Sensitive detection of sulfamethoxazole by an electrochemical sensing platform with a covalent organic framework in situ grown on polyaniline

In this work, the in-situ growth of covalent organic framework materials on polyaniline (TFAB-COF@PANI) was accomplished using a facile one-pot approach. For the microanalysis of sulfamethoxazole (SMX), a highly sensitive electrochemical sensor based on the TFAB-COF@PANI complex modified glassy carbon electrode (GCE) was constructed. The X-ray powder diffraction, Fourier transform infrared spectra, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and nitrogen desorption test were used to characterize the materials. The electrochemical performance of the sensor was investigated by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance. Strong synergy was generated by the in-situ growth of TFAB-COF with a large specific surface area on PANI, which not only provides a large number of active sites but also amplifies the response signal of SMX. The resulted sensor displays a broad linear range (1–450 μM) and a low detection limit (0.107 μM) for SMX under optimal conditions. The sensor has been effectively utilized for reliable analysis of environmental water samples because of its high repeatability, reproducibility, stability, and interference resistance.