Ultrasensitive Copper(II) Detection Using Plasmon-Enhanced and Photo-Brightened Luminescence of CdSe Quantum Dots
Ultrasensitive Copper(II) Detection Using Plasmon-Enhanced and Photo-Brightened Luminescence of CdSe Quantum Dots
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DOI：
10.1021/ac902985p
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发表时间：
2010-05-01
影响因子：
7.4
通讯作者：
Batteas, James D.
中科院分区：
文献类型：
--
作者：
Chan, Yang-Hsiang;Chen, Jixin;Batteas, James D.
在这里，我们提出了一个简单的平台，使用16-巯基十六烷酸（16-MHA）覆盖的CdSe量子点（QDs）作为超灵敏铜（II）检测的探针。在本研究中，量子点的光致发光（PL）首先通过在Si表面自组装的Ag纳米棱镜增强，然后通过光增亮进一步增强。使用这种方法，对照物和不同的分析物可以很容易地在一个平台上使用荧光显微镜进行探测。在Cu2+的存在下，CdSe量子点的PL强度增强被选择性猝灭，同时出现了新的红移发光带。经x射线光电子能谱（XPS）测量证实，该猝灭机理为阳离子交换机制。在此，我们证明了这种简单的方法可以提供快速可靠的Cu2+检测，检测限低至5 nM，动态范围高达100 μ M，固定快速反应时间为5 min。在混合离子溶液和生理液体两种方法中测试了该技术的潜在应用，两种实验都显示出对Cu2+的良好选择性。
Here, we present a simple platform for the use of the enhanced emission of 16-mercaptohexadecanoic acid (16-MHA) capped CdSe quantum dots (QDs) as a probe for ultrasensitive copper(II) detection. In this study, the photoluminescence (PL) of the QDs was first enhanced by Ag nanoprisms which were self-assembled on Si surfaces and then further increased by photobrightening. Using this approach, the control and different analytes could be readily probed all on a single platform using fluorescence microscopy. The enhanced PL intensity of CdSe QDs was selectively quenched in the presence of Cu2+, accompanied by the emergence of a new red-shifted luminescence band. The quenching mechanism was found to be due to a cation exchange mechanism as confirmed by X-ray photoelectron spectroscopy (XPS) measurements. Herein, we have demonstrated that this simple methodology can offer a rapid and reliable detection of Cu2+ with a detection limit as low as 5 nM and a dynamic range up to 100, mu M in a fixed fast reaction time of 5 min. The potential applications of this technique were tested in two ways, for mixed-ion solutions and in physiological fluids, and both experiments exhibited good selectivity toward Cu2+.