Nanoparticles are being increasingly used in day-to-day life. Therefore, concerns have been raised regarding their interactions with the surrounding environment. This study focused on a simple green method for synthesizing silver nanoparticles (Ag-NPs) in an autoclave at 15 psi (103 kPa) and 121°C. An aqueous solution of AgNO as a precursor of Ag-NPs and gelatin (type B) reducing and/or stabilizing (capping) agent were used. The effect of various AgNO concentrations of certain gelatin concentration and various gelatin concentrations at constant AgNO concentration, and autoclaving time, was studied. UV-Vis spectra ascribed that the presence of localized surface plasmon resonance (SPR) of the synthesized Ag-NPs. TEM images and the selected area of electron diffraction confirmed, the formation of Ag-NPs with a diameter of approximately 5 ±0.35 nm. Furthermore, FT-IR revealed that a gelatin polymer matrix stabilized the synthesized Ag-NPs. The Well diffusion assay was used to test the effect of Ag-NPs on six clinical bacterial isolates, where Gram positive bacteria were more susceptible to Ag-NPs than Gram negative bacteria. Therefore, Ag-NPs capped by gelatin have remarkable potential effect as an antibacterial agent, and they not only have various medical applications but can also be used in biological, pharmaceutical and industrial fields.

The current time increase in the prevalence of antibiotic resistant 'super-bugs' and the risks associated with food safety have become global issues. Therefore, further research is warranted to identify new and effective antimicrobial substances. Silver nanoparticles (Ag-NPs) were synthesized by autoclaving technique using, different concentrations of Ag salt (AgNO) solution (1, 5, 10, and 25 mM). Their presence was confirmed by a surface plasmon resonance band at ∼435 nm using UV-Vis absorption spectra. The morphology of the synthesized Ag-NPs stabilized by polyacrylamide (PAM) was examined by TEM, SAED, and EDS. TEM images revealed that the synthesized Ag-NPs had an average diameter of 2.98±0.08 nm and SAED and EDS results confirmed the formation of Ag-NPs. In addition, FT-IR spectroscopy revealed that a PAM polymer matrix stabilized the Ag-NPs. The well diffusion method, was used to test, Gram positive and Gram negative bacteria were examined. Also the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were studied against Ag-NPs. The Ag-NPs exhibited strong inhibitory activity, MIC and MBC against the tested clinical bacterial isolates. These results suggest that Ag-NPs stabilized in PAM are highly effective against clinical bacterial isolates can be applied in medical fields.

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Silver nanoparticles (AgNPs) were synthesised with hydrothermal autoclaving technique by using AgNO salt (silver precursor) at different concentrations (0.01, 0.1, 0.55, 1.1, 5.5, and 11 mM) and porcine skin (1% (w/v) ) gelatin polymeric matrix (reducing and stabiliser agent). The reaction was performed in an autoclave at 103 kPa and 121°C and the hydrothermal autoclaving exposure time and AgNO molar concentration were varied at a constant porcine skin gelatin concentration. The as-prepared AgNPs were characterised by UV-visible spectroscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. The antibacterial properties of AgNPs were tested against gram-positive and gram-negative bacteria. Furthermore, 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide and 2,2-diphenyl-1-picrylhydrazyl assays were used to test whether the synthesised AgNPs can be potentially applied in cancer therapy or used as an antioxidant. This approach is a promising simple route for synthesising AgNPs with a smaller average particle 10 nm diameter. Furthermore, AgNPs exhibited a good cytotoxicity activity, reducing the viability of the liver cancer cell line HepG2 with a moderate IC; they also showed a low-to-fair antioxidant activity. In addition, AgNPs had a remarkable preferential antibacterial activity against gram-positive bacteria than gram-negative bacteria. Therefore, these fabricated AgNPs can be used as an antibacterial agent in curative and preventive health care.