Highly Stable Porous Silicon鈥揅arbon Composites as Label-Free Optical Biosensors
详细信息 查看全文
- 作者：Chun Kwan Tsang ; Timothy L. Kelly ; Michael J. Sailor ; Yang Yang Li
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：December 21, 2012
- 年：2012
- 卷：6
- 期：12
- 页码：10546-10554
- 全文大小：511K
- 年卷期：v.6,no.12(December 21, 2012)
- ISSN：1936-086X
文摘
A stable, label-free optical biosensor based on a porous silicon鈥揷arbon (pSi鈥揅) composite is demonstrated. The material is prepared by electrochemical anodization of crystalline Si in an HF-containing electrolyte to generate a porous Si template, followed by infiltration of poly(furfuryl) alcohol (PFA) and subsequent carbonization to generate the pSi鈥揅 composite as an optically smooth thin film. The pSi鈥揅 sensor is significantly more stable toward aqueous buffer solutions (pH 7.4 or 12) compared to thermally oxidized (in air, 800 掳C), hydrosilylated (with undecylenic acid), or hydrocarbonized (with acetylene, 700 掳C) porous Si samples prepared and tested under similar conditions. Aqueous stability of the pSi鈥揅 sensor is comparable to related optical biosensors based on porous TiO2 or porous Al2O3. Label-free optical interferometric biosensing with the pSi鈥揅 composite is demonstrated by detection of rabbit IgG on a protein-A-modified chip and confirmed with control experiments using chicken IgG (which shows no affinity for protein A). The pSi鈥揅 sensor binds significantly more of the protein A capture probe than porous TiO2 or porous Al2O3, and the sensitivity of the protein-A-modified pSi鈥揅 sensor to rabbit IgG is found to be 2脳 greater than label-free optical biosensors constructed from these other two materials.