Nanostructured CeO2:Ag platform for electrochemically sensitive detection of nitrophenol

Abstract 4-Nitrophenol(4-NP) is a highly toxic and hazardous substance which has a negative impact on human organs including kidney, lung, liver, blood and nervous system. Thus, its low concentration quantification with better accuracy and low testing cost is high desirable. We report on the fabrication of an electrochemical sensor for detection of 4-NP without incorporating any enzyme. The sensor comprises of highly crystalline silver doped cerium oxide (CeO2:Ag) nanoparticles (NPs; size∼ 8-10 nm) which have been synthesized by a low-cost co-precipitation method. A glassy carbon electrode (GCE) was used in this study as a 4-NP sensitive electrode wherein the electrode was modified with CeO2 with and without Ag NPs. The enhanced electro-oxidation properties due to existence of mixed Ce3+ and Ce4+ valence states, high surface area, high crystallinity, and direct electron transfer properties of CeO2:Ag NPs improved the sensing efficacy for nitrophenol (NP)detection. The sensor provided high sensitivities (4.8 µA/uM and 1.2 µA/µM) and a low limit of detection for detection of 4-NP with a wide range of concentration (7.8 µM to 1000 µM). The synthesized CeO2:Ag NPs based electrode could be potentially used for sensitive detection of other hazardous substances.