A vanillin electrochemical sensor based on molecularly imprinted poly(1-vinyl-3-octylimidazole hexafluoride phosphorus) −multi-walled carbon nanotubes@polydopamine-carboxyl single-walled carbon nanotubes composite

A highly selective electrochemical sensor was constructed for the detection of vanillin (VA). It was fabricated by molecular imprinting on the surface of polydopamine-functionalized multi-walled carbon nanotubes (MWNTs-PDA), followed by coating on a carboxyl single-walled carbon nanotubes modified electrode. The molecularly imprinted polymer was synthesized with 1-vinyl-3-octylimidazole hexafluoride phosphorus ([VOIm]PF6) as monomer, VA as template and ethylene glycol dimethacrylate as cross-linker. The carboxyl single-walled carbon nanotube was introduced for improving conductivity and sensitivity. The sensor could recognize VA from its analogs and possible coexistent substances. The response peak current and VA concentration showed good linear relationship in the range of 0.2 μM-10 μM, with a sensitivity of 1.22 μA/μM mm2. The detection limit was 0.1 μM (S/N = 3). It was applied to the determination of VA in real samples with satisfactory results.