Journal article
Dual Enlargement of Gold Nanoparticles: From Mechanism to Scanometric Detection of Pathogenic Bacteria
National Veterinary Institute, Technical University of Denmark1
Center for Electron Nanoscopy, Technical University of Denmark2
Department of Micro- and Nanotechnology, Technical University of Denmark3
Section of Poultry Diseases, Division of Poultry, Fish and Fur Animals, National Veterinary Institute, Technical University of Denmark4
Division of Poultry, Fish and Fur Animals, National Veterinary Institute, Technical University of Denmark5
A mechanism of dual enlargement of gold nanoparticles (AuNPs) comprising two steps is described. In the first step, the AuNPs are enlarged by depositing Au atoms on their crystalline faces. In this process, the particles are not only enlarged but they are also observed to multiply: new Au nuclei are formed by the budding and division of the enlarged particles.
In the second step, a silver enhancement is subsequently performed by the deposition of silver atoms on the enlarged and newly formed AuNPs to generate bimetallic Au@Ag core–shell structures. The dual nanocatalysis greatly enhances the electron density of the nanostructures, leading to a stronger intensity for colorimetric discrimination as well as better sensitivity for quantitative measurement.
Based on this, a simple scanometric assay for the on‐slide detection of the food‐born pathogen Campylobacter jejuni is developed. After capturing the target bacteria, gold‐tagged immunoprobes are added to create a signal on a solid substrate. The signal is then amplified by the dual enlargement process, resulting in a strong color intensity that can easily be recognized by the unaided eye, or measured by an inexpensive flatbed scanner.
In this paper, dual nanocatalysis is reported for the first time. It provides a valuable mechanistic insight into the development of a simple and cost‐effective detection format.
Language: | English |
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Publisher: | WILEY‐VCH Verlag |
Year: | 2011 |
Pages: | 1701-1708 |
ISSN: | 16136829 and 16136810 |
Types: | Journal article |
DOI: | 10.1002/smll.201100294 |
ORCIDs: | Wolff, Anders and Bang, Dang Duong |