Integrated Photoelectrochemical-Fluorescence Dual-Mode Aptasensor for Sensitive Detection of Fumonisin B1

Long-term intake of fumonisin B1 (FB1) can pose a threat to human health. It is essential to develop an accurate and sensitive method to detect FB1. In this work, a photoelectrochemical-fluorescence (PEC-FL) dual-mode aptamer sensing platform was proposed for FB1 analysis. Tb@Zr-MOF was used as a dual-functional signal label connected to p-DNA, which not only emits a fluorescent signal but also utilizes its low conductivity and steric hindrance effect to quench photocurrent and achieve signal amplification. Furthermore, BiOI/CuBi₂O₄, with a high electrode active surface area was served as a sensing matrix to provide more active sites for DNA loading. The Z-scheme heterojunction formed between BiOI and CuBi₂O₄ significantly enhanced the electron transfer rate. The sensing platform exhibited a wide linear detection range in both PEC (100 fg/mL-1 μg/mL) and FL (100 fg/mL-1 μg/mL) modes, with detection limits as low as 17.78 fg/mL (S/N = 3) and 21.93 fg/mL (S/N = 3), respectively. This work avoids environmental and operation-induced errors in single-mode detection through dual-mode cross-validation, providing a good application prospect for reliable and accurate analysis of FB1.