A REVIEW ON THE APPLICATION OF THE OPTICAL BIOSENSORS

Abstract

A significant number of identification concepts have been reported over the last decades in the sector of bio- and chemosensors. These concepts of detection are focused either on the observation of fluorescence-labelled structures or on the heterogeneous process of direct optical detection. Direct optical detection may be determined by remission, by micro-refractivity measurement or interference measurement. Either Mach-Zehnder interferometers or calculation of changes in the layer's physical thickness caused, for example, by swelling effects in polymers or in bioassays, often play a significant role in the last instance. An summary of the methods of microrefractometric and microreflectometric concepts is presented here, and the advantages and disadvantages of the different techniques are seen using samples from the field of chemo and biosensors. Sensor efficiency depends not only on the concepts of transduction, but on the complete sensor device identified by this transduction, the responsive substrate, the electronics for data acquisition, and the software for assessment. Therefore, the aim of this article is to illustrate the essential of the relationship of these components within the device, and the focus is on optical sensing using planar transducers. The shortage of chemosensor selectivity could either be balanced through the use of sensing devices or by analysing time-resolved analyte/sensitive layer interaction measurements. Chemometrics requires the quantification of mixtures of analytes in all situations. Even using cross-reactive antibodies, these data-processing approaches have also been applied successfully to antibody/antigen interactions. Due to the fact that miniaturisation and parallelisation have become important approaches in recent times, certain issues and current developments will be addressed, particularly for bio-applications.