Myco-architecture of proficient antibacterial CuO/Ag2O-grafted graphene oxide nanoconjugates: Characterization and Congo red degradation-assisted by the activation of peroxymonosulfate

The engineering of nanobiomaterials aligns with the Sustainable Development Goals and green chemistry principles. Fungi act as highly efficient nano-biofactories due to their ability to produce a wide range of bioactive metabolites and enzymes that facilitate the green synthesis of nanoparticles (NPs) with unique optical, structural, and functional properties. Herein, a Trichoderma virens filtrate was utilized for the bioengineering of a nanoconjugate (NC). A copper oxide/silver oxide-grafted graphene oxide NC (CuO/Ag₂O@GO) was synthesized by grafting GO with the fungal-engineered CuO and Ag₂O NPs in a one-pot reaction using 20 mM of CuSO₄·5H₂O and AgNO₃. The optical, structural, and morphological characteristics of the CuO/Ag₂O@GO NC were thoroughly analyzed. X-ray diffraction showed the formation of diamond carbon with a cubic crystal system, with monoclinic tenorite CuO and cubic Ag₂O. The average crystallite size of the NC was 21.02 nm. The presence of Cu K, Ag L, O K, and C K was confirmed by energy-dispersive X-ray analysis. The average hydrodynamic size of the synthesized NC was 204.4 nm. The zeta potential analysis of the CuO/Ag₂O@GO NC was measured to be +10.1 mV, confirming its good stability. The respective D and G bands of the CuO/Ag₂O@GO NC occurred at wave numbers of 1369 and 1580 cm⁻¹. X-ray photoelectron spectroscopy validated the electron-binding affinity of CuO, Ag₂O, and GO. A Tauc plot was studied using data from a UV–Vis-DRS spectrophotometer, from which the optical band gap was estimated as 2.57 eV. The surface plasmon resonance λ_max characteristic peaks of GO were observed at 236 and 300 nm, with an absorption band at 450 nm characteristic of the CuO and Ag₂O NPs. The CuO/Ag₂O@GO NC demonstrated excellent inhibitory activity against a broad spectrum of pathogenic bacteria using Kirby−Bauer disk diffusion antibacterial testing. For environmental applications, the CuO/Ag₂O@GO NC displayed efficient peroxymonosulfate-assisted degradation of Congo red with removal efficiencies averaging around 70 % for the initial concentration range of 20–50 ppm. The findings revealed the potency and remarkable performance of the CuO/Ag₂O@GO NC for environmental applications. Several avenues for future research can further enhance the utility of this composite and address existing challenges by optimizing its synthesis, understanding its mechanisms of action, and exploring its potential in diverse fields.