Nitrogen-doped carbon nanodots prepared from polyethylenimine for fluorometric determination of salivary uric acid
Stable and low-cost carbon dots (C-dots) were prepared from polyethylenimine (PEI) by a hydrothermal method. It is found that the fluorescence of the C-dots (best measured at excitation/emission wavelengths of 365/473 nm) is quenched by selective oxidation of surface PEI by periodate but recovers in the presence of uric acid (UA). It is assumed that this is due to the selective reduction of the nitrone groups to hydroxylamine groups by UA. The findings were used to design a fluorometric method for determination of UA that has a 2.3 nM detection limit. This is lower than that of reported fluorometric and enzymatic assays. The performance of the method has been validated by determination of UA in samples of human saliva. It is found that the results agree well with those obtained by a commercial UA assay.
KeywordsAntioxidant C-dots Hydrothermal synthesis Periodate Nitrone Uricase
We would like to thanks the financial support from MOST, Taiwan by the project: 104-2221-E-007-072-MY3, 104-2321-B-007-003, 103-2321-B-007-004, 104-2113-M-002-008-MY3, 104-2923-M-002-006-MY3, 106-2622-M-002-001-CC2 and EXCELLENCE UNIVERSITY CENTER PROJECT FOR BIOMEDICAL TECHNOLOGY, NTHU, 2013-2016. This work was also financially supported by the Frontier Research Center on Fundamental and Applied Sciences of Matters, from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE 107QR001I5), Taiwan.
Compliance with ethical standards
The author(s) declare that they have no competing interests.
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