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Enhanced photoelectrochemical sensing based on novel synthesized Bi2S3@Bi2O3 nanosheet heterostructure for ultrasensitive determination of L-cysteine

Wang, Feng Xia, Ye, Cui, Mo, Shi, Luo, Hong Qun, Chen, Jing Rong, Shi, Yan, Li, Nian Bing
Analytical and bioanalytical chemistry 2019 v.411 no.14 pp. 3059-3068
coatings, cysteine, electric current, energy, irradiation, nanosheets, sulfides
The design of a low-cost and highly efficient photoactive heterojunction material for sensing is still a challenging issue. On the basis of the formation of sheet-like Bi₂O₃ via coating Bi₂S₃, a novel Bi₂O₃@Bi₂S₃ heterostructure is controllably synthesized via a facile water bath approach. The prepared Bi₂O₃@Bi₂S₃ nanosheets show a superior photoelectrochemical (PEC) performance for the detection of L-cysteine (L-Cys), and the photocurrent signal is three and four times higher than those of Bi₂S₃ and Bi₂O₃ under visible irradiation, respectively. Also, the heterostructure presents an outstanding linear range for the detection of L-Cys: 0.1–10,000 μM. In addition, the mechanism of improved PEC response of Bi₂O₃@Bi₂S₃ nanosheets is investigated according to the estimated energy band positions. Thus, the integration of the novel heterostructure and the photoelectrochemical technique demonstrates a rapid photocurrent response, showing a great effect on the performance of the sensing system and a new PEC method for highly selective and sensitive chemical detection. Graphical abstract