New Chitosan-Silver Nanocomposites Containing N-Nicontinyl Phosphoric Triamide as an Antibacterial- Enhancer Additive

Three new nanocomposite films of Chitosan/ Ag NPs / N-Nicontinyl phosphoric triamide, containing 3% Ag NPs and 0%, 5% and 10% phosphoric triamide were prepared and characterized by X-ray Powder Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Dispersive X-ray Spectroscopy (EDS) analysis methods. The nanocomposite films were prepared using ultrasonic waves plus cross-linking the chitosan part of biofilms as the final process and the Ag NPs were synthesized according to the citrate reduction method. XRD graph of the three nanocomposites showed all the characteristic peaks of the phosphoric triamide, 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 confirmed the desired structures. In vitro antibacterial activities of the nanocomposite were tested against two Gram-positive bacteria: Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus) and two Gram-negative bacteria: Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) in Brain-Heart Infusion (BHI) medium. Results revealed that the nanocomposite films, containing the phosphoric triamide additive, have better antibacterial effects than the one without this compound. Also, the antibacterial activity of the biofilms depends on the dosage of the phosphoric triamide and increases by raising the percentage of the additive in the structure of biofilms.