Abstract: 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.

Key words: Nucleic acid aptamer, Hybridization chain reaction cycle, DNAzyme, Ultrasensitive detection, antibiotics