Development of an amplified nanostructured electrochemical sensor for the detection of cefixime in pharmaceuticals and biological samples

As one of the third generation of cephalosporin category, cefixime has a considerable activity towards both gram-positive and gram-negative bacteria so the quantitative analysis is considerable. Based on the synthesized reduced graphene oxide/CoFe2O4/ionic liquid (IL) (1-Ethyl-3-Methylimidazolium) (IL/CoFe2O4/rGO) nanocomposite, a modified carbon paste electrode (CPE) was selected as a sensor for determining cefixime. The structure and ability of nanostructures are investigated by various techniques containing scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), differential pulse voltammetry (DPV), cyclic voltammetry (CV) and chronoamperometry (CHA). The suggested sensor was successfully used for the simultaneous determination of cefixime, mefenamic acid, and acetaminophen. Under optimized settings, the oxidation peak current was obtained in the two linear ranges from 0.06 to 10 mu M (0.02-4.53 mu g.ml(-1)) (R-2 = 0.9909) and 10.0-700.0 mu M (4.53-317.394 mu g.ml(-1)) (R-2 = 0.9970) along with the detection limit of cefixime 0.035 mu M (0.015 mu g.ml(-1)). The values of electro-transfer coefficient (alpha) and diffusion coefficient (D) were achieved 0.9 and 1.17 x 10(-6) cm(2)s(-1). The electro-oxidation of cefixime occurs at an approximate potential of 0.85 V with an irreversible oxidation peak. The F-test (precision) and t-test (accuracy) were used for comparing the obtained results in urine samples. The proposed modified electrode shows high performance for the analysis of cefixime, mefenamic acid, and acetaminophen in pharmaceuticals and biological samples with good results.