A novel electrochemical sensor based on molecularly imprinted polymer nanocomposite platform for sensitive and ultra-selective determination of citalopram

Abstract

• A novel sensing platform based on MIP/hNiNS/AMWCNT@GONRs composite was designed as the modifier for GCE. • For the first time the modified glassy carbon electrode (MIP/hNiNS/AMWCNT@ GONRs/GCE) was used to determine citalopram (CIT). • The sensor showed excellent selectivity and sensitivity towards determination of CIT. • The proposed sensor was applied successfully for determination of CIT in real samples. Citalopram (CIT) is an antidepressant of the selective serotonin reuptake inhibitor class widely used worldwide, so the development of analytical methods to determine it in real samples is essential for treatment purposes and drug development. This work presented an electrochemical-specific sensor for CIT based on the molecular imprinting technique. The sensor was fabricated by electropolymerizing molecularly imprinted polymer (MIP) film onto hollow nickel nanospheres (hNiNS)/activated multiwalled carbon nanotubes@graphene oxide nanoribbons (AMWCNTs@GONRs) composite modified glassy carbon electrode (GCE). The excellent synergistic effect of the combination of hNiNS and AMWCNTs@GONRs composite shows significantly enhanced electrocatalytic activity for CIT, which lead to high sensitivity of the sensor. The electropolymerized MIP provides specific imprinted sites, which can increase the selectivity for CIT. The preparation of the MIP/hNiNS/AMWCNT@GONRs/GCE was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and electrochemical methods, including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical properties of the sensor were studied using differential pulse voltammetry (DPV) and CV. Main effective parameters on the performance of the imprinted electrodes such as electropolymerization cycles, pH buffer solution, incubation time and concentrations of template molecules were checked and optimized. The fabricated sensor displayed two linear dynamic ranges from 0.5 to 10 µM and 10 to 190 µM with a limit of detection (LOD, S/N = 3) of 0.042 µM. Examining the interfering effect of some structurally related compounds and some potential interferences existing in biological fluids on the analysis of citalopram showed that the designed MIP sensor could identify CIT selectively. Moreover, the constructed electrode exhibited good repeatability, reproducibility, stability and rapid response time for the electrochemical analysis of CIT. The presented sensor was successfully utilized for determining the CIT in real samples.