A Novel Molecularly Imprinted Photoelectrochemical Sensor Based on g-C3N4-AuNPs for the Highly Sensitive and Selective Detection of Triclosan

A novel molecularly imprinted polymer (MIP) photoelectrochemical sensor was fabricated for the highly sensitive and selective detection of triclosan. The MIP photoelectrochemical sensor was fabricated using graphite-like carbon nitride (g-C 3 N 4 ) and gold nanoparticles (AuNPs) as photoelectric materials. The MIP/g-C 3 N 4 -AuNPs sensor used photocurrent as the detection signal and was triggered by ultraviolet light (UV-Light 365 nm). g-C 3 N 4 -AuNPs was immobilized on indium tin oxide electrodes to produce the photoelectrochemically responsive electrode of the MIP/g-C 3 N 4 -AuNPs sensor. A MIP layer of poly- o -phenylenediamine was electropolymerized on the g-C 3 N 4 -AuNPs-modified electrode to act as the recognition element of the MIP/g-C 3 N 4 -AuNPs sensor and to enable the selective adsorption of triclosan to the sensor through specific binding. Under optimal experimental conditions, the designed MIP/g-C 3 N 4 -AuNPs sensor presented high sensitivity for triclosan with a linear range of 2×10 −12 to 8×10 −10 M and a limit of detection of 6.01×10 −13 M. Moreover, the MIP/g-C 3 N 4 -AuNPs sensor showed excellent selectivity. The sensor had been successfully applied in the analysis of toothpaste samples.