skip to main content

SciTech ConnectSciTech Connect

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

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.
Authors:
; ; ; ; ;  [1]
  1. College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China)
Publication Date:
OSTI Identifier:
22250795
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 4; Journal Issue: 3; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION SPECTRA; ADSORPTION; ATOMIC FORCE MICROSCOPY; COLLOIDS; CRYSTALS; GOLD; NANOSTRUCTURES; PARTICLES; PH VALUE; SENSORS; SOLUTIONS; SPECTROSCOPY; SUBSTRATES