Mercury(II) sensing based on the quenching of fluorescence of CdS-dendrimer nanocomposites
Mercury(II) sensing based on the quenching of fluorescence of CdS-dendrimer nanocomposites
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DOI：
10.1039/b914302e
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发表时间：
2009-01-01
期刊：
影响因子：
4.2
通讯作者：
Esteves da Silva, Joaquim C. G.
中科院分区：
文献类型：
--
作者：
Campos, Bruno B.;Algarra, Manuel;Esteves da Silva, Joaquim C. G.
基于硫化镉（CdS）量子点（QDs）表面包覆聚丙烯亚胺（DAB）第5代树枝状大分子（CdS-DAB）纳米复合物的荧光猝灭效应，研制了一种汞（Hg（II））化学传感器。本文报道了CdS-DAB纳米复合材料的合成，并用EDXA、SEM和稳态发光等手段对其进行了表征。通过电子显微镜观察到宏观球形结构，并且最大荧光发射的波长发生在535 nm处（在351 nm处激发）。Stern-Volmer图显示线性响应范围为1 x 10（-6）至1 x 10（-5）M，猝灭常数（K-sv）为1.5 x 10（5）M-1。一个平行因子（PARAFAC）分析模型证实，汞（II）单独挑起淬灭的荧光。Cu（II）和Pb（II）也对CdS-DAB纳米复合物的荧光有猝灭作用，其K-sv分别为1.9 × 10（5）M-1和2.2 × 10（-4）M-1，而Cd（II）、Zn（II）、Co（II）和Ni（II）则没有影响。离子强度在1.25 × 10（-3）到2 M的范围内，会引起发射光谱最大值波长从482 nm移动到677 nm。
A chemical sensor for mercury(II) (Hg(II)) was developed based on the quenching of the fluorescence of cadmium sulfide (CdS) quantum dots (QDs) coated with polypropylenimine tetrahexacontaamine dendrimer ( DAB) generation 5, CdS-DAB nanocomposites. The synthesis and characterization of CdS-DAB nanocomposites by means of EDXA, SEM and steady state luminescence is described. Macroscopic spherical structures are observed by electronic microscopy and the wavelength for the maximum fluorescence emission occurs at 535 nm (excitation at 351 nm). Stern-Volmer plots show a linear response in the range of 1 x 10(-6) to 1 x 10(-5) M with a quenching constant (K-sv) of 1.5 x 10(5) M-1. A parallel factor (PARAFAC) analysis model confirmed that Hg( II) alone provokes quenching of the fluorescence. Cu(II) and Pb(II) also quench the fluorescence of CdS-DAB nanocomposites, with a K-sv = 1.9 x 10(5) M-1 and K-sv = 2.2 x 10(-4) M-1, respectively, and Cd(II), Zn(II), Co(II) and Ni(II) have no effect. Ionic strength, in the range from 1.25 x 10(-3) up to 2 M, provokes a shift in the wavelength of the maximum of the emission spectra, from 482 to 677 nm.