Anti-adhesion and antibacterial activity of silver nanoparticles supported on graphene oxide sheets.
This work reports on the preparation, characterization and antibacterial activity of a nanocomposite formed from graphene oxide (GO) sheets decorated with silver nanoparticles (GO-Ag). The GO-Ag nanocomposite was prepared in the presence of AgNO3 and sodium citrate. The physicochemical characterization was performed by UV-vis spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy and transmission electron microscopy (TEM). The average size of the silver nanoparticles anchored on the GO surface was 7.5 nm. Oxidation debris fragments (a byproduct adsorbed on the GO surface) were found to be crucial for the nucleation and growth of the silver nanoparticles. The antibacterial activity of the GO and GO-Ag nanocomposite against the microorganism Pseudomonas aeruginosa was investigated using the standard counting plate methodology. The GO dispersion showed no antibacterial activity against P. aeruginosa over the concentration range investigated. On the other hand, the GO-Ag nanocomposite displayed high biocidal activity with a minimum inhibitory concentration ranging from 2.5 to 5.0 μg/mL. The anti-biofilm activity toward P. aeruginosa adhered on stainless steel surfaces was also investigated. The results showed a 100% inhibition rate of the adhered cells after exposure to the GO-Ag nanocomposite for one hour. To the best of our knowledge, this work provides the first direct evidence that GO-Ag nanocomposites can inhibit the growth of microbial adhered cells, thus preventing the process of biofilm formation. These promising results support the idea that GO-Ag nanocomposites may be applied as antibacterial coatings material to prevent the development of biofilms in food packaging and medical devices.
Laboratório de Química do Estado Sólido, Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, Campinas 13083-970, São Paulo, Brazil. Electronic address: an.ffaria@gmail.com.
Andreia Fonseca
AF
de Faria
Laboratório de Química do Estado Sólido, Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, Campinas 13083-970, São Paulo, Brazil.
Diego Stéfani Teodoro
DS
Martinez
Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul, Caixa Postal 15.090, Porto Alegre 91501-970, Rio Grande do Sul, Brazil.
Stela Maris Meister
SM
Meira
Laboratório de Química do Estado Sólido, Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, Campinas 13083-970, São Paulo, Brazil.
Ana Carolina Mazarin
AC
de Moraes
Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul, Caixa Postal 15.090, Porto Alegre 91501-970, Rio Grande do Sul, Brazil.
Adriano
A
Brandelli
Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, Fortaleza 60455-900, Ceará, Brazil.
Antonio Gomes Souza
AG
Filho
Laboratório de Química do Estado Sólido, Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, Campinas 13083-970, São Paulo, Brazil. Electronic address: oalves@iqm.unicamp.br.
Oswaldo Luiz
OL
Alves
D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010087:Oxides / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012834:Silver / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D010087:Oxides; D012834:Silver; D006108:Graphite
Antibacterial activity; Biofilm; Graphene oxide; Nanocomposites; Pseudomonas aeruginosa; Silver nanoparticles