ABSTRACT
An ultra-sensitive spectrofluorimetry method was developed and validated for the rapid determination of ferrocyanide ions (hexacyanidoferrate(II), FeCN64-, FCNs) by using sulphur (S) and nitrogen (N) dual-doped fluorescence carbon nanoparticles (S,N-FCNPs) as nanoprobe. The fluorescence of S,N-FCNPs was strongly reduced due to the dynamic interaction between S,N-FCNPs and FeCNs. The developed method proved to be highly sensitive and selective for FeCNs detection with linearity in three concentration ranges over four orders of magnitude, covering 0.01–200.0 μg/mL.
A limit of detection (LOD) of 2.8 ng/mL was obtained. The method was successfully applied for the determination of FeCNs in a series of dietary food salt samples and gave satisfactory results; the spiked recoveries were 97.6‒104.6% with standard uncertainty less than 5.8%. The method proved to be applicable for ultra-trace detection of FeCNs in food salt samples, having advantages in great simplicity, rapid response, low cost, favourable selectivity, and high sensitivity.
Graphical Abstract
Acknowledgments
This work was supported by the LvYang Golden Phoenix Plan, Yangzhou City (2019), China Postdoctoral Science Foundation [2020M671625]; National Natural Science Foundation of China [21922202]; Yangzhou Key R&D Project (Social Development), China (2020) [YZ2020063]; Natural Science Fund for Colleges and Universities in Jiangsu Province, China [19KJB150042]; Yangzhou University Technology Innovation Cultivation Fund [2019CXJ188]; Opening Foundation of Jiangsu Dairy Bioengineering Technology Research Center [KYRY2019002].
Disclosure statement
No potential conflict of interest was reported by the authors.
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