Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, 5166616471, Iran.
Anal Sci. 2023 Jul;39(7):1107-1114. doi: 10.1007/s44211-023-00320-w. Epub 2023 Mar 29.
In this study, a simple and sensitive colorimetric method for penconazole sensing is reported. It is based on the etching/anti-etching strategy in which gold nanostar@graphene quantum dot (AuNS@GQD) nanocomposite acts as a sensing nanoprobe and IO as an etching agent. With adding IO to the solution of AuNSs@GQDs, the sharp tips of NSs are etched and they are transformed into nearly spherical nanostructures, and the color of the solution changes from green to violet. These changes can be attributed to the oxidation of gold atoms at the sharp corners and tips of NSs with I, produced by the reaction of IO with AuNS@GQD solution. When penconazole is added into the system, the color and shape variations of AuNSs caused by periodate are impressively prevented. It can be assigned to the strong binding affinity between nitrogen atoms of penconazole and gold atoms, which protects them from etching by I. This mechanism has been affirmed via transmission electron microscopy (TEM) and UV-Vis spectra. This approach exhibited a good linear relationship (R = 0.999) between the wavelength shift and penconazole concentration in the range of 5.0-1000.0 nM with a limit of detection (LOD) of 1.5 nM. The sensor is stable and reproducible and was used to measure penconazole in spiked water samples with recoveries over 97%.
在这项研究中，报道了一种用于烯唑醇传感的简单灵敏的比色法。它基于刻蚀/反刻蚀策略，其中金纳米星@graphene 量子点（AuNS@GQD）纳米复合材料作为传感探针，IO 作为刻蚀剂。向 AuNSs@GQDs 的溶液中加入 IO 后，NSs 的尖锐尖端被刻蚀，它们转变为几乎球形的纳米结构，溶液的颜色从绿色变为紫色。这些变化归因于 IO 与 AuNS@GQD 溶液反应产生的 I 对 NSs 尖锐角落和尖端处的金原子的氧化。当加入烯唑醇到体系中时，高碘酸盐引起的 AuNSs 的颜色和形状变化得到显著阻止。这可以归因于烯唑醇中的氮原子与金原子之间的强结合亲和力，这保护它们免受 I 的刻蚀。该机制已通过透射电子显微镜（TEM）和 UV-Vis 光谱得到证实。该方法在 5.0-1000.0 nM 的范围内表现出与烯唑醇浓度之间良好的线性关系（R=0.999），检测限（LOD）为 1.5 nM。传感器稳定且可重现，并用于测定加标水样中的烯唑醇，回收率超过 97%。
