Electrochemical sensor based on molecularly imprinted polypyrrole-MWCNTs-OH/covalent organic framework for the detection of ofloxacin in water

A platform was developed to accurately detect the content of ofloxacin (OFX) based on molecularly imprinted polypyrrole-MWCNTs-OH/1,3,5-Tris(4-aminophenyl) benzene (TAPB)-2,5-dimethoxybenzene-1,4-dicarboxaldehyde (DMTP)-covalent organic framework (MIP-MWCNTs-OH/COF)–modified glassy carbon electrode (GCE) sensor (MIP-MWCNTs-OH/COF/GCE). The complex of MWCNTs-OH and COF synergistically enhanced the active area and electrochemical signal, based on which a molecularly imprinted membrane was polymerized on its surface to further improve the selectivity. Under optimized conditions, the prepared MIP-MWCNTs-OH/COF/GCE sensor exhibited strong detection performance to OFX in a linear range 1.969 × 10⁻¹¹–9.619 × 10⁻⁹ M with the limit of detection (LOD, 3S/N) of 4.989 × 10⁻¹² M, excellent selectivity, stability, and reproducibility. Furthermore, the MIP-MWCNTs-OH/COF/GCE sensor can be successfully applied to the detection of OFX in lake water and eye drops with a relative standard deviation (RSD) of less than 4.95%, indicating its high potential in practical applications.