Highly sensitive detection of hazardous hydroquinone and chloramphenicol in the presence of paracetamol using cobalt tungstate (CoWO4) nanoplates modified electrode

Abstract

Recently, transition metal tungstates have been studied for their optical and electrochemical properties but synthesis to nanometer scale with controlled shape and size is still a key challenge. In the present work, cobalt tungstate nanoplates (CoW) with ∼ 25–30 nm size, have been synthesized using a simple solvothermal method. PXRD, UV-Vis, FTIR, XPS, FE-SEM, and HR-TEM have been used for the crystallographic, surface, and morphology analysis of CoW. Further, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV), techniques have been used for electrochemical studies of CoW-modified glassy carbon electrodes (CoW@GCE). CoW@GCE electrode was applied first time for the recognition of hazardous hydroquinone (HydQ) and chloramphenicol (ChPC) drugs in the occurrence of paracetamol (PaCM) through cyclic voltammetry (CV) and its selectivity and sensitivity was tested by amperometry (i-t) and differential pulse voltammetry (DPV) methods. The limit of detection (LOD) for HydQ was achieved as ∼2.21 nM with the linearity of 0.02–0.1 μM and 0.12–0.32 μM. The detection limit intended for ChPC was ∼3.05 nM with linear limits of 0.02–0.055 μM at lower concentrations and 0.055–0.11 μM at higher concentrations. Similarly, the LOD for PaCM was reported as 9.32 nM with linearity values from 0.02 to 0.1 μM and 0.1–0.21 μM. The sensitivity of the CoW@GCE electrode for HydQ, ChPC, and PaCM was found to be 57.37 μA mM-1 cm−2, 435.11 μA mM−1 cm−2, and 29.90 μA mM−1 cm−2 correspondingly.