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

Abstract

Four types of water-soluble quantum dots (QDs) grafted with different organic coating layers were fabricated, and their sensitivities for hypochlorite/hypochlorous acid (HClO) were examined. It was found that QDs with HClO reactive (methylamino and sulphide groups) coating layers exhibited a protective effect on HClO quenching of QD fluorescence, whereas QDs with hydrocarbon and carboxylate coating layers showed least protection to QD fluorescence quenching by HClO and, thus, has the highest sensitivity for the detection of HClO. The QDs with carboxylate coating layers (QDs-poly-CO(2)(-)) was successfully applied to the quantification of HClO in tap water. The excellent selectivity of the QDs-poly-CO(2)(-) toward hypochlorite against other reactive oxygen species allowed us to monitor myeloperoxidase activity. Finally, the QDs-poly-CO(2)(-) was also used for the detection of hypochlorite in HL60 cells by fluorescent imaging. Hence, QD-poly-CO(2)(-) exhibits great promise as a selective and sensitive HClO probe in chemical and biological systems.

Ethanol in aqueous hydrogen peroxide solution: Hydrothermal synthesis of highly photoluminescent carbon dots as multifunctional nanosensors

“…8b). The limit of detection is determined to be 0.08 μM based on a signal-to-noise ratio of 3, lower than that of other methods [46][47][48]. The selectivity of C-dots for ClOˉ detection is evaluated.…”

“…However, the development of C-dots for detection of negative ions is limited. Hypochlorite (ClOˉ) is a powerful oxidant which functions as an antimicrobial agent in water treatment and living organisms [46]. We attempted to use the C-dots as a fluorescent sensing platform for ClOˉ assay.…”

Rapid detection of vegetable cooking oils adulterated with inedible used oil using fluorescence quenching method with aqueous CTAB-coated quantum dots

“…The interdigitated bilayer structure of CTAB-TOPO-coated CdSe/ZnS QD, whose first layer was original surface ligands TOPO and the second layer was CTAB, made it a more sensitive and selective fluorescence probe than CdSe/ZnS QD to the quenchers [46]. Similar organic coated bilayer structures of water-soluble CdSe/ZnS QDs were also investigated by others as fluorescence quenching probes for selective detection and quantification of analytes like chloride anion [47], hypochlorite [48], heavy metal ions [27][28][29][30]49], nitroaromatic [50] and even chiral mixtures of enantiomers [51,52].…”

Preparation of Quantum Dots and Fluorescent Molecularly Imprinted Composite Microspheres for Determination of Tyramine

“…However, the quantum dots used for fluorescence detection often face the problem of coexisting matter interference [4] , especially for the structure and performance similar to the same material detection [5] , the selectivity is not obvious, so the quantum dot fluorescence detection of specific selectivity to be further improved [6] , more for the firm and highly selective construction methods need to be developed [7] . QDs, dissimilar usual organic fluorophores, are composed of inorganic semiconducting materials, such as CdSe, CdS, or ZnS.…”