A highly sensitive photoelectrochemical aptamer sensor based on MIL-101(Cr)&Bi2S3 for chlorpyrifos detection

The extensive global application of chlorpyrifos (CPF) has led to significant environmental accumulation through aquatic systems, presenting substantial risks to ecological integrity and public health. This urgency necessitates advanced detection methodologies with enhanced sensitivity and operational efficiency to ensure environmental safety. Here, we developed a novel photoelectrochemical aptamer sensor utilizing a MIL-101(Cr)&Bi 2 S 3 heterostructure composite. This architecture synergistically integrates the broad-spectrum photon absorption capability of Bi 2 S 3 with the hierarchical porosity and structural stability of MIL-101(Cr), achieving remarkable enhancement in both electron-hole separation efficiency and interfacial charge transfer. The sensing platform was further optimized through aptamer functionalization, which confers precise molecular recognition capabilities while maintaining optimal charge transfer dynamics at the electrode interface. Systematic evaluation demonstrated exceptional analytical performance: a linear detection range spanning four orders of magnitude (0.05–10 μg/mL), ultralow detection limit of 0.022 ng/mL (S/N = 3). The developed methodology provides a versatile framework for adapting to other organophosphorus pesticide detection requirements through modular aptamer replacement.