Wang Panpan, Cao Ling, Wu Ying, Di Junwei
College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou, 215123, People's Republic of China.
Mikrochim Acta. 2018 Jul 4;185(7):356. doi: 10.1007/s00604-018-2883-6.
Under visible-light irradiation, a cathodic photoelectrochemical (PEC) sensor is presented for highly sensitive determination of Cr(VI) at a potential of -0.25 V (vs SCE). PbS quantum dots (QDs) were capped with mercaptoacetic acid and assembled on the surface of an indium tin oxide (ITO) electrode via the linker poly(diallyl dimethyl ammonium chloride) providing a photoactive sensor. Cr(VI) accepts the photoelectrons generated by the PbS QDs. This promotes the separation of electron holes and enhances the cathodic photocurrent generated by a 470-nm LED. The sensor has 10 pM detection limit and a linear working range from 0.02 nM to 2 μM of chromate. The method was successfully applied to the determination of Cr(VI) and total chromium in spiked environmental water samples. Graphical abstract Schematic illustration of the photocurrent enhancement response of ITO/PbS toward chromium(VI). In the presence of Cr(VI) (red line), Cr(VI) accepts the photoelectrons generated by the PbS QDs under 470-nm LED irradiation, resulting in improved photocurrent of ITO/PbS.
在可见光照射下，提出了一种阴极光电化学（PEC）传感器，用于在-0.25 V（相对于饱和甘汞电极）的电位下高灵敏度测定Cr(VI)。硫化铅量子点（QDs）用巯基乙酸封端，并通过连接剂聚二烯丙基二甲基氯化铵组装在氧化铟锡（ITO）电极表面，从而提供一种光活性传感器。Cr(VI)接受由硫化铅量子点产生的光电子。这促进了电子空穴的分离，并增强了由470 nm发光二极管产生的阴极光电流。该传感器的检测限为10 pM，铬酸盐的线性工作范围为0.02 nM至2 μM。该方法成功应用于加标环境水样中Cr(VI)和总铬的测定。图形摘要 ITO/PbS对铬(VI)的光电流增强响应示意图。在Cr(VI)存在下（红线），Cr(VI)在470 nm发光二极管照射下接受由硫化铅量子点产生的光电子，导致ITO/PbS的光电流提高。
