Enhanced Photoelectrochemical Proximity Assay for Highly Selective Protein Detection in Biological Matrixes
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- 作者：Guangming Wen ; Huangxian Ju
- 刊名：Analytical Chemistry
- 出版年：2016
- 出版时间：August 16, 2016
- 年：2016
- 卷：88
- 期：16
- 页码：8339-8345
- 全文大小：406K
- 年卷期：0
- ISSN：1520-6882
文摘
This work proposes the first photoelectrochemical proximity assay (PECPA) method via the sensitization of CdTe quantum dots (QDs) on photoelectrochemical response of ITO/TiO2/CdS electrode for highly selective and sensitive detection of proteins. This detection was performed on a sensing interface formed via the hybridization of capture DNA immobilized on ITO/TiO2/CdS electrode with labeled antibody-DNA (DNA-Ab1). Upon the recognition of Ab1 to target protein, the immunocomplex of DNA-Ab1, target, and the detection antibody-DNA (DNA-Ab2) was formed, which led to the proximity hybridization of the DNA in DNA-Ab2, capture DNA, and signal DNA-CdTe QDs, and brought CdTe QDs to the ITO/TiO2/CdS electrode to produce a sensitized photocurrent. The photocurrent intensity increased with the increasing concentration of the specific target protein. Using insulin as a target, this sensitized method showed a detectable range of 10 fM to 10 nM and a detection limit of 3.0 fM without the need of a washing step. It possessed high selectivity and good accuracy for detection of proteins in biological matrixes. This method is extremely flexible and can be extended to varieties of protein targets.