Overview of Optical Biosensors for Early Cancer Detection: Fundamentals, Applications and Future Perspectives

SIMPLE SUMMARY: Due to the increase in cancer incidence worldwide, a necessity for early cancer detection arises. Since the conventional detection and treatment techniques are costly, great efforts have been exerted in developing new methods for early cancer detection. Highly reliable and efficient methods are based on optical detection techniques, which are sensitive, accurate, rapid, noninvasive and immune to external fields. This includes optical biosensors based on plasmonic waveguides and metamaterial. Additionally, many optical detection methods have been adopted using the colorimetric technique, optical coherence tomography, surface-enhanced Raman spectroscopy and reflectometric interference spectroscopy. This review paper introduces the basic features of each optical detection technique focusing on recent research works toward cancer detection. ABSTRACT: Conventional cancer detection and treatment methodologies are based on surgical, chemical and radiational processes, which are expensive, time consuming and painful. Therefore, great interest has been directed toward developing sensitive, inexpensive and rapid techniques for early cancer detection. Optical biosensors have advantages in terms of high sensitivity and being label free with a compact size. In this review paper, the state of the art of optical biosensors for early cancer detection is presented in detail. The basic idea, sensitivity analysis, advantages and limitations of the optical biosensors are discussed. This includes optical biosensors based on plasmonic waveguides, photonic crystal fibers, slot waveguides and metamaterials. Further, the traditional optical methods, such as the colorimetric technique, optical coherence tomography, surface-enhanced Raman spectroscopy and reflectometric interference spectroscopy, are addressed.