Fluorescence Sensor Based on Biosynthetic CdSe/CdS Quantum Dots and Liposome Carrier Signal Amplification for Mercury Detection

• Published in: Analytical chemistry (Washington) 2020-03, Vol.92 (5), p.3990-3997
• Main Authors: Zhang, Yi, Xiao, Jing-Yu, Zhu, Yuan, Tian, Li-Jiao, Wang, Wei-Kang, Zhu, Ting-Ting, Li, Wen-Wei, Yu, Han-Qing
• Format: Article
• Language: English
• Subjects: Amplification; Analytical chemistry; Aquatic environment; Biocompatibility; Cadmium Compounds - chemistry; Cadmium selenides; Cadmium sulfide; Chemistry; DNA probes; DNA, Single-Stranded - chemistry; Drinking water; Environmental Monitoring; Fluorescence; Fresh Water - analysis; Health risks; Hydrogen-Ion Concentration; Ion probes; Landfills; Leachates; Limit of Detection; Liposomes - chemistry; Low concentrations; Mercury; Mercury (metal); Mercury - analysis; Metal ions; Pollutants; Pollution detection; Quantum dots; Quantum Dots - chemistry; Rivers; Selectivity; Selenium Compounds - chemistry; Sensors; Single-stranded DNA; Spectrometry, Fluorescence - methods; Sulfides - chemistry; Thymine; Thymine - chemistry; Waste disposal sites; Water Pollutants, Chemical - analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.9b05508

Mercury (Hg), as a highly harmful environmental pollutant, poses severe ecological and health risks even at low concentrations. Accurate and sensitive methods for detecting Hg2+ ions in aquatic environments are highly needed. In this work, we developed a highly sensitive fluorescence sensor for Hg2+ detection with an integrated use of biosynthetic CdSe/CdS quantum dots (QDs) and liposome carrier signal amplification. To construct such a sensor, three single-stranded DNA probes were rationally designed based on the thymine–Hg2+–thymine (T–Hg2+–T) coordination chemical principles and by taking advantage of the biocompatibility and facile-modification properties of the biosynthetic QDs. Hg2+ could be determined in a range from 0.25 to 100 nM with a detection limit of 0.01 nM, which met the requirements of environmental sample detection. The sensor also exhibited a high selectivity for Hg2+ detection in the presence of other high-level metal ions. A satisfactory capacity of the sensor for detecting environmental samples including tap water, river water, and landfill leachate was also demonstrated. This work opens up a new application scenario for biosynthetic QDs and holds a great potential for environmental monitoring applications.