI: 10.12461/PKU.DXHX202511037

Crab meets fluorescent special agent team: waste shell captures microplastics
Guangyue He, Hanxiao Liu, Chi Zhang, Yunsheng Li, Guanfeng Ji, Dawei Fan
This study addresses microplastics as an emerging environmental concern. Initially, microscopic examination revealed the release of plastic particles from disposable paper cups upon hot water exposure, visually demonstrating microplastic contamination risks. Employing kitchen waste-derived crab shells as a primary material, we developed an optimized household experiment with a dual-purpose strategy: fabricating porous crab shells via acid-base treatment for nanoplastic adsorption, and synthesizing carbon quantum dots through pyrolysis for nanoplastic quantification. This “adsorption-detection” experimental framework advances microplastic awareness from basic recognition to property investigation and remediation practice, thereby enriching science communication. The experiment’s waste solution was repurposed as plant nutrient solution, embodying green chemistry principles. Beginning with commonplace hot water-paper cup interactions, our approach makes invisible microplastics tangible, overcoming public perception barriers. The crab shell methodology not only enhances interactive learning but also demonstrates innovative applications for studying aged microplastic properties. Through tiered science communication, this work effectively promotes environmental consciousness and supports plastic pollution mitigation efforts.
2026, 41 (5): 398-411. DOI: 10.12461/PKU.DXHX202511058

“Magic transformation” of wood into water purifier
Liuqing Yang, Pengyu Chen, Yuhan Yang, Liguo Ye, Qiaochu Yang, Xiaofei Yang
This paper elucidates the carbonization and hydrophilization processes involved in the “magic transformation” of wood into a water purifier, along with its purification efficacy and underlying mechanisms. The wood-based purifier effectively removes contaminants such as microplastics (≥ 10 μm), organic dyes, and antibiotics from water, demonstrating successful purification of natural water samples from Nanjing’s Xuanwu Lake. Through hands-on demonstrations, informational displays, video presentations, and interactive quiz sessions, this project achieved public engagement and delivered accessible science communication. The study presents a novel practical model for chemical science education.
2026, 41 (5): 412-421. DOI: 10.12461/PKU.DXHX202510063

Design of a virtual-physical integrated experiment for developing green fungicide fenopyramide
Xinran Han, Jiaxin Li, Yuhan Kang, Qiongyou Wu
To meet the urgent demand for cultivating interdisciplinary talents in green pesticide innovation, this experimental design adopts a “research-integrated” approach to establish a virtual-physical hybrid teaching model that combines computer-aided screening, organic synthesis, and bioactivity evaluation. The model systematically integrates multiple disciplines including computational chemistry, organic chemistry, and chemical biology, while incorporating authentic research processes throughout the entire teaching workflow. Using succinate dehydrogenase (SDH) as the molecular target, the experiment focuses on the discovery and activity validation of the novel fungicide fenopyramide. The teaching process begins with molecular docking and virtual screening to help students understand target-oriented molecular design principles, followed by compound synthesis and structural characterization to enhance experimental and analytical skills. The final phase involves enzyme inhibition and hyphal growth inhibition assays, completing the full research cycle from molecular recognition to biological function validation. This modular design reflects the scientific logic of “theoretical construction–experimental verification–result analysis”, effectively fostering students’ interdisciplinary thinking, innovative capacity, and practical skills while creating an integrated platform for green pesticide development and experimental education.
2026, 41 (5): 422-429. DOI: 10.12461/PKU.DXHX202511113

Color code of urine sugar test strips
Jiamiao Zhao, Yun Zhou, Han Li, Xuejun Zhang, Liming Fan
Urine glucose test strips serve as a convenient tool for daily diabetes monitoring, playing a vital role in blood glucose management. This experiment elucidates the function, chemical principles, fabrication, and application of urine glucose test strips for public education. The detection mechanism involves glucose oxidase identifying glucose in urine, which subsequently generates gluconic acid and hydrogen peroxide under aerobic conditions. Tetramethylbenzidine undergoes redox reactions with hydrogen peroxide, catalyzed by peroxidase under weakly acidic conditions, yielding yellow imine ions. This colorimetric change enables qualitative or semi-quantitative detection of urine glucose. By integrating chemistry with health knowledge and practical applications, this experiment enhances public understanding of chemistry’s role in medical health monitoring.
2026, 41 (5): 430-437. DOI: 10.12461/PKU.DXHX202511125

Enjoy persimmons with satisfaction: a chemical adventure of tannic acid
Cuiping Zhai, Simin Huang, Yu Jin, Enming Lü, Mengdi Liu
While persimmons offer substantial nutritional value, their tannic acid content can interact with various substances upon ingestion, potentially posing health risks that are frequently overlooked in daily consumption. This popular science experiment selects common dietary items including persimmons, tea, milk, soy milk, eggs, and rice vinegar. By leveraging the chemical properties of tannic acid, we have developed an interactive demonstration framework suitable for participants of all ages. The initiative seeks to vividly convey the beauty of chemistry through engaging methodologies, address prevalent dietary misconceptions, and ultimately enhance public awareness regarding health and safety as well as scientific literacy.
2026, 41 (5): 438-447. DOI: 10.12461/PKU.DXHX202511134

Dual-signal-amplified functional nucleic acid fluorescence probe for ultrasensitive detection of antibiotic in water
Qinqi Zhang, Zhuoran Bi, Yi Zhong, Ziting Xu, Lanlan Chen
Functional nucleic acid probes demonstrate superior characteristics including high specificity, strong binding affinity, excellent stability, and cost-effectiveness. This study incorporates fundamental research concepts of molecular recognition and signal amplification into undergraduate laboratory education through carefully designed experiments and optimized operational procedures. We developed a dual-signal-amplified functional nucleic acid probe system that utilizes an aptamer as the molecular recognition element, coupled with hybridization chain reaction (HCR) and DNAzyme-mediated signal amplification. The detection mechanism employs thioflavin T (ThT) fluorescence upon binding to the G-quadruplex structure, achieving ultrasensitive detection of chloramphenicol in aqueous environments.
2026, 41 (5): 448-454. DOI: 10.12461/PKU.DXHX202511151

Preparation of flexible electrochemical sensors for on-site portable detection of heavy metal ions
Junlin Ma, Enze Wang, Haixia Wu
This study developed a flexible electrochemical sensor for rapid and highly sensitive detection of heavy metal ions (Hg²⁺, Cd²⁺). The flexible electrodes were fabricated using screen-printing technology, and a porous polypyrrole film was constructed via electropolymerization and molecular removal strategies to enhance ion enrichment and stripping current response. The sensor demonstrated detection limits of 0.0089 mg·L^-1 for Hg²⁺ and 0.0037 mg·L^-1 for Cd²⁺. The experimental design incorporates interdisciplinary cutting-edge knowledge, aiming to foster students’ interest in chemical research and raise awareness of environmental pollution issues.
2026, 41 (5): 455-468. DOI: 10.12461/PKU.DXHX202509102