Synergistic effect of graphene oxide and silica nanocomposites towards multifunctional biomedical applications

Abstract

The development of advanced nanomaterials (NMs) has recently gained significant attention because of their potential in addressing various biomedical and healthcare challenges. This study focuses on the synthesis of silica (SiO2) nanoparticles (NPs) and their nanocomposite with graphene oxide (GO-SiO2), using a multifunctional approach to enhance antibacterial, antibiofilm, antioxidant, and antidiabetic properties. The synthesis of the GO-SiO2 involves the controlled growth of SiO2 NPs on the surface of the graphene oxide (GO) sheets. The synthesized NPs were characterized by UV–Visible spectroscopy, Fourier-Transform Infrared (FTIR) Spectroscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray (EDX) Spectroscopy. The crystallite sizes of SiO2 and GO-SiO2 were found to be 23.07 nm and 32.07 nm, respectively, by XRD analysis and 27.03 nm and 43.11 nm, respectively, by SEM. The Band gap of SiO2 was decreased from 3.76eV to 3.45eV in GO-SiO2. Disc diffusion method was used to perform antibacterial activity whereas ampicillin and moxifloxacin were taken as reference drugs. Biofilm inhibitions and minimum inhibitory concentrations were measured by microtiter plate method. The composite has shown higher antimicrobial activities against S. aureus, S. aureus MDR, K. pneumoniae, P. aeruginosa, P. aeruginosa MDR, E. coli, and P. vulgaris as compared to SiO2 NPs and GO. When IC50 values were compared with those of control (acarbose), GO-SiO2 and SiO2 demonstrated the highest and lowest antidiabetic activities, respectively. A 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging process was used to evaluate the antioxidant potential of NMs using ascorbic acid as a reference. GO-SiO2 displayed the negligible IC50 value compared to both SiO2 and GO. The nanocomposite (GO-SiO2) has shown higher antibacterial, antibiofilm, antioxidant, and antidiabetic potential as compared to those of GO and SiO2NPs.