Premium
Complex concentration dependence of SERS and UV–Vis absorption of glycine/Ag‐substrates because of glycine‐mediated Ag‐nanostructure modifications
Author(s) -
Ojha Animesh K.,
Donfack Patrice,
Materny Arnulf
Publication year - 2012
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.3162
Subject(s) - absorption (acoustics) , chemistry , absorption band , raman scattering , raman spectroscopy , nanostructure , surface plasmon resonance , transmission electron microscopy , analytical chemistry (journal) , absorption spectroscopy , silver nanoparticle , glycine , plasmon , photochemistry , nanoparticle , nanotechnology , materials science , optics , organic chemistry , amino acid , optoelectronics , biochemistry , physics , composite material
Complex concentration‐dependence of surface‐enhanced Raman scattering (SERS) and UV–Vis absorption of Ag‐nanoparticles (AgNPs) mixed with Gly has been observed. Surprisingly, with decreasing Gly concentration, a new band in UV–Vis absorption of AgNPs/Gly mixtures is found to red‐shift with increasing intensity, until a turning point at a critical concentration. Further diluting Gly, the new band blue‐shifts with decreasing intensity. Similarly, the SERS intensities of Gly bands at 615 and 905 cm –1 consistently increase with decreasing Gly concentrations, reaching maxima at the critical concentration. This agrees consistently with the variation in position and intensity of the new developing plasmon absorption band. Interestingly, transmission electron microscopy (TEM) revealed Gly‐induced modifications of AgNPs, including a reassembling and increasing aspect ratio with deceasing Gly concentration. The concentration‐dependent behavior of UV–Vis absorption, SERS, and TEM of AgNPs/Gly mixtures could be due to the complex nature of Gly‐AgNPs interaction depending on the molecular density, as supported by TEM images. Copyright © 2012 John Wiley & Sons, Ltd.