Label-free photoelectrochemical immunosensor for aflatoxin B1 detection based on the Z-scheme heterojunction of g-C3N4/Au/WO3
2021
Pei, Fubin | Feng, Shasha | Wu, Yi | Lv, Xuchu | Wang, Hualai | Chen, Shen-Ming | Hao, Qingli | Cao, Yang | Lei, Wu | Tong, Zhaoyang
Aflatoxin B1 (AFB1) is the most toxic mycotoxin, is widely found in foods and animal feeds, and can pose a serious threat to our lives. A label-free photoelectrochemical (PEC) immunosensor was fabricated for the sensitive detection of AFB1. A Z-scheme heterojunction of gold nanoparticles (Au NPs) loaded on graphitic carbon nitride sheet and tungsten trioxide sphere composite (g-C₃N₄/Au/WO₃) acted as the highly sensitive platform. The g-C₃N₄/Au/WO₃ is capable, not only of immobilizing antibodies via Au NPs, but also enhancing the separation of electron-hole pairs due to its good energy band matching efficiency. The mechanism of photo-generated electron/hole transfer on g-C₃N₄/Au/WO₃ was explored using scavengers to eliminate active components. On this basis, an electron transfer pathway for the immunosensor was deduced. The PEC immunosensor displayed a linear concentration range from 1.0 pg mL⁻¹ to 100 ng mL⁻¹ and a low detection limit of 0.33 pg mL⁻¹ (S/N = 3) for AFB1. Good reproducibility, stability, and specificity provide a solid foundation for the practical application of this immunosensor.
显示更多 [+] 显示较少 [-]