Department of Chemistry, Faculty of Science, University of Kurdistan, P.O. Box 416, Sanandaj, 66177-15175, Iran.
Chemistry and Chemical Engineering Research Center of Iran, Tehran, 14335-186, Iran.
Mikrochim Acta. 2018 Jul 13;185(8):374. doi: 10.1007/s00604-018-2875-6.
A paper based analytical device is presented for the determination of Cr(III) and Cr(VI) using gold nanoparticles (AuNPs) modified with 2,2'-thiodiacetic acid. The modified AuNPs were characterized using UV-Vis spectrophotometry, Fourier transform infrared, dynamic light scattering, zeta potential, energy dispersive spectroscopy and transmission electron microscopy. Cr(III) ions induce the aggregation of the modified AuNPs, and the color of the nanoprobe changes from red to blue. This can be detected visually, or by colorimetry, or with a camera. No interference is observed in the presence of 19 other cations and anions. Cr(VI) (chromate) can be determined by after reduction to Cr(III) by using ascorbic acid and then quantified total Cr(III). The concentration of Cr(VI) is obtained by subtracting the concentration of Cr(III) from that of total chromium. Under optimal conditions, the ratio of the absorbances measured at 670 (blue) and 522 (red) increases linearly in the 1.0 nM to 22.1 μM chromium concentration range, with 0.66 nM (0.034 ppb) limit of detection (LOD) in solution. In case of the paper device, the linear range extends from 1.0 nM to 0.1 mM, and the LOD is 0.64 nM (0.033 ppb). The method was applied to the determination of chromium in spiked water, urine and dilutes human plasma, and results were confirmed by GF-AAS analysis. This method is highly selective, fast and portable, requires minimum volume of reagents and samples and no washing steps. Graphical abstract A paper based analytical device is presented for determination of Cr(III) and Cr(VI) using gold nanoparticles modified with 2,2'-thiodiacetic acid. In paper optical probe, linear range and limit of detection are 1.0 nM to 0.1 mM and 0.64 nM, respectively. The method was applied to the determination of total chromium in spiked water, urine and dilutes human plasma, and results were confirmed by GF-AAS analysis.
一种基于纸张的分析装置，用于使用 2,2'-硫代二乙酸修饰的金纳米粒子（AuNPs）测定 Cr(III)和 Cr(VI)。修饰后的 AuNPs 采用紫外-可见分光光度法、傅里叶变换红外光谱、动态光散射、Zeta 电位、能量色散光谱和透射电子显微镜进行了表征。Cr(III)离子诱导修饰后的 AuNPs 聚集，纳米探针的颜色从红色变为蓝色。这可以通过肉眼观察、比色法或相机来检测。在存在 19 种其他阳离子和阴离子时，没有观察到干扰。Cr(VI)（铬酸盐）可以通过使用抗坏血酸还原为 Cr(III)后进行定量，然后定量总 Cr(III)。Cr(VI)的浓度通过从总铬浓度中减去 Cr(III)的浓度来获得。在最佳条件下，在 1.0 nM 至 22.1 μM 铬浓度范围内，测量的 670nm（蓝色）和 522nm（红色）处的吸光度之比呈线性增加，溶液中的检出限（LOD）为 0.66 nM（0.034 ppb）。在纸张装置的情况下，线性范围从 1.0 nM 扩展到 0.1 mM，LOD 为 0.64 nM（0.033 ppb）。该方法用于测定加标水中、尿中和稀释人血浆中的铬，并用 GF-AAS 分析进行了验证。该方法具有高选择性、快速和便携的特点，所需试剂和样品量最少，无需洗涤步骤。
