Heterostructured CuO-g-C3N4 nanocomposites as a highly efficient photocathode for photoelectrochemical aflatoxin B1 sensing

• Published in: Sensors and actuators. B, Chemical Chemical, 2021-02, Vol.329, p.129146, Article 129146
• Main Authors: Mao, Lebao, Xue, Xiaojie, Xu, Xuan, Wen, Wei, Chen, Miao-Miao, Zhang, Xiuhua, Wang, Shengfu
• Format: Article
• Language: English
• Subjects: Aflatoxin B1; Aflatoxins; Carbon nitride; Copper oxides; CuO-g-C3N4 nanocomposites; Heterojunction; Heterojunctions; Imprinted polymers; Light irradiation; Molecularly imprinted polymer; Nanocomposites; P-n junctions; Photocathodes; Photoelectric effect; Photoelectric emission; Photoelectrochemical sensor; Photosensitivity; Selectivity; Sensors; Target detection
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2020.129146

Construction of CuO-g-C3N4 heterojunction-based MIP-PEC sensors for ultrasensitive detection of aflatoxin B1. [Display omitted] •The heterostructured CuO-g-C3N4 nanocomposites were facilely synthesized by in-situ growth of CuO on g-C3N4 nanosheets.•The prepared CuO-g-C3N4 heterojunction improved separation efficiency of electron-hole pairs and reinfored PEC signal.•Further combining with molecularly imprinting technique, a novel MIP-PEC sensor has been developed for AFB1 detection.•The work offers a detection limit of 6.8 pg mL−1 for AFB1, showing the potential application of PEC sensors in food safety. Here, copper oxide-graphitic carbon nitride (CuO-g-C3N4) nanocomposites were facilely prepared and used as an efficient photosensitive material to construct a highly sensitive photoelectrochemical (PEC) sensor. The CuO-g-C3N4 nanocomposites were directly synthesized by in-situ growth of CuO on g-C3N4 nanosheets to form p-n heterojunction. The optical absorption of CuO-g-C3N4 nanocomposites was efficaciously broadened towards visible region through CuO doping. The heterostructured CuO-g-C3N4 permitted the photogenerated electrons of g-C3N4 to transfer to CuO and meanwhile the photogenerated holes of CuO to migrate to g-C3N4 under visible light irradiation. The effective carriers generation, separation and transfer processes endows CuO-g-C3N4 nanocomposites unique and greatly enhanced cathode photocurrent response as confirmed by a series of PEC studies. Further combining with molecular imprinted polymer (MIP) which acts as a recognition unit, we construct a favorable molecular imprinted polymer photoelectrochemical (MIP-PEC) sensor with high sensitivity for target aflatoxin B1 (AFB1) detection. Under optimal conditions, the proposed MIP-PEC sensor was successfully employed for AFB1 quantitative determination with a linear range of 0.01 ng mL−1 to 1 μg mL−1 and a detection limit of 6.8 pg mL−1. In addition, the sensor has excellent selectivity under high concentrations of interfering substances circumstance. The satisfactory AFB1 recoveries in maize solution illustrated the credible application of the proposed MIP-PEC sensors for real samples, indicating promising potential in food safety control.