Water-dispersed silicon quantum dots for on-off-on fluorometric determination of chromium(VI) and ascorbic acid
- 107 Downloads
Water-dispersed silicon quantum dots (SiQDs) with the quantum yield of 25% was prepared using aminopropyltrimethoxysilane as the silicon source and ascorbic acid (AA) as the reduction reagent. The SiQDs display blue fluorescence with excitation/emission peaks at 350 nm/440 nm. The synthesized SiQDs are shown to be a viable “on-off-on” fluorescent probe for the detection of Cr(VI) and AA. Cr(VI) ions exert an inner filter effect on the fluorescence of the SiQDs which results in a reduction of fluorescence (off-state). On addition of AA, Cr(VI) is chemically reduced to Cr(III) which weakens the inner filter effect and restores fluorescence (on-state). The method has low detection limits for both Cr(VI) and AA (0.16 μM and 0.57 μM, respectively). It was applied to the analysis of spiked lotus seeds and human serum samples.
KeywordsSilicon quantum dots Ascorbic acid Fluorescent nanoprobe Cr(VI)
This project was financially supported by NSFC (81773894, 81872990 and 21305014), the Natural Sciences Foundation of Fujian Province (2018 J01871, 2016 J01396). Huifeng Xu also thanks the Natural Science Funds of Fujian Province for Distinguished Young Scholar (2019 J06021). Wen Xu also thanks the School Supervision Subject of Fujian University of Traditional Chinese Medicine (X2017010, Chen Zhongwei).
Compliance with ethical standards
The author(s) declare that they have no competing interests.
- 2.Zhong Y, Peng F, Bao F, Wang S, Ji X, Yang L, Su Y, Lee ST, He Y (2013) Large-scale aqueous synthesis of fluorescent and biocompatible silicon nanoparticles and their use as highly photostable biological probes. J Am Chem Soc 135(22):8350–8356. https://doi.org/10.1021/ja4026227 CrossRefPubMedGoogle Scholar
- 6.Hu Z, Tan J, Lai Z, Zheng R, Zhong J, Wang Y, Li X, Yang N, Li J, Yang W, Huang Y, Zhao Y, Lu X (2017) Aptamer combined with fluorescent silica nanoparticles for detection of hepatoma cells. Nanoscale Res Lett 12(1):96–103. https://doi.org/10.1186/s11671-017-1890-6 CrossRefPubMedPubMedCentralGoogle Scholar
- 8.Luo L, Song Y, Zhu C, Fu S, Shi Q, Sun Y-M, Jia B, Du D, Xu Z-L, Lin Y (2018) Fluorescent silicon nanoparticles-based ratiometric fluorescence immunoassay for sensitive detection of ethyl carbamate in red wine. Sensor Actuat B-Chem 255:2742–2749. https://doi.org/10.1016/j.snb.2017.09.088 CrossRefGoogle Scholar
- 20.Rong M, Lin L, Song X, Wang Y, Zhong Y, Yan J, Feng Y, Zeng X, Chen X (2015) Fluorescence sensing of chromium (VI) and ascorbic acid using graphitic carbon nitride nanosheets as a fluorescent “switch”. Biosens Bioelectron 68:210–217. https://doi.org/10.1016/j.bios.2014.12.024 CrossRefPubMedGoogle Scholar
- 23.Zhao P, He K, Han Y, Zhang Z, Yu M, Wang H, Huang Y, Nie Z, Yao S (2015) Near-infrared dual-emission quantum dots–gold nanoclusters Nanohybrid via co-template synthesis for Ratiometric fluorescent detection and bioimaging of ascorbic acid in vitro and in vivo. Anal Chem 87(19):9998–10005. https://doi.org/10.1021/acs.analchem.5b02614 CrossRefPubMedGoogle Scholar