| AVS 62nd International Symposium & Exhibition | |
| Spectroscopic Ellipsometry Focus Topic | Thursday Sessions |
| Session EL+EM+EN-ThM |
| Session: | Spectroscopic Ellipsometry: Novel Applications and Theoretical Approaches |
| Presenter: | Yu Niu, Institute of Mechanics, Chinese Academy of Sciences, China |
| Authors: | Y. Niu, Institute of Mechanics, Chinese Academy of Sciences, China G. Jin, Institute of Mechanics, Chinese Academy of Sciences, China |
| Correspondent: | Click to Email |
Breast cancer which develops from breast tissue is the leading type of cancer in women worldwide, accounting for more than 25% of all carcinogenesis [1]. Compared with other common cancers, the survival rate of breast cancer is remarkably positive and optimistic that between 80% and 90% of those in developed country could be alive for at least 5 years. Therefore, screening high risk population and further concluding a clinical diagnosis in the early stage act as a pivotal factor to cure breast cancer, because it can provide overwhelming contribution to carry out essential therapy in time. Carbohydrate Antigen 15-3 (CA 15-3) and Carbohydrate Antigen 242 (CA 242) are widely-used tumor markers for breast cancer in clinic and their concentrations in serum vary sensitively with breast cancer genesis. The biosensor based on imaging ellipsometry (BIE) for visualization of biomolecular interactions was reported in 1995 [2] and now it is composed of a 48 protein unit array and imaging ellipsometry reader with a field of view (20 x 30 mm) and good resolution for protein adsorption layer on a silicon substrate (lateral and vertical is 1 μm and 0.1 nm, respectively) [3]. In this investigation, joint detection of these two tumor markers simultaneously has been performed with BIE as a trial for screening breast cancer for clinical purpose.
To realize the joint detection, a series of design and optimization has been performed, including the ellipsometric setting, ligand immobilization strategy, ligand surface density, as well as the blocking and rinsing procedures. The test concentration range calibration and the detection limit for quantitative detection have been established by standard samples, which meet the standards of clinical test. By diluting sera to the detection range fitting to the calibration curves, joint quantitative detection of CA 15-3 and CA 242 can be achieved simultaneously.
149 serum samples composed of both the healthy and patients have been performed with BIE. Compared with the results obtained by standard approaches in clinic, the correlation analysis indicates the BIE are highly consistent with clinical methods. In order to estimate the BIE performance for tumor markers detection, ROC curve analysis has been introduced. Its result suggests that the single marker detection by BIE presents good capability to distinguish the normal from patients and the joint detection of CA 15-3 and CA 242 plays a positive role in the improvement of the diagnosis specificity and accuracy.
Reference
[1] A. Jemal, et al., CA Cancer J. Clin.61, 69 (2011).
[2] G. Jin, et al., Anal. Biochem.232, 69 (1995).
[3] G. Jin, et al., Thin Solid Films519, 2750 (2011).