西蓝花茎叶氮、硫和硅掺杂的碳量子点对敌敌畏的快速检测方法构建

Rapid Detection of Dichlorvos Using Nitrogen,Sulfur and Silicon Doped Carbon Quantum Dots Derived from Stems and Leaves of Broccoli

为实现食品中敌敌畏的快速、准确检测,以废弃的西蓝花茎叶作为前体,水热碳化法绿色制备了氮、硫、硅掺杂的碳量子点(carbon quantum dots,CDs),采用动态光散射、X射线衍射以及X射线光电子能谱等手段对其进行结构表征以及元素分析。进一步依据酶抑制反应原理,构建了CDs/Fe^(2+)/乙酰胆碱酯酶反应检测体系,并将所制备的荧光传感器运用于有机磷农药的检测。结果表明,新型CDs具有石墨烯结构,其量子产率约为9.53%,兼具良好的水溶解性以及光致发光性,测得其粒径约为30 nm,其表面氮、硫、硅元素存在,且含有氧和氮为主的功能性官能团。将所制备的荧光传感器运用于有机磷农药的检测,敌敌畏的检出限约为8 ng/mL。最后将所制备的氧化还原型CDs/Fe^(2+)荧光探针,应用于实际商业食品中敌敌畏的检测,结果表明样品的加标回收率范围大致为90%~97%,相对标准偏差不超过1%(n=3)。证实了该探针在实际样品检测中的可实用性和准确性,也表明所制备的CDs/Fe^(2+)氧化还原型荧光探针未来用于生物和食品领域中的有机磷农药检测有着广阔的前景。

Using waste broccoli stems and leaves as the precursor,nitrogen,sulfur and silicon doped carbon quantum dots(CDs)were prepared by hydrothermal carbonization method,and their structural characterization and element analysis were conducted by dynamic light scattering(DLS),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).Furthermore,according to the principle of enzyme inhibition,a CDs/Fe^(2+)/acetylcholinesterase reaction system was constructed and used to fabricate a fluorescence sensor to detect organophosphorus pesticides.The results showed that the new CDs had a graphene-like structure,with a quantum yield of 9.53%and good water solubility and photoluminescence properties.The particle size was measured to be about 30 nm,nitrogen,sulfur and silicon were found to be present in the surface of CDs,and the dots contained functional groups dominated by oxygen and nitrogen.The limit of detection(LOD)of the fluorescence sensor for dichlorvos was about 8 ng/mL.Finally,the oxidized/reduced CDs/Fe^(2+)fluorescent probe was applied to the determination of dichlorvos in commercial foods.The results showed that the recoveries for the spiked samples ranged from 90%to 97%with relative standard deviation(RSD)not larger than 1%(n=3),indicating the practicality and accuracy of the probe.The CDs/Fe^(2+)fluorescent probe has a broad prospect for the detection of organophosphorus pesticides in the fields of biology and food in the future.