Cytocompatible peroxidase mimic CuO:graphene nanosphere composite as colorimetric dual sensor for hydrogen peroxide and cholesterol with its logic gate implementation

Abstract

Faster and easy detection of cholesterol still remains a challenge. Thus, by introducing colorimetric sensor for detection of cholesterol may lead to the fabrication of a ready to use sensing strip. Our present work demonstrates the use of a cytocompatible CuO:Graphene nanosphere (CuO:GNS) composite as a peroxidase mimic for detection of H2O2 and free cholesterol. The synthesized CuO:GNS composite was investigated systematically for structural, morphological and functional aspects. The proposed methodology involves detection of H2O2 produced during oxidation of free cholesterol in the presence of cholesterol oxidase. The nanocomposite sensor has shown excellent detection sensitivity for cholesterol and has demonstrated a linear response in the range of 0.1mM –0.8mM with LOD as low as 78μM. This nanocomposite sensor also detected a very low concentration of H2O2 (0.01–0.1mM) with LOD of 6.88μM. An AND logic gate system based on CuO:GNS and Cholesterol input was also proposed. The CuO:GNS was found to have better cytocompatibility than standalone CuO.