基于氮掺杂碳量子点荧光猝灭效应检测Fe^(3+)

Detection of Ferric Iron Based on Fluorescence Quenching Effect of N-doped Carbon Quantum Dots

碳量子点光致发光性质取决于尺寸大小和表面官能团的性质。本研究以还原冶炼过程产生的生物质焦油为前驱体,采用小分子乙二胺进行氮掺杂,通过一步水热法合成荧光产率高、分散性能好的氮掺杂碳量子点,基于Fe^(3+)对氮掺杂碳量子点选择性荧光猝灭效应,实现了对Fe^(3+)快速准确检测。合成的氮掺杂碳量子点为规则的球形,尺寸均一,平均粒径为2.64 nm,晶面间距为0.25 nm,具备石墨碳晶格(100)晶格结构,其荧光量子产率为26.1%;Fe^(3+)与N-CQDs表面官能团配位络合致使N-CQDs荧光猝灭,Fe^(3+)浓度在0.23~600μmol/L范围内,与氮掺杂碳量子点荧光猝灭程度呈良好的线性关系,Fe^(3+)的检出限为230 nmol/L。

The photoluminescence properties of carbon quantum dots depend on their size and the properties of surface functional groups.The N-doped carbon dots（using small molecular ethylenediamine） with high quantum yield and excellent dispersibility were synthesized by one-step hydrothermal method with biomass tar that was generated in the reductive smelting process as a precursor.Rapid and accurate Fe^（3＋）detection based on the selective fluorescence quenching effect of N-doped carbon quantum dots was achieved.The results showed that the as-synthesized N-doped carbon quantum dots were regular spherical,uniform in size with an average particle size of 2.64 nm with a quantum yield of 26.1%,and the crystal lattice spacing was 0.25 nm,corresponding to the（100） facet of graphitic carbon structure.The functional groups on the surface of N-doped carbon quantum dots could interact with Fe^（3＋）to form complex compound by coordination,leading to the fluorescence quenching effect.Fluorescence emission ratios kept a linear relationship with the concentrations of Fe^（3＋）in the range of 0.23-600 μmol/L with the detection limit of 230 nmol/L.