Abstract:

As we all know, heavy metal ions are difficult to degrade in nature, and a certain amount of heavy metal ions will be enriched in living organisms, which seriously threatens the health of life. Yunnan Province has abundant freshwater resources in plateau lakes. The research on heavy metal pollution in plateau lakes is conducive to in-depth understanding of the current situation of heavy metal pollution in plateau lakes, which can provide a basis for its comprehensive control. Fluorescent nanoprobes exhibit advantages such as high sensitivity, good selectivity and simple operation in the detection of heavy metal ions. Three nanomaterials with different fluorescence-emission including carbon dots (CDs, blue), quantum dots (CdTe QDs, green), and gold nanoclusters (Au NCs, red) were successfully synthesized. Then, the above three fluorescent nanoprobes and the mixed ratiometric probes of CDs and Au NCs were added into the 96-well plate to form a 5 × 12 array which was used to detect Pb²⁺, Cu²⁺ and Hg²⁺ in the plateau lake water sample based on the fluorescence quenching and ratiometric fluorescence. In addition, the RGB values of the above solution in 96-well plate were recorded by APP-Colorimeter X in smartphone under the ultraviolet lamp. This proposed method exhibited superior testing performances toward Pb²⁺, Cu²⁺ and Hg²⁺, including portability, high-throughout, sensitivity, good visual effect, miniaturization, and small volume. Finally, this newly created experiment can solve the shortage problems of experimental instruments in some universities, boring undergraduate experiments, and derailment with the frontier of scientific research, which can facilitate the development of comprehensive experiments in universities.

Key words: RGB array analysis, Fluorescent nanoprobe, Smartphone detection, Plateau lake, Heavy metal ions