摘要
以手性化合物D-青霉胺和L-半胱氨酸为双修饰剂在水相中合成了CdSe纳米晶,痕量Hg(Ⅱ)对其荧光强度有明显猝灭作用,基于此建立了定量测定痕量Hg(Ⅱ)的新方法。在Cd2+,HSe-,D-Pen和L-Cys摩尔比为1∶0.25∶2∶1.2,pH=7.5的条件下,合成的纳米晶具有更好的发光强度和稳定性。TEM显示CdSe纳米晶为球形颗粒,粒径约为50和80nm。在磷酸盐缓冲溶液(pH7.38)中,CdSe纳米晶最大荧光峰为516nm,对Hg(Ⅱ)有高选择性响应。纳米晶的相对荧光强度与Hg(Ⅱ)的浓度呈良好线性关系,检出限为40pmol/L。本方法测定不同水样中Hg(Ⅱ)的浓度,回收率为96.7%～102.5%。
Dual-stabilizer （D-Penicillamine （D-Pen） and L-Cysteine （L-Cys） ） capped CdSe nanocrystals were prepared by direct aqueous synthesis method,and trace Hg（Ⅱ） have a significantly quenched their fluorescence intensity.A new method for the determination of trace Hg（Ⅱ） was established based on this.When pH is 7.5 and molar ratio of Cd2 ＋∶HSe-∶D-Pen∶L-Cys is 1∶0.25∶2∶1.2,CdSe/D-Pen/L-Cys has a better luminescent strength and stability than CdSe/D-Pen and CdSe/L-Cys.TEM shows that the CdSe nanocrystals are spherical particles,and the sizes of the particles are about 50 nm and 80 nm,respectively.In the phosphate buffer solution at pH 7.38,maximum fluorescence peak of CdSe/D-Pen/L-Cys was at 516 nm,the fluorescence could be quenched significantly and selectively by Hg（Ⅱ） .The fluorescence quenching was proportional to the concentration of Hg（Ⅱ）,a detection limit of 40 pmol/L was achieved.The method was applied to the determination of Hg（Ⅱ） in different water samples,and the results were in a good agreement with those obtained by the standard method.The average recovery was 96.7%-102.5% .
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2010年第10期1405-1410,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(No.20975041)
广东省自然科学基金(No.7005803)资助项目
关键词
CDSE纳米晶
D-青霉胺
L-半胱氨酸
汞
荧光猝灭
Cadmium selenide nanocrystals
D-Penicillamine
L-Cysteine
Mercury（Ⅱ）
Fluorescence quenching
