In-situ incorporation of highly dispersed silver nanoparticles in nanoporous carbon nitride for the enhancement of antibacterial activities

Graphitic carbon nitride with suitably incorporated functionality has attracted much interest in the areas of environmental treatments, clean energy, sensing, and photocatalyst. However, the role of graphitic nanoporous carbon nitride (NCN) matrix from single carbon-nitrogen (C-N) source, aminoguanidine HCl as a precursor and close intimate contact between silver nanoparticles (Ag NPs) dispersed in NCN and bacteria has rarely been demonstrated. Herein, we demonstrate a nanostructure of Ag NPs-incorporated NCN sample ([email protected]) as an antibacterial agent against both wild type and the multidrug-resistant Escherichia coli (E. coli) pathogens. In-situ ultrasonication method was used to ensure the homogeneous mixing of the Ag NPs and a single C-N precursor at the molecular level so that pore size (PS) (9.17 nm) of SBA15 silica could be impregnated with ultrasonicated Ag NPs and a single C-N precursor. The porous structure, compositions, and structural information of the final nanocomposites were confirmed by using various analytical techniques such as XRD, TEM, BET surface area (SA) measurements, XPS, and UV. Then, the antibacterial activities of the NCN and [email protected] against both wild type and the multidrug-resistant Escherichia coli (E. coli) pathogens were also carried out and results from the in-vitro studies have shown the excellent bactericidal effect of the highly dispersed Ag NPs containing [email protected] sample against both E. coli strains. Results have confirmed that the antibacterial activity of the [email protected] sample is found to be higher than pure NCN, indicating that in-situ incorporated Ag NPs in NCN matrix have played significant role for enhancing antibacterial activities. Surprisingly, in the presence of [email protected], the reduction in minimum inhibitory concentration (MIC) was higher (64-fold reduction) compared to its susceptible wild type (32-fold reduction) E. coli. These results indicate the potential application of [email protected] for inactivating infectious bacterial pathogens implicated in multidrug resistance.