Wang Hao, Zhang Bihong, Zhao Faqiong, Zeng Baizhao
Key Laboratory of Analytical Chemistry for Biology and Medicine, College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , P. R. China.
ACS Appl Mater Interfaces. 2018 Oct 17;10(41):35281-35288. doi: 10.1021/acsami.8b12979. Epub 2018 Oct 4.
A Z-scheme I-BiOCl/N-GQD (i.e., nitrogen-doped graphene quantum dot) heterojunction was prepared by a one-pot precipitation method at room temperature. The doped iodine decreased the band gap of BiOCl, the introduced N-GQDs enhanced light harvesting and prolonged the photogenerated electron lifetime, and the resultant Z-scheme heterojunction promoted the spatial separation of interfacial charges. Thus, the composite showed high photoelectrochemical activity and a big cathodic photocurrent signal. On the basis of the coordination of chlorpyrifos with surface Bi(III) of the composite, a cathodic photoelectrochemical sensor was constructed for the selective detection of chlorpyrifos. In this case, chlorpyrifos decreased the lifetime of photogenerated electrons, so the photocurrent became small. Furthermore, the photocurrent changed and the logarithm of chlorpyrifos concentration presented a linear relationship. The linear range was 0.3-80 ng mL, and the limit of detection was estimated to be 0.01 ng mL (defined as S/N = 3). The present strategy can also be used for the design and fabrication of other PEC sensors suitable for different analytes.
通过室温下单步沉淀法制备了Z型I-BiOCl/N-GQD（即氮掺杂石墨烯量子点）异质结。掺杂的碘降低了BiOCl的带隙，引入的N-GQDs增强了光捕获并延长了光生电子寿命，所得的Z型异质结促进了界面电荷的空间分离。因此，该复合材料表现出高光电化学活性和大的阴极光电流信号。基于毒死蜱与复合材料表面Bi(III)的配位作用，构建了用于选择性检测毒死蜱的阴极光电化学传感器。在这种情况下，毒死蜱缩短了光生电子寿命，因此光电流变小。此外，光电流发生变化，且毒死蜱浓度的对数呈现线性关系。线性范围为0.3-80 ng mL，检测限估计为0.01 ng mL（定义为S/N = 3）。本策略还可用于设计和制造适用于不同分析物的其他PEC传感器。
