College of Chemistry, Liaoning University, Shenyang 110036, China.
College of Physics, Liaoning University, Shenyang 110036, China.
Sci Total Environ. 2022 Jul 15;830:154598. doi: 10.1016/j.scitotenv.2022.154598. Epub 2022 Mar 18.
Hexavalent chromium (Cr(VI)) pollution in the water system has seriously endangered human health and the environment. Herein, we propose a rapid, simple and sensitive surface-enhanced resonance Raman scattering (SERRS) sensor with the bifunctional negatively charged gold nanoparticles ((-)AuNPs) which employ as not only the oxidoreductase-like nanozyme but also the substrate to determine Cr(VI). (-)AuNPs effectively promoted the conversion of 3,3',5,5'-tetramethylbenzidine (TMB) into the blue product of 3,3',5,5'-tetramethylbenzidine diamine (oxTMB) in the presence of Cr(VI) and generated a strong SERRS signal at 1611 cm. According to this principle, the Raman intensity difference at 1611 cm exhibited a satisfactory linear relationship with the logarithm of the Cr(VI) concentration from 10 to 10 M with a low limit of detection (LOD) of 0.4 nM. In addition, the possible SERRS enhancement mechanism, selectivity and reproducibility were also investigated. What's more, the SERRS platform was successfully applied in the complicated water samples, which was anticipated to become a promising analytical method for monitoring of Cr(VI) in the environment.
六价铬（Cr(VI)）在水系中的污染严重威胁着人类健康和环境。在此，我们提出了一种快速、简单、灵敏的表面增强共振拉曼散射（SERRS）传感器，该传感器使用带负电荷的金纳米粒子（(-)AuNPs）作为氧化还原酶样纳米酶，同时作为基底来测定 Cr(VI)。(-)AuNPs 有效地促进了在 Cr(VI)存在的情况下，3,3',5,5'-四甲基联苯胺（TMB）转化为 3,3',5,5'-四甲基联苯二胺（oxTMB）的蓝色产物，并在 1611cm 处产生了强烈的 SERRS 信号。根据这一原理，在 1611cm 处的 Raman 强度差与 Cr(VI)浓度的对数在 10 到 10 M 之间呈现出令人满意的线性关系，检测限（LOD）低至 0.4 nM。此外，还研究了可能的 SERRS 增强机制、选择性和重现性。更重要的是，该 SERRS 平台成功应用于复杂水样中，有望成为环境中 Cr(VI)监测的一种有前途的分析方法。
