Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, China) School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Mikrochim Acta. 2019 Nov 15;186(12):779. doi: 10.1007/s00604-019-3990-8.
A non-enzymatic fluorometric assay is described for the determination of glucose. The method is based on the use of g-CN quantum dots (QDs) that have good water solubility. The QDs were synthesized by a one-step solvothermal process using formamide as precursor. The QDs possess an average size of 5 nm, a band gap of 3.03.5 eV, and strong blue fluorescence (with excitation/emission maxima at 400/447 nm). Fluorescence is quenched by glucose (which acts as the electron acceptor) via an electron transfer mechanism. Comprehensive spectroscopy and density functional theory calculations show that the selectivity of the fluorescent probe can be attributed to the presence of N-H bonds that are formed between the QDs (mainly at plane edges) and glucose. The interaction forces lead to the formation of localized states for capturing hot electrons. This results in a decrease in the band gap and a reduction in fluorescence intensity. The probe is selective over some typical interfering species (such as cysteine and albumin) which often are present in the urine of diabetics. The method has a linear response in the 0.2 to 5.0 mM glucose concentration range and a 0.2 mM detection limit. Graphical abstractSchematic representation of the synthesis of g-CN quantum dots (QDs) as a fluorescent nanoprobe for selective detection of glucose.
一种用于测定葡萄糖的非酶荧光分析方法。该方法基于使用具有良好水溶性的 g-CN 量子点 (QD)。QD 通过一步溶剂热法使用甲酰胺作为前体制备。QD 的平均尺寸约为 5nm，带隙为 3.0-3.5eV，具有很强的蓝色荧光（激发/发射最大值在 400/447nm）。荧光通过电子转移机制被葡萄糖（作为电子受体）猝灭。综合光谱和密度泛函理论计算表明，荧光探针的选择性可归因于 QD（主要在平面边缘）与葡萄糖之间形成的 N-H 键。相互作用力导致捕获热电子的局域态的形成。这导致带隙减小和荧光强度降低。该探针对一些常见的干扰物质（如半胱氨酸和白蛋白）具有选择性，这些物质通常存在于糖尿病患者的尿液中。该方法在 0.2 至 5.0mM 葡萄糖浓度范围内具有线性响应，检测限为 0.2mM。
