Teeparuksapun Kosin, Prasongchan Nicha, Thawonsuwan Auttachai
Science Program, Department of General Education, Faculty of Liberal Arts, Rajamangala University of Technology Srivijaya.
Anal Sci. 2019 Apr 10;35(4):371-377. doi: 10.2116/analsci.18P442. Epub 2018 Nov 30.
A facile, low cost, rapid and easy-to-use colorimetric sensor for the detection of Cu ion is described using alpha-lipoic acid (ALA) functionalized AgNPs. The prepared ALA-AgNPs are yellow, and spherical with an average particle size of 9.23 ± 3.36 nm. The addition of Cu ion resulted in the aggregation of ALA-AgNP solution and caused a visible color change from yellow to orange-brown, which could be detected by the naked eye and UV-vis spectrophotometer. Parameters affecting the sensitivity of the sensor were investigated, including ALA concentrations, reaction times, reaction volumes and pH. Under optimal conditions, the colorimetric sensor could detect Cu ion in the range of 0.625 × 10 to 10 × 10 M with a linear coefficient (r) of 0.9978. The limit of detection (LOD) and limit of quantification (LOQ) were 0.43 × 10 M (4.3 μM) and 1.45 × 10 M (14.5 μM), respectively, which is lower than the limit set by the U.S. Environmental Protection Agency (EPA). This proposed method showed good selectivity and could detect Cu within 5 min. Finally, the proposed method could be successfully applied for the analysis of Cu ion in tap water samples.
描述了一种使用α-硫辛酸（ALA）功能化的银纳米颗粒（AgNPs）制备的用于检测铜离子的简便、低成本、快速且易于使用的比色传感器。制备的ALA-AgNPs呈黄色，为球形，平均粒径为9.23±3.36nm。铜离子的加入导致ALA-AgNP溶液聚集，并引起从黄色到橙棕色的明显颜色变化，这可以通过肉眼和紫外可见分光光度计检测到。研究了影响传感器灵敏度的参数，包括ALA浓度、反应时间、反应体积和pH值。在最佳条件下，比色传感器能够检测0.625×10至10×10M范围内的铜离子，线性系数（r）为0.9978。检测限（LOD）和定量限（LOQ）分别为0.43×10M（4.3μM）和1.45×10M（14.5μM），低于美国环境保护局（EPA）设定的限值。该方法具有良好的选择性，可在5分钟内检测到铜离子。最后，该方法可成功应用于自来水样品中铜离子的分析。
