Ma Weiguang, Wang Lingnan, Zhang Nan, Han Dongxue, Dong Xiandui, Niu Li
†State Key Laboratory of Electroanalytical Chemistry, c/o Engineering Laboratory for Modern Analytical Techniques, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin China.
‡University of Chinese Academy of Sciences, Beijing 100039, China.
Anal Chem. 2015;87(9):4844-50. doi: 10.1021/acs.analchem.5b00315. Epub 2015 Apr 15.
Herein, a novel photoelectrochemical platform with WS2/TiO2 composites as optoelectronic materials was designed for selective detection of o-diphenol and its derivatives without any biomolecule auxiliary. First, catechol was chosen as a model compound for the discrimination from resorcinol and hydroquinone; then several o-diphenol derivatives such as dopamine, caffeic acid, and catechin were also detected by employing this proposed photoelectrochemical sensor. Finally, the mechanism of such a selective detection has been elaborately explored. The excellent selectivity and high sensitivity should be attributed to two aspects: (i) chelate effect of adjacent double oxygen atoms in the o-diphenol with the Ti(IV) surface site to form a five/six-atom ring structure, which is considered as the key point for distinction and selective detection. (ii) This selected WS2/TiO2 composites with proper band level between WS2 and TiO2, which could make the photogenerated electron and hole easily separated and results in great improvement of sensitivity. By employing such a photoelectrochemical platform, practical samples including commercial clinic drugs and human urine samples have been successfully performed for dopamine detection. This biomolecule-free WS2/TiO2 based photoelectrochemical platform demonstrates excellent stability, reproducibility, remarkably convenient, and cost-effective advantages, as well as low detection limit (e.g., 0.32 μmol L(-1) for dopamine). It holds great promise to be applied for detection of o-diphenol kind species in environment and food fields.
在此，设计了一种以WS2/TiO2复合材料为光电子材料的新型光电化学平台，用于选择性检测邻二酚及其衍生物，无需任何生物分子辅助。首先，选择邻苯二酚作为模型化合物，以区分间苯二酚和对苯二酚；然后，利用该光电化学传感器还检测了几种邻二酚衍生物，如多巴胺、咖啡酸和儿茶素。最后，对这种选择性检测的机制进行了深入探讨。优异的选择性和高灵敏度应归因于两个方面：(i)邻二酚中相邻的双氧原子与Ti(IV)表面位点的螯合作用，形成五/六元环结构，这被认为是区分和选择性检测的关键点。(ii)这种选择的WS2/TiO2复合材料在WS2和TiO2之间具有适当的能带水平，这可以使光生电子和空穴容易分离，从而大大提高了灵敏度。通过采用这种光电化学平台，已成功地对包括商业临床药物和人类尿液样本在内的实际样品进行了多巴胺检测。这种基于WS2/TiO2的无生物分子光电化学平台具有优异的稳定性、重现性、显著的便利性和成本效益优势，以及低检测限(例如，多巴胺的检测限为0.32 μmol L(-1))。它在环境和食品领域检测邻二酚类物质方面具有很大的应用前景。
