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

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   ng   mL −1 to 100   ng   mL −1 with a low detection limit of 7.4   pg   mL −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.