Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering , Northwest Normal University , Lanzhou 730070 , People's Republic of China.
Tianjin Key Laboratory of Molecular Optoelectronic Science, Department of Chemistry, School of Science , Tianjin University , Tianjin , 300072 , People's Republic of China.
Anal Chem. 2019 Mar 19;91(6):4031-4038. doi: 10.1021/acs.analchem.8b05472. Epub 2019 Mar 6.
In this work, we discover an effective domino-effect-based detection mechanism for the rapid, high-selectivity, and ultrasensitive naked-eye colorimetric ratio assay of chromium(III) ion (Cr) in aqueous solutions. This naked-eye colorimetric ratio assay to Cr relies on changes in absorbance properties that are due to the stimuli response of Cr for the morphological transformation of silver nanoflakes. In the presence of Cr, large silver nanoflakes can be stimulated to transform to small nanoparticles (NPs), which promoted a color change in solution from bright yellow to wine red that was detected by the naked eye and spectroscopic absorption methods. The proposed naked-eye sensing strategy was coupled with an ultraviolet (UV)-spectroscopic chemosensor for the detection of trace Cr. The detection method showed an ultralow detection limit of 1.4 nM (nanomole) for Cr in ultrapure water and 11.5 nM in human serum sample, respectively. On the basis of colorimetry, the lowest concentration of ∼50 nM for Cr in ultrapure water and human serum can be detected by the naked eye. This naked-eye-based colorimetric ratio assay for accurate and selective identification and high sensitivity of Cr is expected to have large potential and wide applications such as pharmaceutical analysis, clinical diagnosis, and environmental monitoring.
在这项工作中，我们发现了一种基于级联效应的有效检测机制，用于快速、高选择性和超灵敏的水溶液中三价铬（Cr）的裸眼比色分析。这种 Cr 的裸眼比色分析依赖于吸光度特性的变化，这是由于 Cr 的刺激响应导致银纳米薄片的形态转变。在存在 Cr 的情况下，大的银纳米薄片可以被刺激转化为小的纳米颗粒（NPs），这促进了溶液颜色从亮黄色到酒红色的变化，通过肉眼和光谱吸收方法可以检测到。所提出的裸眼传感策略与紫外（UV）光谱化学传感器结合，用于检测痕量 Cr。该检测方法在超纯水中对 Cr 的检测限低至 1.4 nM（毫摩尔），在人血清样本中为 11.5 nM。基于比色法，在超纯水中和人血清中可以用肉眼检测到约 50 nM 的 Cr。这种基于裸眼的比色比率分析方法对 Cr 的准确和选择性识别以及高灵敏度具有很大的潜力和广泛的应用，如药物分析、临床诊断和环境监测。
