May glutathione and graphene oxide enhance the electrochemical detection of caffeine on carbon paste sensor in aqueous and surfactant media for beverages analysis?

Abstract

Detecting Caffeine (CAF) is indispensable issue due to its widespread in several daily consumed beverages, food products and pharmacological preparations having various physiological effects. A novel graphene oxide-reduced glutathione modified carbon paste (GORGCP) sensor has been built on for sensitive determination of CAF in 0.01 M phosphoric acid (H3PO4) solution of pH range (1.0–5.0) in both aqueous and surfactant media (0.5 mM sodium dodecylsulfate (SDS)) was achieved. The interaction of CAF over the surface of sensor was monitored utilizing various electrochemical techniques like cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Chronoamperometry (CA), while surface characterization of electrode was performed utilizing scanning electron microscope (SEM) and energy dispersive x-ray techniques (EDX). The linear detection range of CAF was between 8 – 800 μM (r2 = 0.9676) and the limit of detection (LOD) obtained from the calibration plot was 0.153 μM. The sensor was applicable for detecting CAF in numerous real samples with recoveries of 97.76% to 101.36% without interference of any accompaning species, which ensures high selectivity and sensitivity.