Optical Biosensors and Applications to Drug Discovery and Development in Cancer Research

Optical biosensors are well suited to monitor specific molecular interactions and measure the related binding parameters, which are fundamental for the definition of the mechanism of bio-recognition processes, as well as for their modulation. This analytical technique allows the interactions between analytes and immobilized ligands to be studied without labelling the interacting compounds. Label-free assays are valuable and easy-to-use tools in bio-recognition process monitoring, since they confer higher efficiency, flexibility and lower exposure to experimental artefacts. The sample is observed as close to its native state as possible, thus preventing chemical alteration of the interacting compounds, which could eventually occlude a binding site, interfere with the molecular interaction process and lead to erroneous responses. Nowadays, optical biosensors are applied in several research areas, such as pharmaceutical research, medical diagnostic, environmental monitoring, food safety, and quality control. This chapter reviews the application of optical biosensors to drug discovery and development in cancer research, focusing on target selection and validation, screening of libraries of compounds for their binding to the target, discovery and monitoring of biomarkers. The basic principles of the technique and the experimental set-up for binding assays are discussed, together with the most useful immobiliszation strategies for target biomolecules.