【摘要】 以CdTe量子点为荧光探针,基于荧光猝灭法对Ag(Ⅰ)和Ca(Ⅱ)进行了定量检测.考察了缓冲液的浓度、缓冲液pH值、反应时间等多种因素的影响.结果表明:(1)在浓度为10～20 mmol/L、pH值为7～8的磷酸二氢钠-磷酸氢二钠缓冲液中,Ag+与量子点反应时间为20 min时,量子点荧光衰减程度(ΔF)与Ag+浓度呈现良好的线性关系,线性区间为2.5×10-7～2.75×10-6mol/L,检测限为2.2×10-7mol/L.水溶性的CdTe量子点对Ag+具有高度选择性,可以作为一种新型的Ag+离子选择性荧光探针.(2)在浓度为1～2 mmol/L、pH值为7～8的磷酸二氢钠-磷酸氢二钠缓冲液中,Ca2+与量子点反应时间为25 min时,量子点荧光衰减程度(ΔF)与Ca2+浓度呈现良好的线性关系,线性区间为7.5×10-4～3×10-3mol/L,检测限为2.08×10-4mol/L.为Ca(Ⅱ)的测定提供了新的方法.更多还原

【Abstract】 A new approach was developed for the sensitive and selective determination of Ag(Ⅰ)and Ca(Ⅱ)with CdTe quantum dots(QDs)as fluorescent probes.Different influencing factors were studied,including the concentration and pH of buffer solution,and reacting time.The results indicated that in a 10 to 20 mmol/L NaH2PO4-Na2HPO4 buffer solution with pH value of 7 to 8,when the reacting time was 20 minutes,the magnitude of decrease in fluorescence intensity went through a well linear change with the concentration of silver(Ⅰ)in the range of 2.5×10-7～2.75×10-6 mol/L.The obtained linear fitting equation is:F0-F=-3.1225+0.1435 C(10-8 mol/L)with the correlation coefficient of 0.99852 and the detection limitation is 2.2×10-7 mol/L.Water-soluble CdTe QDs were selective to silver ions and might be used as a novel selective fluorescence probe for silver ions.In a 1 to 2 mmol/L NaH2PO4-Na2HPO4 buffer solution with pH 7 to 8,when the reacting time was 25 minutes,the magnitude of decrease in fluorescence intensity went through a well linear change with the concentration of calcium(Ⅱ)in the range of 7.5×10-4～3×10-3 mol/L.The obtained linear fitting equation is:F0-F=-0.6564+0.26649 C(10-5 mol/L)with the correlation coefficient of 0.95998 and the detection limitation is 2.08×10-4 mol/L.The results in this work indicate that CdTe QDs can act as a new luminescent probe for detecting calcium ions.更多还原