Tharmaraj Vairaperumal, Yang Jyisy
Department of Chemistry, National Chung-Hsing University, 250 Kuo-Kuang Rd, Taichung 402, Taiwan.
Analyst. 2014 Dec 7;139(23):6304-9. doi: 10.1039/c4an01449a. Epub 2014 Oct 15.
A simple and effective colorimetric method for determination of Cu(2+) in real samples was developed. In this method, thiomalic acid functionalized silver nanoparticles (TMA-AgNPs) were prepared and changes in solution color, induced by the aggregation of TMA-AgNPs in the presence of Cu(2+), were employed for quantitative analysis. The surface plasmon resonance (SPR) band of our synthesized TMA-AgNPs was located at 392 nm and shifted to a longer wavelength after aggregation due to the interactions between carboxylate and Cu(2+). A band intensity ratio of A455/(A392-A455) was constructed and used to correlate with the concentration of Cu(2+). A linear relationship was found with a linear response up to 50 nM of Cu(2+). Due to the formation of a stable carboxylate Cu(2+) complex, highly sensitive detection of Cu(2+) was achieved with the estimated detection limit approaching 1 nM. Moreover, the formation of the stable complex leads to high selectivity in the detection of Cu(2+), which was verified by examination of 12 other metal ions. In the detection of Cu(2+) in real samples, results indicated that our proposed method is simple, sensitive and selective for application in such measurements.
开发了一种用于测定实际样品中Cu(2+)的简单有效的比色法。在该方法中，制备了硫代苹果酸功能化的银纳米颗粒（TMA-AgNPs），并利用在Cu(2+)存在下TMA-AgNPs聚集引起的溶液颜色变化进行定量分析。我们合成的TMA-AgNPs的表面等离子体共振（SPR）带位于392nm处，聚集后由于羧酸盐与Cu(2+)之间的相互作用而向更长波长移动。构建了A455/(A392-A455)的带强度比，并用于与Cu(2+)的浓度相关联。发现线性关系，Cu(2+)的线性响应高达50 nM。由于形成了稳定的羧酸盐Cu(2+)络合物，实现了对Cu(2+)的高灵敏度检测，估计检测限接近1 nM。此外，稳定络合物的形成导致对Cu(2+)检测的高选择性，这通过对其他12种金属离子的检测得到验证。在实际样品中Cu(2+)的检测中，结果表明我们提出的方法简单、灵敏且具有选择性，适用于此类测量。
