Development of photoactivated antimicrobial coatings for inanimate surfaces based on nanoparticles

MENDEZ IZARES C; SILVERO C MJ; MARTINEZ M; BECERRA MC

Lima

Congreso; 2nd International Congress on nano and Biotechnology (ICNB2); 2023

Universidad Nacional Agraria La Molina

Contamination of inanimate surfaces has always been a major concern in hospital settings because it impacts the epidemiology of nosocomial infections. One of the main focus that favors the dissemination of resistant pathogens are touch screens. The objective of this work was to develop a coating for inanimate surfaces based on bimetallic gold and silver nanoparticles that, when irradiated with LED light, activate their antimicrobial capacity. To synthesize the nanoparticles we used starch as a reducing and stabilizing agent. To characterize the nanoparticles, UV-Visible spectrophotometry and DLS were used. The maximum absorbance peaks correspond to the wavelength absorbed by gold (520 nm). In addition, another absorbance peak (420 nm) was detected in the spectrum of the bimetallic nanoparticles, corresponding to the presence of silver. The hydrodynamic sizes in water at room temperature were: 95.49 nm, 90.9%, a population with homogeneous size distribution. It is notable that in only 15 minutes of irradiation, significant inhibition of Escherichia coli is achieved, indicating an effective ability to eliminate Gram-negative microorganisms. In addition, changes in the morphology of Staphylococcus aureus colonies were observed, suggesting that the nanoparticles also have activity against Gram-positive microorganisms. Alterations in morphology were observed by transmission electron microscopy.