CdSe-ZnS Quantum Dots for Selective and Sensitive Detection and Quantification of Hypochlorite

Four types of water-soluble quantum dots (QDs) grafted with different organic coating layers were fabricated, and their sensitivities for hypochlorite/hypochlorous acid (HC10) were examined It was found that QDs with HCIO reactive (methylamino and sulphide groups) coating layers exhibited a protective effect on HC10 quenching of QD fluorescence, whereas QDs with hydrocarbon and car boxylate coating layers showed least protection to QD fluorescence quenching by HCIO and, thus, has the highest sensitivity for the detection of HCIO The QDs with carboxylate coating layers (QDs poly-CO2-) was successfully applied to the quantification of HCIO in tap water The excellent selectivity of the QDs-poly-CO2- toward hypochlorite against other reactive oxygen species allowed us to monitor myeloperoxidase activity Finally, the QDs poly CO2- was also used for the detection of hypochlorite in HL60 cells by fluorescent imaging Hence, QD poly-CO2- exhibits great promise as a selective and sensitive HCIO probe in chemical and biological systems