Iron Oxide/Gold Core/Shell Nanoparticles for Ultrasensitive Detection of Carbohydrate−Protein Interactions
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- 作者：Chi-Hui Liang ; Cheng-Chi Wang ; Yu-Chen Lin ; Chung-Hsuan Chen ; Chi-Huey Wong ; Chung-Yi Wu
- 刊名：Analytical Chemistry
- 出版年：2009
- 出版时间：September 15, 2009
- 年：2009
- 卷：81
- 期：18
- 页码：7750-7756
- 全文大小：240K
- 年卷期：v.81,no.18(September 15, 2009)
- ISSN：1520-6882
文摘
Changes in the expression of cell surface glycan are often associated with malignant metastasis. The expression level may be dramatically enhanced during tumor progression. A highly sensitive assay that is capable of detecting low levels of cancer-associated carbohydrate antigens can be a powerful tool for early diagnosis. In this work, an ultrasensitive glycans array using iron oxide/gold core/shell nanoparticles conjugated with antibodies or proteins is developed. A magnetic field is applied to quickly bring nanoparticle labeled proteins or antibodies from a solution to an array of carbohydrates immobilized on glass slides and to help them to encounter the carbohydrates at very low concentration. The gold shell provides a well established platform for conjugation of biomolecules. Well-defined recognition systems, namely, mannose derivatives (Man1, Man4, and Man9) with a mannose binding lectin (Concanavalin A) and a stage-specific embryonic antigens-3 (SSEA-3) with a monoclonal antibody (anti-SSEA-3) were chosen to establish this detection tool. Array systems were conducted to determine their surface dissociation constant (KD,surface) and their binding specificity for qualitative and quantitative analysis of carbohydrate−protein and carbohydrate−antibody interactions. When coupled with a signal amplification method based on nanoparticle-promoted reduction of silver, the sensitivity of an iron oxide/gold core/shell nanoparticle-based assay reached to subattomole level in carbohydrate detection.