Fabrication of nanostructured molecularly imprinted polymer as enantioselective sensor and sorbent for L-phenylalanine benzyl ester

A novel and unique chiral adsorbent and sensor for an ester of aminoacid, L-phenylalanine benzyl ester (L-PABE), has been synthesised on vinyl group incorporated multiwalled carbon nanotube (MWCNT) using a molecular imprinting approach. In this, molecular imprinted polymers (MIPs) were fabricated by L-PABE as a target molecule supported o MWCNT using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent using a simple thermal bulk polymerisation method. Fourier transform infrared spectroscopy (FT-IR), 1H-NMR titration study and UV–Vis. spectroscopic analysis was carried out to investigate the interaction of template-functional monomer complexes formed in the solution earlier to polymerisation. FT-IR, scanning electron microscopy (SEM), X-ray diffraction technique (XRD), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) were used to determine the structure and morphology of the fabricated polymer-nano composites. The corresponding enantioselective sensor is fabricated on the platinum electrode with imprinted and non-imprinted polymer composites, and their electrochemical parameters were examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The fabricated MWCNT-MIP established favourable specificity, better sensitivity, maximum stability and a good adsorption capacity for L-PABE molecule compared with the conventional polymer.