title: Spherical gold nanoparticles and gold nanorods for the determination of gentamicin.
abstract: Gentamicin is an antibiotic indicated to treat mastitis in dairy cattle and for the treatment of bacterial resistance in the context of hospital infections. The effect caused by gentamicin on the optical properties of gold nanoparticles aqueous dispersions were used to develop quantitative methods to determine this antibiotic. Two different aqueous dispersions, one containing spherical Au nanoparticles (AuNPs) and the other containing Au nanorods (AuNRs), had their conditions adjusted to enable a stable and sensitive response towards gentamicin. The use of AuNPs, with measurement at 681nm of the rising coupling plasmon band, enabled a limit of detection (LOD) of 0.4ngmL-1(0.02ng absolute LOD), ten times lower than the one achieved by measuring the decreasing of the longitudinal surface plasmon resonance band (at 662nm). The linear analytical response of AuNPs measured at 681nm did not require rationing of signal values to correct for linearity. Stability of the analytical response resulted in intermediary precision below 2%. No significant interference was imposed by excipients traditionally present in injectable solutions for veterinary use. Percent recoveries obtained in such formulations were between 94.5 and 98.2% regardless the existence of any difference in the proportion of the compounds known as gentamicin (C1, C1aand C2) in standard and in the samples. The method requires no derivatization with toxic reagents as usually is required in other spectroscopic approaches.
authors.affiliation: Chemistry Department, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ, Brazil.
authors.forename: Jarol R
authors.initials: JR
authors.lastname: Miranda-Andrades
authors.affiliation: Chemistry Department, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ, Brazil.
authors.forename: Aurora
authors.initials: A
authors.lastname: Pérez-Gramatges
authors.affiliation: Chemistry Department, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ, Brazil.
authors.forename: Omar
authors.initials: O
authors.lastname: Pandoli
authors.affiliation: Physics Department, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900 Rio de Janeiro, RJ, Brazil.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Romani
authors.affiliation: Chemistry Department, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ, Brazil. Electronic address: aucelior@puc-rio.br.
authors.forename: Ricardo Q
authors.initials: RQ
authors.lastname: Aucélio
authors.affiliation: Centro Federal de Educação Tecnológica Celso Suckow da Fonseca-CEFET/RJ, 27600-000 Valença, RJ, Brazil.
authors.forename: Andrea R
authors.initials: AR
authors.lastname: da Silva
mesh_terms: D005839:Gentamicins / Q000032:analysis* / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D013056:Spectrophotometry, Ultraviolet
chemical_list: D005839:Gentamicins; D006046:Gold
keywords: Aminoglycosides; Gentamicin; Gold nanoparticles; Gold nanorods; Localized plasmonic resonance