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Ratiometric Fluorescent Test Paper Based on Silicon Nanocrystals and Carbon Dots for Sensitive Determination of Mercuric Ions

Xinfeng Guo, Cui Liu, Nian Li, Shudong Zhang, Zhenyang Wang

R Soc Open Sci. 2018 Jun 27;5(6):171922.

PMID: 30110432

Abstract:

Classical dye absorption-based pH test papers are widely used to measure the degree of acidity of media for quantification or semi-quantification by the observation of the naked eye on the variation of colour. However, it remains a challenging task to extend portable and cheap methods to a wide range of analytes for accurate quantification. Here, we report a dosage-sensitive test paper for the assay of mercury ions (Hg2+) with wide colour evolution. The ratiometric fluorescent probe was prepared by mixing blue-emission silicon nanocrystals (Si NCs) and red-emission carbon dots (r-CDs). The Si NCs serve as the reaction site and the r-CDs as the internal reference. Upon the addition of Hg2+, the blue fluorescence of the Si NCs was quenched, while the red fluorescence of the r-CDs remained constant, resulting in the consecutive fluorescence colour changes from blue to orange red. The probe demonstrates high selectivity and sensitivity of the visualization assay of Hg2+ with a detection limit of 7.63 nM. Moreover, we printed the ratiometric fluorescence probe result onto a piece of filter paper to prepare a test paper, which represents an on-site, sensitive, rapid and cost-effective method for the visual determination of Hg2+ by the naked eye.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
IAR42113 Mercury on Filter Paper Mercury on Filter Paper Price
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