Iodide-Responsive Cu鈥揂u Nanoparticle-Based Colorimetric Platform for Ultrasensitive Detection of Target Cancer Cells
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- 作者：Xiaosheng Ye ; Hui Shi ; Xiaoxiao He ; Kemin Wang ; Dinggeng He ; Lv鈥檃n Yan ; Fengzhou Xu ; Yanli Lei ; Jinlu Tang ; Yanru Yu
- 刊名：Analytical Chemistry
- 出版年：2015
- 出版时间：July 21, 2015
- 年：2015
- 卷：87
- 期：14
- 页码：7141-7147
- 全文大小：374K
- ISSN：1520-6882
文摘
Colorimetric analysis is promising in developing facile, fast, and point-of-care cancer diagnosis techniques, but the existing colorimetric cancer cell assays remain problematic because of dissatisfactory sensitivity as well as complex probe design or synthesis. To solve the problem, we here present a novel colorimetric analytical strategy based on iodide-responsive Cu鈥揂u nanoparticles (Cu鈥揂u NPs) combined with the iodide-catalyzed H2O2鈥揟MB (3,3,5,5-tetramethylbenzidine) reaction system. In this strategy, bimetallic Cu鈥揂u NPs prepared with an irregular shape and a diameter of 鈭?5 nm could chemically absorb iodide, thus indirectly inducing colorimetric signal variation of the H2O2鈥揟MB system. By further utilizing its property of easy biomolecule modification, a versatile colorimetric platform was constructed for detection of any target that could cause the change of Cu鈥揂u NPs concentration via molecular recognition. As proof of concept, an analysis of human leukemia CCRF-CEM cells was performed using aptamer Sgc8c-modified Cu鈥揂u NPs as the colorimetric probe. Results showed that Sgc8c-modified Cu鈥揂u NPs successfully achieved a simple, label-free, cost-effective, visualized, selective, and ultrasensitive detection of cancer cells with a linear range from 50 to 500 cells/mL and a detection limit of 5 cells in 100 渭L of binding buffer. Moreover, feasibility was demonstrated for cancer cell analysis in diluted serum samples. The iodide-responsive Cu鈥揂u NP-based colorimetric strategy might not only afford a new design pattern for developing cancer cell assays but also greatly extend the application of the iodide-catalyzed colorimetric system.