College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China.
College of Geology and Environment, Xi'an University of Science and Technology, Xi'an 710054, China.
Sci Total Environ. 2021 Apr 20;766:142579. doi: 10.1016/j.scitotenv.2020.142579. Epub 2020 Oct 6.
A colorimetric sensor for detection of Hg is developed via graphene oxide/gold nanoparticles (GO/AuNPs) nanocomposite as peroxidase mimic. In the absence of Hg, the adsorption of ss-DNA on GO/AuNPs resulted in the decrease of peroxidase-like activity of GO/AuNPs, which catalyzed the oxidation of 3, 3, 5, 5-tetramethylbenzidine (TMB) to be very light blue. In the presence of Hg, the oligonucleotides of T-Hg-T conformation formed by thymine-Hg(II)-thymine interaction could not be adsorbed or bonded on GO/AuNPs, and the GO/AuNPs resumed their original high activity of peroxidase mimic and catalyzed the oxidation of TMB into distinct blue product. Under optimized conditions, the absorbance value at the wavelength of 655 nm (A) was linearly related with the concentration of Hg in the range between 5.2 × 10 M and 1.2 × 10 M with a detection limit of 3.8 × 10 M. By visual observation with the naked eye, Hg as low as 3.3 × 10 M could cause color change in solution. The specific T-Hg-T binding made it easy to selectively detect Hg. The results show that the colorimetric assay offers great potential for the detection of Hg in real samples.
一种基于氧化石墨烯/金纳米粒子（GO/AuNPs）纳米复合材料的比色传感器被开发用于检测 Hg。在没有 Hg 的情况下，ss-DNA 吸附在 GO/AuNPs 上导致 GO/AuNPs 的过氧化物酶样活性降低，GO/AuNPs 催化 3,3,5,5-四甲基联苯胺（TMB）的氧化生成非常浅的蓝色。在存在 Hg 的情况下，胸腺嘧啶-Hg(II)-胸腺嘧啶相互作用形成的 T-Hg-T 构象的寡核苷酸不能被吸附或键合在 GO/AuNPs 上，GO/AuNPs 恢复其原有的过氧化物酶样高活性，并催化 TMB 氧化生成明显的蓝色产物。在优化条件下，在 655nm 处的吸光度值（A）与 Hg 浓度在 5.2×10-7 M 至 1.2×10-5 M 范围内呈线性关系，检测限为 3.8×10-7 M。通过肉眼观察，溶液中低至 3.3×10-7 M 的 Hg 就能引起溶液颜色变化。特定的 T-Hg-T 结合使其易于选择性地检测 Hg。结果表明，比色测定法在实际样品中检测 Hg 具有很大的潜力。
