New Chitosan/Ag/Carbacylamidophosphate nanocomposites: Preparation and antibacterial study

Two new Chitosan-based nanocomposite films were prepared: Chitosan /7% Ag nanoparticles (NPs) (NC1) and Chitosan/7% Ag NPs/5%Carbacylamidophosphate(NC2), in which the carbacylamidophosphate derivitive is N-Nicotinyl-N′,N″- bis(hexamethylenyl) phosphorictriamide (NHE) with the formula: C5H4NC(O)NHP(O)(NC6H12)2. X-ray Powder Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDS) methods were used to characterize and confirm the prepared frameworkrs. XRD graph of the two nanocomposites showed all the characteristic peaks of NHE, Ag NPs, and chitosan, indicating the fact that the preparing process has not made any changes in the phases of the nanocomposites components. All the SEM micrographs and EDS analysis results also confirmed the desired structures. To study the effect of the additive NHE on the antibacterial activity of the films, in vitro antibacterial tests were done on the prepared nanocomposites against two Gram-positive (Staphylococcus aureus, Bacillus cereus) and two Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa) in Brain-Heart Infusion(BHI) medium. Results showed that the antibacterial effects of the nanocomposite containing NHE on each of the four bacteria is stronger than those for the nanocomposite without NHE.