Sensitive and Selective Detection of Oxo-Form Organophosphorus Pesticides Based on CdSe/ZnS Quantum Dots
AbstractA rapid, sensitive and enzyme-based optical biosensor was applied for the determination of seven organophosphorus pesticides (OPPs), including the oxo forms (malaoxon, paraoxon, dibrom, and dichlorvos), the thio forms (malathion and parathion) and the mixed form (demeton) in Panax ginseng. The principal of the proposed method is that the fluorescence quenching effect of quantum dots (QDs) can be observed by enzyme-generated H2O2. The active centers of acetylcholinesterase (AChE) could be inhibited in the presence of pesticides, which caused decrease of the generated H2O2. Then, the inhibition efficiency of pesticide to AChE activity could be evaluated by measuring the fluorescence changes. Different from biosensors based on immobilized enzyme or self-assembling technique, the proposed biosensor demonstrated a good selectivity for the detection of oxo forms of OPPs. In the present study, the important experimental conditions of the proposed biosensor were investigated. Under the optimized conditions (incubation temperature, 35 °C; incubation time, 20 min; pH value, 8.0; detection time, 30 min; AChE concentration, 40.9 U/L; and choline oxidase (ChOx) concentration, 637.5 U/L), the limit of detection for the investigated oxo-form OPPs was no more than 0.05 μM, which suggested that the proposed method could be used for sensitive and selective determination of trace amounts of OPPs residues in real samples with complex matrices. View Full-Text
- Supplementary File 1:
Supplementary (PDF, 333 KB)
Share & Cite This Article
Wei, J.; Cao, J.; Hu, H.; Yang, Q.; Yang, F.; Wan, J.; Su, H.; He, C.; Li, P.; Wang, Y. Sensitive and Selective Detection of Oxo-Form Organophosphorus Pesticides Based on CdSe/ZnS Quantum Dots. Molecules 2017, 22, 1421.
Wei J, Cao J, Hu H, Yang Q, Yang F, Wan J, Su H, He C, Li P, Wang Y. Sensitive and Selective Detection of Oxo-Form Organophosphorus Pesticides Based on CdSe/ZnS Quantum Dots. Molecules. 2017; 22(9):1421.Chicago/Turabian Style
Wei, Jinchao; Cao, Jiliang; Hu, Hao; Yang, Qing; Yang, Fengqing; Wan, Jianbo; Su, Huanxing; He, Chengwei; Li, Peng; Wang, Yitao. 2017. "Sensitive and Selective Detection of Oxo-Form Organophosphorus Pesticides Based on CdSe/ZnS Quantum Dots." Molecules 22, no. 9: 1421.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.