School of Materials Science and Technology , Nanjing University of Aeronautics and Astronautics , Nanjing 211106 , China.
State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China.
Anal Chem. 2018 Apr 17;90(8):5439-5444. doi: 10.1021/acs.analchem.8b00742. Epub 2018 Apr 5.
This work reports the synthesis, characterization, and application of bifunctional semiconducting CuO nanotubes (NTs) electrode for innovative synergized cathodic photoelectrochemical (PEC) enzymatic bioanalysis. Specifically, CuO NTs electrode was fabricated by surface oxidation of the copper foil in an alkaline aqueous solution with (NH)SO and then annealed in air at 200 °C. After the subsequent coupling with the model enzyme of xanthine oxidase (XOD), the resulted photocathodic enzyme biosensor exhibited good analytical performance of rapid response, high stability, and good sensitivity. Especially, due to the unique catalytic property of CuO toward HO, a novel enzymatic cascade design between biological catalyst (XOD as natural enzyme) and biomimetic catalyst (CuO as the peroxidase mimetics) was constructed, and the dual-catalyst system with special synergy effect could achieve the cathodic PEC guanine bioanalysis with enhanced efficiency. In the determination, the cathodic photocurrent was found to be proportional to the guanine concentration, which was different from the commonly observed O-dependent suppression of the photocurrent. In all, such a bifunctional CuO NTs-based PEC bioassay format has not been reported. The success of this work can offer great chances for further development and implementation of novel CuO-based PEC bioanalytical systems. More importantly, the strategy proposed here could contribute to the development of an original prototype for general PEC enzymatic bioanalysis.
这项工作报道了多功能半导体氧化铜纳米管（NTs）电极的合成、表征及其在协同阴极光电化学（PEC）酶生物分析中的应用。具体来说，通过在碱性水溶液中用（NH4）2SO4对铜箔进行表面氧化，然后在 200°C 的空气中退火，制备了 CuO NTs 电极。随后与黄嘌呤氧化酶（XOD）的模型酶偶联后，所得光阴极酶生物传感器表现出快速响应、高稳定性和良好灵敏度的分析性能。特别是，由于 CuO 对 HO 的独特催化特性，构建了一种新颖的酶级联设计，将生物催化剂（XOD 作为天然酶）和仿生催化剂（CuO 作为过氧化物酶模拟物）结合在一起，该双催化剂体系具有特殊的协同效应，可实现增强效率的阴极 PEC 鸟嘌呤生物分析。在测定中，发现阴极光电流与鸟嘌呤浓度成正比，这与通常观察到的光电流依赖 O 的抑制作用不同。总之，这种基于双功能 CuO NTs 的 PEC 生物分析格式尚未见报道。这项工作的成功为进一步开发和实施新型基于 CuO 的 PEC 生物分析系统提供了巨大的机会。更重要的是，这里提出的策略可以为一般 PEC 酶生物分析的原始原型的发展做出贡献。
