Ellipsometric biosensors

Abstract

Ellipsometry is an optical technique for the characterization of thin films, generally used in optic/physics researches. In principle, measurement is performed by intensity measurement of polarized light reflecting off a sample surface. Since the linearly polarized light is often converted into elliptically polarized light after reflecting from the sample surface, this technique is called ellipsometry. On the other hand, after its unique advantages have been combined with the technological development in electronics and computing, using ellipsometry as a sensor is in focus in the last 3decades. Nowadays, various ellipsometric techniques have been developed and reported as biomedical tools, particularly in sensor applications. As a sensitive tool, optical property changes of the sensor surface due to biomolecular interactions can be used in sub-nanomolar analyte detection. In this chapter, principles and history of ellipsometry, some milestones in the development of ellipsometric techniques, the place of ellipsometric techniques in biological research, benchmarking against other optical methods, and finally, future expectations in ellipsometry-based research are discussed. In addition, some review articles published with ellipsometry content since 2010 have been listed and summarized for the readers to access more detailed information. © 2023 Elsevier Ltd. All rights reserved.