Raman Signal Enhancement Dependence on the Gel Strength of Ag/Hydrogels Used as SERS Substrates
authors Fateixa, S; Daniel-da-Silva, AL; Nogueira, HIS; Trindade, T
nationality International
journal JOURNAL OF PHYSICAL CHEMISTRY C
keywords KAPPA-CARRAGEENAN; SILVER NANOPARTICLES; TEMPERATURE-DEPENDENCE; HOT-SPOTS; SCATTERING; SPECTROSCOPY; NANOCOMPOSITES; ADSORPTION; 2,2'-DITHIODIPYRIDINE; PARTICLES
abstract A series of hydrogel samples composed of Ag nanoparticles dispersed in carrageenan gels have been prepared and used in SERS studies. These studies demonstrate the dependence of the enhancement of the SERS signal on the strength of the Ag/polysaccharide hydrogel. 2,2'-Dithiodipyridine was used as the analyte probe. Several strategies were employed in order to vary the gel strength. These include the increase of the polysaccharide content in the gel, the addition of KCl as cross-linker, and the variation of the type of carrageenan (kappa, l, lambda) network. An increase in the gel strength originates an increase in the SERS enhancement observed. The results have been interpreted considering hot spots increase due to the formation of Ag particles nanojunctions as the biopolymer matrix tends to rearrange into stronger gels. This is the first report showing that there is a direct correlation between the gel strength of a hydrogel composite used as substrate and its analytical SERS sensitivity.
publisher AMER CHEMICAL SOC
issn 1932-7447
year published 2014
volume 118
issue 19
beginning page 10384
ending page 10392
digital object identifier (doi) 10.1021/jp500301q
web of science category Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary
subject category Chemistry; Science & Technology - Other Topics; Materials Science
unique article identifier WOS:000336198900061

Apoio

1suponsers_list_ciceco.jpg