Jump to main content
Jump to site search

Issue 24, 2015
Previous Article Next Article

A dual-mode colorimetric and fluorometric “light on” sensor for thiocyanate based on fluorescent carbon dots and unmodified gold nanoparticles

Author affiliations

Abstract

A novel, highly sensitive and selective dual-readout (colorimetric and fluorometric) sensor based on fluorescent carbon dots (CDs) and unmodified gold nanoparticles (AuNPs) for the detection of thiocyanate (SCN) was proposed. Amino-functionalized CDs could be readily adsorbed onto the surface of citrate-stabilized AuNPs through Au–N interactions, leading to the aggregation of AuNPs and the nonfluorescent off-state of CDs arising from potential fluorescence resonance energy transfer (FRET). However, SCN had a stronger affinity toward AuNPs and could compete with CDs to bind onto the surface of AuNPs in priority, which prevented the aggregation of AuNPs and fluorescence quenching of CDs. Correspondingly, both the colorimetric and fluorometric signals remained “light-on”. The color of the sensing solution remained red and the fluorescence remained unquenched. A distinguishable change in the color was observed at a SCN concentration of 1 μM by the naked eye and a detection limit as low as 0.036 μM was obtained by virtue of fluorescence spectroscopy. Both colorimetric and fluorometric sensors exhibited excellent selectivity toward SCN over other common metallic ions and anions. In addition, such a sensing assay featured simplicity, rapidity, cost-effectiveness and ease of operation without further modification. The accuracy and precision were evaluated based on the quantitative detection of SCN in tap water and saliva samples with satisfactory results.

Graphical abstract: A dual-mode colorimetric and fluorometric “light on” sensor for thiocyanate based on fluorescent carbon dots and unmodified gold nanoparticles

Back to tab navigation

Supplementary files

Publication details

The article was received on 17 Sep 2015, accepted on 30 Oct 2015 and first published on 30 Oct 2015


Article type: Paper
DOI: 10.1039/C5AN01926E
Author version
available:
Download author version (PDF)
Analyst, 2015,140, 8157-8164

  •   Request permissions

    A dual-mode colorimetric and fluorometric “light on” sensor for thiocyanate based on fluorescent carbon dots and unmodified gold nanoparticles

    D. Zhao, C. Chen, L. Lu, F. Yang and X. Yang, Analyst, 2015, 140, 8157
    DOI: 10.1039/C5AN01926E

Search articles by author

Spotlight

Advertisements