Femtomolar electrochemical detection of DNA hybridization using hollow polyelectrolyte shells bearing silver nanoparticles
Journal article
Authors/Editors
Strategic Research Themes
No matching items found.
Publication Details
Author list: Rijiravanich P., Somasundrum M., Surareungchai W.
Publisher: American Chemical Society
Publication year: 2008
Journal: Analytical Chemistry (0003-2700)
Volume number: 80
Issue number: 10
Start page: 3904
End page: 3909
Number of pages: 6
ISSN: 0003-2700
eISSN: 1520-6882
Languages: English-Great Britain (EN-GB)
View in Web of Science | View on publisher site | View citing articles in Web of Science
Abstract
The preparation, and use as electrochemical labels, of polyelectrolyte shells bearing Ag nanoparticles is described. Their potential for highly sensitive detection is demonstrated. The shells are prepared by layer-by-layer self-assembly around templates (500 nm diameter) which are men dissolved. The shells can be opened and closed by adjustment of solution pH, and this process is utilized to encapsulate Ag nanoparticles, chiefly by adsorption to the inner walls of the capsules. Based on absorbance, TEM and voltammetric measurements, the highest loading achieved is approximately 78 Ag particles per capsule. The Ag capsules are used via biotin-avidin binding as labels for the detection of DNA hybridization, following acid dissolution and then detection of the Ag + by ASV. A 30-mer sequence specific to Escherichia coli is measured at DNA-modified screen-printed electrodes with a detection limit of ∼25 fM, which corresponds to the detection of 4.6 fg (∼3 × 105 molecules) in the 20 μL analyte sample. A 200 fM target containing a single mismatch gives a significandy (<74%) lower response man 200 fM of complementary target; 60 pM of noncomplementary target gives a negligible response. © 2008 American Chemical Society.
Keywords
No matching items found.
Contact Information