A Molecularly Imprinted Electrochemical Sensor Based on TiO@TiCT for Highly Sensitive and Selective Detection of Chlortetracycline.

In view of the serious side effects of chlortetracycline (CTC) on the human body, it is particularly important to develop rapid, sensitive, and selective technologies for the detection of CTC in food. In this work, a molecularly imprinted electrochemical sensor with [Fe(CN)] as signal probe was proposed for the highly sensitive and selective detection of CTC. For this purpose, TiO, which acts as an interlayer scaffold, was uniformly grown on the surface of TiCT sheets through a simple two-step calcination process using TiCT as the precursor to effectively avoid the stacking of TiCT layers due to hydrogen bonding and van der Waals forces. This endowed TiO@TiCT with large specific surface, abundant functional sites, and rapid mass transfer. Then, polypyrrole molecularly imprinted polymers (MIPs) with outstanding electrical conductivity were modified on the surface of TiO@TiCT via simple electro-polymerization, where the pyrrole was employed as a polymeric monomer and the CTC provided a source of template molecules. This will not only provide specific recognition sites for CTC, but also facilitate electron transport on the electrode surface. The synergistic effects between TiO@TiCT and polypyrrole MIPs afforded the TiO@TiCT/MIP-based electrochemical sensor excellent detection properties toward CTC, including ultra-low limits of detection (LOD) (0.027 nM), a wide linear range (0.06-1000 nM), and outstanding stability, reproducibility, selectivity, and feasibility in real samples. The results indicate that this strategy is feasible and will broaden the horizon for highly sensitive and selective detection of CTC.