基于绿色合成的掺杂型荧光碳点用于检测环境水样和生物体中磷酸根和桑色素

Green synthesis of doped fluorescent carbon dots for the detection of p phate and morin in environmental water samples and living organisms

以葡萄糖为碳源,间苯二胺为掺杂剂,通过一步水热法在无添加任何有机溶剂的条件下绿色合成量子产率16.6%的绿色荧光碳点(NCDs)。对NCDs的粒径、形貌及表面官能团进行了表征,发现NCDs为球形并具有明显的晶格条纹;表面富含羟基(-OH)、羧基(-COOH)和亚胺基(-NH)等亲水基团。荧光光谱显示,NCDs具有激发依赖性。通过紫外吸收光谱、荧光衰减曲线及不同温度下猝灭常数的变化,确定磷酸根(PO_(4)^(3-))对NCDs的猝灭机制属于动态猝灭。NCDs检测PO_(4)^(3-)的线性范围是0.1~10μmol/L,检出限为39.4 nmol/L;桑色素对NCDs的猝灭机制为内滤效应和静态猝灭的协同作用,NCDs对桑色素的检测线性范围是0.1~15μmol/L,检出限低至44.8 nmol/L。对环境水样和生物样品中PO_(4)^(3-)和桑色素进行测定,加标回收率在96.2%~104.4%之间。

Green emitting fluorescent carbon dots(NCDs)with quantum yield of 16.6%were successfully synthesized by one-step hydrothermal method using glucose as carbon source and m-phenylenediamine as dopant without adding any organic solvent.The particle size,morphology,and surface functional groups of NCDs were characterized,and it was found that NCDs were spherical with obvious lattice stripes.The surfaces of NCDs are rich in hydrophilic groups such as-OH,-COOH and-NH.Fluorescence spectroscopy showed that NCDs exhibited excitation dependence.The quenching mechanism of PO_(4)^(3-)on NCDs was determined by UV absorption spectroscopy,fluorescence decay curve,and changes in quenching constants at different temperatures,which belonged to dynamic quenching.The linear range for the detection of PO_(4)^(3-)was 0.1-10μmol/L with a detection limit of 39.4 nmol/L.The quenching mechanism of morin on NCDs was a combination of internal filtration effect and static quenching.The linear range of morin was 0.1-15μmol/L with a detection limit as low as 44.8 nmol/L.The spiked recoveries for the detection of PO_(4)^(3-)and morin in environmental water and biological samples were96.2%-104.4%.