Approach to Quantitative Detection of CD146 with a Label-free Protein Biosensor Based on Imaging Ellipsometry

Abstract

CD146 glycoprotein belonging to cell adhesion molecules is considered to be a novel target on endothelial cell involved in tumor angiogenesis. The biosensor based on imaging ellipsometry (BIE) which is performed in null and off-null mode is used for CD146 detection as a trial by the following steps. Firstly, anti-CD146 antibody as ligand is immobilized on Protein G modified silicon substrate. Then, CD146 test is carried out and its calibration curve is established for the requirement of quantitative detection. Finally, 18 serum samples are detected quantitatively and their results are validated by ELISA's. The sensitivity for CD146 detection achieves the order of ng/ml and the relationship between BIE signal y (grayscale value) and CD146 concentration x (ng/ml) is y=3.3ln(x) +91.3. Compared with ELISA's, the majority of results are in agreement, and the results of two approaches have significant statistic relevance.