Rapid Detection and Visible Light driven Photocatalytic Degradation of Chloramphenicol in Aqueous Medium using CoAl2O4/rGO Nanocomposite

Abstract

Nanoscale materials employed in electrochemical detection of chloramphenicol (CAP) have attracted significant research attention due to concerns regarding antibiotic residue detection in water and food products, associated with widespread contamination of water reservoirs by human and veterinary waste. Graphene-based materials are especially intriguing because of their π-π interactions. In the present work, CoAl2O4 and reduced graphene oxide (rGO) have been used for modification of glassy carbon electrode (GCE). The synthesized CoAl2O4/rGO nanocomposite was characterized through various techniques such as XPS, FE-SEM, EDS, Raman spectroscopy, FTIR, and HR-TEM. The electrochemical performance of CoAl2O4/rGO for CAP determination was evaluated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry and chronoamperometry techniques. The CoAl2O4/rGO exhibited linear detection limit = 13.5 nM, limit of quantification = 19.34 nM and sensitivity = 1.1505 μA μM–1 cm–2 with linear calibration equation of Ipc (μA) = 0.3895 [CAP]/ (μM) + 0.1599 having R2 = 0.9957. Additionally, CoAl2O4/rGO showed excellent selectivity and anti-interference capabilities towards CAP recognition. The CoAl2O4/rGO showed promising potential for CAP analysis in tap water, river water and pharmaceutical wastewater with good % recovery rates. Moreover, the CoAl2O4/rGO nanocomposite is an efficient catalyst for the photodegradation of CAP as revealed by the UV–vis spectroscopy results which showed that CoAl2O4/rGO nanocomposite exhibit 100% CAP degradation efficiency within 80 min under natural sunlight and displays good stability and reusability of catalyst.