Dual Enlargement of Gold Nanoparticles: From Mechanism to Scanometric Detection of Pathogenic Bacteria

Cuong Cao, Lionel Cervera Gontard, Tram Thuy Le Ly, Anders Wolff, Dang Duong Bang

    Research output: Contribution to journalJournal articleResearchpeer-review


    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.
    Original languageEnglish
    Issue number12
    Pages (from-to)1701-1708
    Publication statusPublished - 2011


    Dive into the research topics of 'Dual Enlargement of Gold Nanoparticles: From Mechanism to Scanometric Detection of Pathogenic Bacteria'. Together they form a unique fingerprint.

    Cite this