Label-free detection of biomolecular interaction by optical sensors

Since the first label-free optical biosensor was commercialized in 1990 a r ising number of publications have demonstrated the benefits of direct biomo lecular interaction analysis (BLA) for biology and biochemistry. This artic le first gives an overview of the historical development of different trans ducer principles used for the detection of BIA. Subsequently, the four majo r parts of a biosensor system: transducer, sample handling, surface/immobil ization chemistry and test formats/data evaluation will be discussed, with a main focus on the test formats and data evaluation. The intention of this review is to present an introduction to the field and to point out the dif ficulties most frequently encountered.