Síntesis de nanopartículas de plata a partir de placas radiográficas y su aplicación como bactericida

Abstract

The radiographic plates after a medical diagnosis were discarded without prior treatment, these radiographic wastes contain silver halide crystals in their structure that reaches effluents and soils generating contamination. The objective of the research work was to synthesize silver nanoparticles from radiographic plates and evaluate their application as a bactericidal agent for the reduction of colony-forming units (CFUs) of Pseudomonas aeruginosa. Silver recovery was performed by immersing radiographic plates in an oxalic acid solution; the recovered silver was treated with nitric acid forming the silver nitrate salt that serves as a precursor for nanoparticle synthesis; silver ions were reduced to nanoparticles using sodium borohydride and the impregnated silver nanoparticles in Agave americana fiber. The nanoparticles and nanocomposite were characterized using techniques such as UV-Vis’s spectroscopy, IR spectroscopy, scanning electron microscopy (SEM) and dispersed energy X-ray spectroscopy (EDS or EDX), where nanoparticles impregnated with the agave fiber in a spherical shape with a diameter between 50 and 100 nm were obtained. The bactericidal activity of the nanocomposite in Pseudomonas aeruginosa was evaluated, in dose 1 (5%) it eliminated 99.62% of the CFU/mL in the 6 hours of contact, while dose 3 (1%) reduced the CFU/mL by 82.96%, the analysis of variance showed that the contact time that the nanocomposite has with the bacterial solution significantly influences the reduction of CFU/mL. Silver nanoparticles synthesized from radiographic plates show promising bactericidal activity in Pseudomonas aeruginosa.