Department of Engineering and System Science, Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, 115, Taiwan.
Mikrochim Acta. 2019 Feb 9;186(3):166. doi: 10.1007/s00604-019-3277-0.
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. Graphical abstract Schematic presentation of the polyethylenimine (PEI) carbon nanodots (C-dots) as a fluorescent probe for uric acid. Their fluorescence is quenched by periodate (IO) due to oxidative formation of nitrone groups, an subsequently restored due to reduction by uric acid (UA).
稳定且低成本的碳点（C-dots）可通过水热法由聚乙烯亚胺（PEI）制备。研究发现，C-dots 的荧光（最佳激发/发射波长为 365/473nm）会被高碘酸盐选择性氧化表面的 PEI 而猝灭，但在尿酸（UA）存在的情况下会恢复。据推测，这是由于 UA 将硝酮基团选择性还原为羟胺基团。该发现被用于设计一种荧光法测定 UA，其检测限为 2.3nM。这低于已报道的荧光法和酶法测定。该方法的性能已通过测定人唾液样本中的 UA 得到验证。结果发现，与商业 UA 测定法的结果吻合良好。示意图呈现了聚乙烯亚胺（PEI）碳纳米点（C-dots）作为尿酸的荧光探针。由于硝酮基团的氧化形成，它们的荧光被高碘酸盐（IO）猝灭，随后由于尿酸（UA）的还原而恢复。
