水相合成CdTe量子点测定海藻中微量碲

Determination of trace tellurium in seaweed by aqueous synthesis of CdTe quantum dots

以亚碲酸钠(Na;TeO;)为Te源,CdCl;为Cd源,水合肼(SHJ)为还原剂,3-巯基丙酸(3-MPA)为稳定剂,制得λ;=380 nm和λ;=608 nm的CdTe量子点(CdTe QDs),该量子点的荧光强度与合成前Na;TeO;浓度呈线性关系。在n(Cd)/n(SHJ)=1:0.04,n(Cd)/n(3-MPA)=1:2.7,温度为100℃,反应时间为120 min,溶液pH 10.5的最佳条件下,可制备荧光量子产率为65%的CdTe QDs,该量子点的荧光强度与含碲物质的浓度符合较宽的线性范围(1.0~300μmol/L),相关系数为0.9982,检测限为38 nmol/L。方法用于测定微波消解下的海藻样品,加标回收率为106.0%~112.0%,RSD为5.4%~6.1%。

CdTe quantum dots(QDs)(λ;= 380 nm, λ;= 608 nm) were synthesized by reaction of sodium tellurite(Na;TeO;) and cadmium chloride with hydrazine hydrate(SHJ) as the reductant and thioglycolic acid(MPA) as the stabilizer.The fluorescence intensity of the synthesized quantum dots was linearly related to the initial concentration of sodium tellurite(Na;TeO;) in the synthesis system. Based on the experiment, the optimal synthetic conditions were as follows: n(Cd)/n(SHJ) = 1:04, n(Cd)/n(3-MPa) = 1:2.7, temperature of 100℃, reaction time of 120 min and pH 10.5. CdTeQDs with a fluorescence quantum yield of 65% can be prepared. The fluorescence intensity of CdTeQDs corresponds to the concentration of tellurium substances in a wide linear range(1.0-300 μmol/L), and the correlation equation was I = 2263.6c + 7.81 with the correlation(r;) of 0.9982 and limit of detection of 38 nmol/L. The method was applied in analysis of trace tellurium in seaweed after microwave digestion, the recoveries were 106.0%-112.0%, and the RSDs were 5.4%-6.1%.