College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
Department of Chemistry, Brown University, Providence, RI, 02912, USA.
Mikrochim Acta. 2019 Feb 15;186(3):186. doi: 10.1007/s00604-019-3293-0.
Etched PtCu nanowires (NWs) were synthesized by a hydrothermal reaction and chemical etching process. The NWs are shown to be viable peroxidase (POx) mimics capable of catalyzing the oxidation of the substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of HO to form a blue-green coloration. The mechanism of catalysis was investigated and the results demonstrated that HO is decomposed to form hydroxyl radicals which oxidize TMB in the presence of the NWs. Under optimized conditions, a steady-state kinetic analysis revealed that the NWs possess a stronger affinity for HO and TMB compared to the enzyme horseradish POx. Based on the high POx-like activity, a colorimetric assay for HO was established. Absorbance at 652 nm increases linearly in the 0.1-300 μM HO concentration range, and the detection limit is 0.06 μM (at S/N = 3). The assay was successfully applied to the determination of HO in (spiked) milk and contact lens solution. Furthermore, a highly sensitive test strip was designed which represents a low cost and fast alternative for the visual determination of HO. Graphical Abstract Schematic presentation of the colorimetric detection of HO. PtCu nanowires (PtCu NWs) can catalyze 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by HO to produce blue-green oxidized 3,3',5,5'-tetramethylbenzidine (oxTMB). Based on the color change, test strips were designed for HO detection.
刻蚀的 PtCu 纳米线（NWs）通过水热反应和化学刻蚀工艺合成。这些 NWs 被证明是可行的过氧化物酶（POx）模拟物，能够在 HO 的存在下催化底物 3,3',5,5'-四甲基联苯胺（TMB）的氧化，形成蓝绿色着色。对催化机制进行了研究，结果表明 HO 分解形成羟基自由基，在 NWs 的存在下氧化 TMB。在优化条件下，稳态动力学分析表明，与酶辣根过氧化物酶（HRP）相比，NWs 对 HO 和 TMB 具有更强的亲和力。基于高的 POx 样活性，建立了用于 HO 的比色测定法。在 0.1-300 μM HO 浓度范围内，652nm 处的吸光度呈线性增加，检测限为 0.06 μM（S/N = 3）。该测定法成功应用于（加标）牛奶和隐形眼镜溶液中 HO 的测定。此外，设计了一种高灵敏度的测试条，代表了用于 HO 可视化测定的低成本和快速替代方法。摘要图 用于 HO 比色检测的示意图。PtCu 纳米线（PtCu NWs）可以催化 HO 氧化 3,3',5,5'-四甲基联苯胺（TMB），生成蓝绿色的氧化 3,3',5,5'-四甲基联苯胺（oxTMB）。基于颜色变化，设计了用于 HO 检测的测试条。
