A molecularly imprinted electrochemical sensor based on cationic intercalated two-dimensional titanium carbide nanosheets for sensitive and selective detection of triclosan in food samples

An advanced molecularly imprinted electrochemical sensor (MIECS) based on two-dimensional materials MXene was developed for determination of triclosan (TCS) in food samples for the first time. Two-dimensional titanium carbide (Ti3C2Tx) were introduced to improve electrochemical response of the MIECS. K+ ions were spontaneously inserted into Ti3C2Tx nanosheets to form K+-Ti3C2Tx by soaking in alkali solution, thus improving the sensitivity of the sensor. Molecularly imprinted polymers (MIP) were prepared by electropolymerization of para aminobenzoic acid (p-ABA), which can specifically recognize TCS. Under optimal conditions, the linear relationship between the current intensity and TCS concentration was obtained from 10 nmol L−1 to 50 μmol L−1 with a low detection limit of 1.18 nmol L−1. The proposed MIECS showed good repeatability for detecting TCS at a concentration of 500 nmol L−1 solution by preparing five parallel modified electrodes, with a relative standard deviation (RSD) of 3.42%. At the spiked concentration levels of 0.05, 0.1, 0.5 mg L−1/mg kg−1, the recoveries range of TCS in peach juice, onions and fish samples were 86.38%–95.52%. The proposed MIECS combining the advantages of Ti3C2Tx and MIP exhibited good sensitivity and selectivity, providing strategy of utilizing MXenes in the construction of electrochemical sensing platform and holding great promise in the field of food safety.