Optical properties and antimicrobial effects of silver nanoparticles synthesized by femtosecond laser photoreduction

Autor(es)

Courrol, Daniella dos Santos ^[1] ; Borges Lopes, Carla Regina ^[2] ; Cordeiro, Thiago da Silva ^[3] ; Franzolin, Marcia Regina ^[1] ; Vieira Junior, Nilson Dias ^[3] ; Sarnad, Ricardo Elgul ^[3] ; Courrol, Lilia Coronato ^[2]

Afiliação do(s) autor(es)

^[1] Inst Butantan, Lab Bacteriol, Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Fis, Lab Lasers & Opt Biomed Aplicada, Diadema, SP - Brazil

^[3] IPEN CNEN SP, Ctr Lasers & Aplicacoes, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: OPTICS AND LASER TECHNOLOGY; v. 103, p. 233-238, JUL 2018.
• Citações Web of Science: 7

Resumo

Silver nanoparticles exhibit a powerful antimicrobial action showing a pronounced potential to be widely used against drug resistance bacteria. The present work describes the optical properties and antimicrobial effect of silver nanoparticles produced by femtosecond laser photoreduction of AgNO3 in the presence of tryptophan water solution. The advantages of this method are the absence of hazardous chemical reducing agents in the solution, and the versatile dimensional control achieved. The synthesized silver nanoparticles were characterized by absorption and fluorescence spectroscopy and their antibacterial activity were determined by monitoring the cell viability of Escherichia coli. The effects of the silver nanoparticles concentration and laser parameters (exposure time and pulse energy), on the formation of the nanoparticles, and its influence on the bacteria growth inhibition were studied. The prepared silver nanoparticles exhibited suitable antimicrobial properties. The results demonstrated that the nanoparticles concentration plays an important role in their bactericidal efficacy. The increase in the laser energy caused an increase in E. coli growth inhibition. Irradiations with energies around 300 mu j for 60 min presented high antimicrobial activity due to the presence of kynurenine, sub product of tryptophan photolysis. The first-time formation mechanism of tryptophan silver nanoparticles in high optical intensities was also discussed. (C) 2018 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 14/06960-9 - Utilização de nanopartículas de ouro como agente teranóstico de aterosclerose
• Beneficiário: Lilia Coronato Courrol
• Modalidade de apoio: Auxílio à Pesquisa - Regular