Facile Grafting of Silver Nanoparticles into Copper and Guanosine 5′-Monophosphate Metal Organic Frameworks (AgNPs@Cu/GMP): Characterization and Antimicrobial Activity

Silver nanoparticles (AgNPs) are effective antibacterial agent but lack of stability and rapid aggregation limits their antibacterial efficiency in biomedical applications. To overcome these shortcomings, various strategies have been adopted so far but those strategies are not much effective at room temperature and in absence of external stimuli. Thus, herein, we have successfully grafted AgNPs into copper and guanosine 5′-monophosphate (Cu/GMP) metal organic frameworks at room temperature without using any external stimuli. The loading encapsulation ratio of AgNPs into Cu/GMP was approx. 99.83% at neutral pH. The AgNPs@Cu/GMP was characterized by various techniques, such as energy-dispersive x-ray spectroscopy, transmission electron microscopy, x-ray diffraction and Fourier transforms infrared spectroscopy. All these techniques have confirmed the loading of AgNPs into Cu/GMP (MOFs). Furthermore, antimicrobial activities of AgNPs, Cu/GMP and AgNPs@Cu/GMP were assessed against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacterium. As compared to pure AgNPs, the composite material AgNPs@Cu/GMP had shown significant growth of inhibition zones against tested bacteria. The stability of AgNPs@Cu/GMP was remarkable, i.e., six times higher than free AgNPs even after 15 days. These results make AgNPs encapsulated into Cu/GMP a promising antimicrobial candidate and is expected to deliver an advance platform to pharmaceuticals and biomedical applications. Graphic abstract