Liu Dingmin, Huang Pengcheng, Wu Fang-Ying
School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, China.
Anal Methods. 2022 May 13;14(18):1803-1809. doi: 10.1039/d2ay00368f.
A colorimetric assay was described for determination of tetracyclines (TCs) in complex matrices based on dual regulation of gold nanoparticle (AuNP) aggregation and silver metallization. The reaction between -aminophenol and silver ions (Ag) catalyzed by aptamer (Apt)-functionalized AuNPs promoted the deposition of Ag shells on AuNPs to afford core-shell bimetallic NPs (Au@AgNPs). When the target is present, Apt is separated from the AuNP surface through the Apt-target interaction. With the desorption of Apts, AuNPs catalyzed the formation of more aggregated Au@AgNPs with a thinner Ag shell, corresponding to the solution color gradually changing from orange-yellow to brown. Using / as the determination signal, the assay gave visible linear relationships for TCs in the range of 0.3-6.0 μmol L with a detection limit (LOD) of 33.6 nmol L. In particular, the assay was successfully applied to detect TCs in real samples with the recovery rate ranging from 91.2% to 106% and relative standard deviation (RSD) less than 4.6%. These results meet the requirements of sample analysis.
描述了一种基于金纳米颗粒（AuNP）聚集和银金属化双重调控的比色法，用于测定复杂基质中的四环素（TC）。适配体（Apt）功能化的AuNPs催化对氨基苯酚与银离子（Ag）之间的反应，促进了Ag壳层在AuNPs上的沉积，从而得到核壳双金属纳米颗粒（Au@AgNPs）。当存在靶标时，Apt通过Apt-靶标相互作用从AuNP表面分离。随着Apt的解吸，AuNPs催化形成更多聚集的、Ag壳层更薄的Au@AgNPs，对应溶液颜色从橙黄色逐渐变为棕色。以/作为测定信号，该方法对TCs在0.3 - 6.0 μmol/L范围内呈现出明显的线性关系，检测限（LOD）为33.6 nmol/L。特别地，该方法成功应用于实际样品中TCs的检测，回收率在91.2%至106%之间，相对标准偏差（RSD）小于4.6%。这些结果满足样品分析的要求。
