Open AccessRatiometric fluorescent test paper based on silicon nanocrystals and carbon dots for sensitive determination of mercuric ions
Author(s) -
Xiaoxia Guo,
Cui Liu,
Nian Li,
Zhenyang Wang
Publication year - 2018
Publication title -
royal society open science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 51
ISSN - 2054-5703
DOI - 10.1098/rsos.171922
Subject(s) - naked eye , fluorescence , detection limit , analyte , ion , analytical chemistry (journal) , materials science , chemistry , nanocrystal , carbon fibers , photochemistry , nanotechnology , optics , chromatography , physics , organic chemistry , composite number , composite material
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 (Hg 2+ ) 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 Hg 2+ , 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 Hg 2+ 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 Hg 2+ by the naked eye.