Antimicrobial, Photocatalytic, and Non‐Enzymatic Glucose Sensors Applications of Nanoplate‐Structured CuO:rGO Nanocomposites**

Abstract In the current work, reduced graphene oxide (rGO) layers (20, 40, 60, and 80 mg) are decorated over the surface of copper oxide (CuO) nanoparticles using a simple and in‐situ hydrothermal reduction method. The notable variation in the XRD peak intensity of CuO:rGO samples indicates the formation of nanocomposite. HRTEM and FESEM analysis reveal a nanoplate‐like morphology with uniform particle distribution. Further, the nanocomposites are characterized using FTIR, DRS UV Visible, and XPS techniques. Here, multi‐functional applications of the synthesized nanocomposites are investigated through photocatalytic dye degradation, antimicrobial, and electrochemical sensing analyses. The photocatalytic activity of synthesized CuO:rGO nanocomposites with hydrogen peroxide (H 2 O 2 ) showed higher efficiency (98 %) than pure CuO. The effects of pH, various scavengers, and different dyes on the degradation efficiencies of CuO:rGO nanocomposites are also investigated. Using the agar well diffusion method, these nanocomposites exhibited a zone of inhibition value of 32 mm against both gram positive (Bacillus subtilis) and gram negative (Escherichia coli) bacterial strains when compared to pure rGO and CuO nanoparticles. Also, nanocomposites are found to be suitable for non‐enzymatic glucose sensing with a detection limit in the range from 0.05 to 4 mM, as evidenced from the cyclic voltammetry (CV) analysis.