Analytical Chemistry Laboratory, Faculty of Chemistry, University of Guilan, Namjoo Street, P.O. Box 1914, Rasht, Iran.
Analytical Chemistry Laboratory, Faculty of Chemistry, University of Guilan, Namjoo Street, P.O. Box 1914, Rasht, Iran.
Biosens Bioelectron. 2017 Oct 15;96:324-331. doi: 10.1016/j.bios.2017.05.028. Epub 2017 May 12.
With the advantages of excellent optical properties and biocompatibility, single-strand DNA-functionalized quantum dots have been widely applied in biosensing and bioimaging. A new aptasensor with easy operation, high sensitivity, and high selectivity was developed by immobilizing the aptamer on water soluble l-cysteine capped ZnS quantum dots (QDs). Graphene oxide (GO) sheets are mixed with the aptamer-QDs. Consequently, the aptamer-conjugated QDs bind to the GO sheets to form a GO/aptamer-QDs ensemble. This aptasensor enables the energy transfer based on a fluorescence resonance energy transfer (FRET) from the QDs to the GO sheets, quenching the fluorescence of QDs. The GO/aptamer-QDs ensemble assay acts as a "turn-on'' fluorescent sensor for edifenphos (EDI) detection. When GO was replaced by EDI, the fluorescence of QDs was restored and its intensity was proportional to the EDI concentration. This GO-based aptasensor under the optimum conditions exhibited excellent analytical performance for EDI determination, ranging from 5×10 to 6×10mg L with the detection limit of 1.3×10mgL. Furthermore, the designed aptasensor exhibited excellent selectivity toward EDI compared to other pesticides and herbicides with similar structures such as diazinon, heptachlor, endrin, dieldrin, butachlor and chlordane. Good reproducibility and precision (RSD =3.9%, n =10) of the assay indicates the high potential of the aptasensor for quantitative trace analysis of EDI. Moreover, the results demonstrate the applicability of the aptasensor for monitoring EDI fungicide in spiked real samples.
具有优异光学性能和生物相容性的单链 DNA 功能化量子点已广泛应用于生物传感和生物成像。通过将适配体固定在水溶性半胱氨酸封端的 ZnS 量子点 (QDs) 上，开发了一种具有操作简单、灵敏度高和选择性高的新型适配体传感器。氧化石墨烯 (GO) 片与适配体-QDs 混合。因此，适配体偶联的 QDs 与 GO 片结合形成 GO/适配体-QDs 组装体。这种适配体传感器能够基于从 QDs 到 GO 片的荧光共振能量转移 (FRET) 实现能量转移，从而猝灭 QDs 的荧光。GO/适配体-QDs 组装体分析物作为一种用于检测敌敌畏 (EDI) 的“开启”荧光传感器。当 GO 被 EDI 取代时，QDs 的荧光得到恢复，其强度与 EDI 浓度成正比。在最佳条件下，这种基于 GO 的适配体传感器对 EDI 的测定表现出优异的分析性能，其范围从 5×10 到 6×10mg L，检测限为 1.3×10mgL。此外，与具有类似结构的其他杀虫剂和除草剂（如敌百虫、七氯、艾氏剂、狄氏剂、丁草胺和氯丹）相比，该设计的适配体传感器对 EDI 表现出优异的选择性。良好的重现性和精密度（RSD=3.9%，n=10）表明该传感器具有用于 EDI 痕量分析的高潜力。此外，结果表明该适配体传感器适用于监测加标真实样品中的 EDI 杀菌剂。
