Host Guest Inclusion Complex Modified Electrode for the Sensitive Determination of a Muscle Relaxant Drug

Abstract

Electrochemical sensor based on cyclodextrin (CD)/ionic liquid crystal (ILC)/graphene (RGO) modified glassy carbon (GC) (GC/ILC/RGO/ILC/CD) electrode was constructed for the determination of methocarbamol (MC). The enhanced electrochemical performance of the sensor is due to the synergistic effect triggered by its individual components: surface area of RGO, ionic conductivity of ILC and the concentrating effect of CD through formation of stable host-guest “CD/MC” inclusion complex which affected the electron transfer rate. In this composite the moderate viscosity of ILC that penetrates between the graphene sheets results in filling any existing voids and act as ion carriers between the graphene sheets resulting in more conductive composite and homogenous surface for further assembling of the CD in ordered form. Under optimized conditions, the LDR was 4 × 10−8–1 × 10−6 mol L−1 for MC determination (R = 0.999) and LOD 6.64 × 10−12 mol L−1. The sensor was highly sensitive and successfully applied for direct determination of MC in human urine and in pharmaceutical formulation samples with good recovery results. This procedure was also successfully applied for simultaneous determination of MC, uric acid (UA), ascorbic acid (AA) and MC, dopamine (DA) or MC, acetaminophen (APAP) in their mixtures. The GC/ILC/RGO/ILC/CD showed also high reproducibility, selectivity and anti-interference ability.