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

- Facile synthesis of spherical graphene and CuO:GNS nanocomposite.
- Sensitive detection of cholesterol with LOD 78 μM.
- Sensitive detection of H2O2 with LOD 6.8 μM.
- Molecular logic gate: AND logic gate implementation of the sensor.
- Improved biocompatibility of CuO:GNS nanocomposite.

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 0.1 mM -0.8 mM with LOD as low as 78 μM. This nanocomposite sensor also detected a very low concentration of H2O2 (0.01-0.1 mM) with LOD of 6.88 μM. 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.

A CuO:Graphene Nanosphere (CuO:GNS) based sensor was designed and synthesized which can provide visual detection of Cholesterol and H2O2. A molecular logic gate is proposed implementing “AND” logic system based on CuO:GNS and Cholesterol input. The CuO:GNS was found to have better cytocompatibility than standalone CuO.101