Novel electrochemical sensor based on molecularly imprinted polymer combined with L-His-MWCNTs@PDMS-5 nanocomposite for selective and sensitive assay of tetracycline

Herein, we designed a novel electrochemical sensor by modifying L-histidine functionalized multi-walled carbon nanotubes (L-His-MWCNT)-molecularly imprinted polymer for the selective, rapid, and simple detection of tetracycline (TET). Firstly, PDMS-1000 was decorated with pristine multi-walled carbon nanotubes (P-MWCNTs) by physical adsorption and then functionalized with L-histidine (L-His-MWCNTs@PDMS-5). The MIP-based electrochemical sensor was constructed on a glassy carbon electrode (GCE) via sol-gel consisting of tetraethoxysilane (TEOS) and cetyltrimethylammonium bromide (CTAB) with L-His-MWCNTs@PDMS-5 in the presence of TET. The structural characterization of P-MWCNTs and polymer nanocomposite were examined by Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size distribution techniques. The performance of the newly developed sensor was evaluated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) methods. The limit of detection (LOD) was found to be 2.642 x 10-12 M, while a linear operating range of 1 x 10-11 M-1 x 10-10 M was found. The validity of the developed sensor was checked by TET detection in capsule dosage form, human serum, and tap water samples, and the recovery results were found to be 99.69%, 98.92%, and 100.60%, respectively. The developed L-His-MWCNTs@PDMS-5/MIP sensor demonstrated an excellent electrochemical response for TET.