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Influence of the pH value of a colloidal gold solution on the absorption spectra of an LSPR-assisted sensor

Authors :
Jin Zhu
Wenbin Li
Mao Zhu
Wei Zhang
Wencheng Niu
Guohua Liu
Source :
AIP Advances, Vol 4, Iss 3, Pp 031338-031338-6 (2014)
Publication Year :
2014
Publisher :
AIP Publishing LLC, 2014.

Abstract

The localized surface plasmon resonances (LSPRs) of gold particles assembled on a crystal plate are a powerful tool for biological sensors. Here, we prepare gold colloids in different pH solutions. We monitor the effects of the particle radius and particle coverage on the absorption spectra of AT-cut (r-face dihedral angle of about 3°) crystal plates supporting gold nanoparticles. The surface morphologies were monitored on silicon dioxide substrates using ultraviolet and visible (UV-vis) spectroscopy, and atomic force microscopy (AFM). The results showed that the gold particle coverage decreases with increasing pH value of the gold colloid solution. This phenomenon demonstrates that self-assembled gold surfaces were formed via the electrostatic adsorption of gold particles on the positively charged, ionized amino groups on the crystal plates in the acidic solution. The spectrum of gold nanoparticles with different coverage degree on the crystal plates showed that the LSPR properties are highly dependent on pH.

Subjects

Subjects :
Physics
QC1-999

Details

Language :
English
ISSN :
21583226
Volume :
4
Issue :
3
Database :
Directory of Open Access Journals
Journal :
AIP Advances
Publication Type :
Academic Journal
Accession number :
edsdoj.8f28117e26684fc09ec232f7c15c60e9
Document Type :
article
Full Text :
https://doi.org/10.1063/1.4869615