| Título: | Ultrasensitive Pb2+ detection by glutathione-capped quantum dots |
| Autores: | ALI, EMRIL MOHAMED ; ZHENG, YUANGANG ; YU, HSIAO-HUA ; YING, JACKIE Y. |
| Tipo de documento: | texto impreso |
| ISBN/ISSN/DL: | 41340 |
| Nota general: | ISBN: |
| Langues: | Inglés |
| Clasificación: | |
| Resumen: | Water-soluble and stable quantum dots (QDs), CdTe and CdZnSe, are applied for ultrasensitive Pb2+ detection. These QDs are capped with glutathione (GSH) shells. GSH and its polymeric form, phytochelatin, are employed by nature to detoxify heavy metal ions. As a result of specific interaction, the fluorescence intensity of GSHcapped QDs is selectively reduced in the presence of heavy metal ions such as Pb2+. The detection limit of Pb2+ is found to be 20 nM due to the superior fluorescence properties of QDs. Detailed studies by spectroscopy, microscopy, and dynamic light scattering show that competitive GSH binding of Pb2+ with the QD core changed both the surface and photophysical properties of the QDs. Fluorescence of QDs is quenched, and QD aggregation occurs. Coupling the GSH-capped QDs with a highthroughput detection system, we have developed a simple scheme for quick and ultrasensitive Pb2+ detection without the need for additional electronic devices. In the presence of ionic mixtures, our system is still capable of Pb2+ detection with a detection limit as low as 40 nM. The system only becomes less sensitive when the ionic mixture is present at a very high concentration (i.e., g50 íM). |
| Nota de contenido: | En: Analytical Chemistry. -- (79) : 9452-9458 (2007) |
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