Photoelectrochemical sensor based on molecularly imprinted film modified hierarchical branched titanium dioxide nanorods for chlorpyrifos detection

摘要

A photoelectrochemical (PEC) sensor based on hierarchical branched titanium dioxide nanorods (B-TiO_2 NRs) modified with molecularly imprinted polymer (MIP) was constructed for sensitive and efficient detection of chlorpyris (CPF). B-TiO_2 NRs were grown directly on fluorine doped tin oxide substrate by the hydrothermal method and employed as matrix for immobilization of MIP. P-aminothiophenol (ATP) and CPF were assembled on the surface of B-TiO_2 NRs by formation of hydrogen-bonding interactions through electropolymerization in the MIP preparation process. The MIP was characterized by scanning electron microscopy, and further confirmed by cyclic voltammetry to prove the successful synthesis. In the proposed sensing platform, the photocurrent response is inversely proportional to the CPF concentration because the insulating layer hinders the harvesting of light and electron transfer with increasing of CPF concentration. Moreover, the MIP based B-TiO_2 NRs (MIP-B-TiO_2 NRs) had an excellent recognition capacity for specific detection CPF over other pesticides. The PEC sensing platform is developed for the detection of CPF in the linear range from 0.01 ngmL~(-1) to 100 ngmL~(-1) with a low detection limit of 7.4 pgmL~(-1). The proposed sensor offered a promising platform for application in detecting pesticide residuals and other environment deleterious chemicals with excellent sensitivity and selectivity, low interference and high stability.