State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , Nanjing 210023, P.R. China.
School of Chemistry and Chemical Engineering, Shanxi University , Taiyuan 030006, P.R. China.
Anal Chem. 2016 Aug 16;88(16):8339-45. doi: 10.1021/acs.analchem.6b02740. Epub 2016 Aug 5.
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.
这项工作通过在 ITO/TiO2/CdS 电极的光电化学响应上敏化 CdTe 量子点 (QD)，提出了第一种光电化学邻近分析 (PECPA) 方法，用于高度选择性和灵敏地检测蛋白质。该检测是在通过与固定在 ITO/TiO2/CdS 电极上的捕获 DNA 杂交形成的传感界面上进行的，该界面标记有抗体-DNA (DNA-Ab1)。在 Ab1 识别靶蛋白后，形成了 DNA-Ab1、靶标和检测抗体-DNA (DNA-Ab2) 的免疫复合物，这导致 DNA-Ab2、捕获 DNA 和信号 DNA-CdTe QD 中的 DNA 近邻杂交，并将 CdTe QD 带到 ITO/TiO2/CdS 电极产生敏化光电流。光电流强度随特定靶蛋白浓度的增加而增加。使用胰岛素作为靶标，这种敏化方法显示出 10 fM 至 10 nM 的检测范围和 3.0 fM 的检测限，无需洗涤步骤。它对生物基质中的蛋白质具有高选择性和良好的准确性。这种方法非常灵活，可以扩展到各种蛋白质靶标。
