Development and Evaluation of Aztreonam-Functionalized Graphene Oxide Nanosheets for Enhanced Antibacterial Efficacy Against Multidrug-Resistant Bacteria

Abstract

     The present study aimed to develop a new nanocomposite by covalently functionalizing graphene oxide (GO) nanosheets with Aztreonam (AT), to target multidrug-resistant bacteria isolated from wound infections. The successful synthesis of the GO-AT nanocomposite was confirmed using advanced characterization techniques. Ultraviolet-Visible (UV-Vis) spectroscopy peaks were observed at 226.5nm and 217.1nm for GO and GO-AT, respectively. Fourier Transform Infrared (FTIR) spectroscopy exposed functional groups. Transmission Electron Microscopy (TEM) revealed morphological features, including GO sheets not exceeding 6nm and 12nm for GO-AT. Zeta potential indicated high colloidal stability (-33.7mV). The Raman spectroscopy characterization demonstrated an increased I_D/I_G ratio (0.90 to 1.14), indicating higher defect levels due to functionalization. Cytotoxicity assays conducted on selected cell lines showed an IC₅₀ value of 1761.3363µg/ml, confirming a wide safety margin for potential biomedical applications. The antibacterial efficacy of the GO-AT was evaluated through minimum inhibitory concentration (MIC) testing, demonstrating synergistic antibacterial activity against resistant strains, as confirmed by statistical analysis (p<0.01). The results highlight a significant synergistic antibacterial effect of Aztreonam-modified graphene oxide nanosheets against MDR isolates for both Gram-positive and Gram-negative bacteria.