碳点-二氧化锰纳米复合材料的制备及硫普罗宁的荧光传感

Synthesis of Carbon Dots‑Manganese Dioxide Nanocomposite and Fluorescent Sensing of Tiopronin

以聚烯丙胺盐酸盐为反应底物,通过一步水热法制备了荧光碳点(CDs)并在其中引入高锰酸钾,通过原位的氧化还原反应制备了CDs‑MnO_(2)纳米复合材料。通过透射电子显微镜、X射线光电子能谱、纳米粒度分析、紫外-可见吸收光谱、荧光光谱、荧光寿命对其进行了形貌、结构、成分、发光性能的表征。结果表明,MnO_(2)通过静态猝灭效应(SQE)和内滤效应(IFE)猝灭了CDs的荧光。进一步,由于硫普罗宁(TPN)分子中的活性巯基与MnO_(2)的特异性反应使得MnO_(2)降解,猝灭剂消失,进而使得荧光恢复。基于此,我们建立了基于CDs‑MnO_(2)的荧光传感模式来测定TPN的新方法,该方法对TPN表现出良好的灵敏度和选择性,线性范围为0.2~80μmol·L^(-1),检出限为0.11μmol·L^(-1)。该MnO_(2)纳米材料调控的荧光检测法用于尿液样品的测定,回收率为97.57%~102.58%。

Herein,fluorescent carbon dots(CDs)were synthesized through a hydrothermal method using poly(allylamine hydrochloride)as reaction substrate.After introduce of potassium permanganate,CDs‑MnO_(2) nanocomposite were prepared through an in situ redox reaction.The as‑prepared nanomaterials were characterized by transmission electron microscope,X‑ray photoelectron spectroscopy,nanometer size analysis,ultraviolet‑visible absorption spectrum,fluorescence spectrum,and fluorescence lifetime.It was demonstrated that the MnO_(2) quenched the fluorescence intensity of CDs through static quenching effect(SQE)and inner filter effect(IFE).Further,taking advantage of active thiol in its molecule,tiopronin(TPN)decomposed MnO_(2) through a unique redox reaction,which made the quencher disappeared and thus restored the fluorescence.Therefore,a CDs‑MnO_(2) nanocomposite based fluorescent sensor was established to detect tiopronin.This method showed good sensitivity and selectivity for TPN.The linear range was 0.2~80μmol·L^(-1) with a detection limit of 0.11μmol·L^(-1).The MnO_(2) nanomaterials mediated fluorescence method was applied for the TPN detection in urine sample and the recovery was in the range of 97.57%~102.58%.