Department of Chemistry, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
Applied Analytical Chemistry Research Unit, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand.
Molecules. 2020 Sep 27;25(19):4443. doi: 10.3390/molecules25194443.
A new colorimetric sensor based on gold/silver bimetallic nanoparticles (Au-Ag BNPs) for the sensitive and selective detection of mercury (II) was developed. Gold nanoparticles (AuNPs) were synthesized by Turkevich method. The surface modification of AuNPs was modified by the layer-by-layer technique using poly(diallyl dimethylammonium chloride) which provided positively charged of AuNPs. Negatively charged silver nanoparticles (AgNPs) were synthesized by chemical reduction using poly(4-styrenesulfonic acid-co-maleic acid) as the stabilizing agent. The layer-by-layer assembly deposition technique was used to prepare Au-Ag BNPs of positively and negatively charged of AuNPs and AgNPs, respectively. The synthesized Au-Ag BNPs were characterized by a UV-visible spectrophotometer, zeta potential analyzer, FT-IR, TEM, XRD, and EDX. The Au-Ag BNPs sensor was able to detect mercury (II) in aqueous solution, visibly changing from brownish-orange to purple. The linear relationships of the UV-visible spectrometry demonstrate that the Au-Ag BNPs-based colorimetric sensor can be used for the quantitative analysis of mercury (II) in the range of 0.5-80 mg L, with the correlation coefficient, r = 0.9818. The limit of detection (LOD) of mercury (II) was found to be 0.526 + 0.001 mg L. The BNPs is also verified to have a good practical applicability for mercury (II) detection in the real samples.
一种基于金银双金属纳米粒子（Au-Ag BNPs）的新型比色传感器被开发出来，用于灵敏和选择性地检测汞（II）。金纳米粒子（AuNPs）通过 Turkevich 法合成。AuNPs 的表面修饰通过层层技术用聚（二烯丙基二甲基氯化铵）进行，该技术为 AuNPs 提供了正电荷。负电荷的银纳米粒子（AgNPs）通过使用聚（4-苯乙烯磺酸-co-马来酸）作为稳定剂的化学还原法合成。层层组装沉积技术用于制备带正电荷和负电荷的 AuNPs 和 AgNPs 的 Au-Ag BNPs。合成的 Au-Ag BNPs 通过紫外可见分光光度计、zeta 电位分析仪、FT-IR、TEM、XRD 和 EDX 进行表征。Au-Ag BNPs 传感器能够检测水溶液中的汞（II），颜色从棕橙色变为紫色。紫外可见光谱的线性关系表明，基于 Au-Ag BNPs 的比色传感器可用于在 0.5-80mg/L 范围内对汞（II）进行定量分析，相关系数 r = 0.9818。汞（II）的检测限（LOD）被发现为 0.526 ± 0.001mg/L。BNPs 还被证明在实际样品中检测汞（II）具有良好的实际适用性。
