Au/TiO₂-based molecularly imprinted photoelectrochemical sensor for dibutyl phthalate detection

A photoelectrochemical molecular imprinting sensor based on Au/TiO₂ nanocomposite was constructed for the detection of dibutyl phthalate. Firstly, TiO₂ nanorods were grown on fluorine-doped tin oxide substrate by hydrothermal method. Then, gold nanoparticles were electrodeposited on TiO₂ to fabricate Au/TiO₂. Finally, molecular imprinted polymer was electropolymerized on the Au/TiO₂ surface to construct MIP/Au/TiO₂ PEC sensor for DBP. The conjugation effect of MIP accelerates the electron transfer between TiO₂ and MIP, which can greatly improve the photoelectric conversion efficiency and sensitivity of the sensor. In addition, MIP can also provide sites for highly selective recognition of dibutyl phthalate molecules. Under optimal experimental conditions, the prepared photoelectrochemical sensor was used for the quantitative determination of DBP and the results showed a wide linear range (50 to 500 nM), a low limit of detection (0.698 nM), and good selectivity. The sensor was used in a study of real water samples to show that it has promising applications in environmental analysis.