Jump to main content
Jump to site search

Issue 28, 2017
Previous Article Next Article

‘Overloading’ fluorescent silica nanoparticles with dyes to improve biosensor performance

Author affiliations

Abstract

Using dye-doped silica nanoparticles (DSNP) as reporter probes, we describe a simple method of enhancing fluorescent signal and the extension of the detectable target concentration range in a proof-of-concept ‘dissolution immunoassay’. DSNPs were intentionally ‘overloaded’ with 3% (w/w) FITC such that the high concentration of dye inside the NP core induced self-quenching. Despite exhibiting reduced brightness, the ‘overloaded’ DSNPs were then functionalized with anti-human IgG and were subsequently used to detect human IgG, a model biomarker, in whole serum. Following human IgG recognition, the ‘overloaded’ DSNPs were dissolved using pH 10.6, 0.1 M sodium carbonate–bicarbonate buffer. The large quantity of FITC inside the NP core was consequently released into solution, thus liberating the dyes from self-quenching, and led to a large increase in fluorescein emission intensity. This effect was further enhanced when coupled with FITC's increased quantum yield in basic conditions. The overall result was a 12-fold enhancement in fluorescent signal intensity and an 11-fold improvement in signal-to-noise ratio after a dissolution time of 60 min. In the assay setup presented, the net signal-to-noise ratio for ‘overloaded’ DSNPs was up to 9 times greater following degradation compared to traditionally used 1% (w/w) ‘optimal’ dye-loaded DSNPs. Crucially, this ‘dissolution assay’ strategy using ‘overloaded’ DSNPs could confidently detect human IgG at a 10-fold lower concentration than traditionally used ‘optimal’ DSNPs.

Graphical abstract: ‘Overloading’ fluorescent silica nanoparticles with dyes to improve biosensor performance

Back to tab navigation

Supplementary files

Publication details

The article was received on 11 May 2017, accepted on 26 Jun 2017 and first published on 26 Jun 2017


Article type: Paper
DOI: 10.1039/C7TB01284E
Citation: J. Mater. Chem. B, 2017,5, 5564-5572
  •   Request permissions

    ‘Overloading’ fluorescent silica nanoparticles with dyes to improve biosensor performance

    C. J. Moore, G. Giovannini, F. Kunc, A. J. Hall and V. Gubala, J. Mater. Chem. B, 2017, 5, 5564
    DOI: 10.1039/C7TB01284E

Search articles by author

Spotlight

Advertisements