resumo
We demonstrate that surface-enhanced Raman scattering (SERS) spectroscopy can be used to monitor variations in the aspect ratio (AR) of colloidal gold nanorods (NRs) during a chemical etching process. The AR of colloidal Au NRs prepared by a seed method was deliberately decreased by addition of aqueous K2S2O8. SERS studies using a 1064 nm laser line revealed a decrease on the detection sensitivity as the nanorods became shorter and using the anion diethyldithiocarbamate (DTC) as the analytical probe. The morphological changes observed for distinct reaction times have also been confirmed by TEM and optical measurements. The dependence of the SERS sensitivity observed for Au NRs of variable AR has been investigated either by using colloids submitted to etching at distinct reaction temperatures or by using a distinct excitation laser line. Therefore, this spectroscopic method offers the possibility to probe in situ changes on the AR of colloidal Au NRs in analytical contexts in which other techniques cannot be easily implemented.
palavras-chave
ENHANCED RAMAN-SCATTERING; SURFACE-PLASMON RESONANCE; ASPECT-RATIO; DITHIOCARBAMATE PESTICIDES; PHOTOTHERMAL THERAPY; AU NANORODS; NANOPARTICLES; SHAPE; SPECTROSCOPY; SPECTRA
categoria
Chemistry; Science & Technology - Other Topics; Materials Science
autores
Fateixa, S; Correia, MR; Trindade, T
nossos autores
Sara Fateixa
Investigador Júnior
Tito Trindade
Professor CatedráticoProjectos
agradecimentos
S. Fateixa thanks Fundacao para a Ciencia e Tecnologia (FCT/FEDER) for the grant SFRH/BD/66460/2009. The authors acknowledge FCT ((PTDC/CTM-NAN/120668/2010, Pest-C/CTM/LA0011/2011), FSE, and POPH for funding. M. Rosario Correia thanks the financial support from Fundacao para a Ciencia e Tecnologia (FCT) through Strategic Project PEst-C/CTM/LA0025/2011 and RECI/FIS-NAN/0183/2012 (FCOMP-01-0124-FEDER-027494).