The application of surface plasmon resonance (SPR) immuno-biosensors for medical diagnosis ; Anwendungen von Oberflächenplasmonresonanz-Immunobiosensoren für medizinische Diagnosen

A biosensor is an analytical device to detect target analyte in a complex mixture by using high selectivity of biomolecules as the molecular recognition tool. Especially, the immunoaffinity (IA) biosensor exploits the highly specific and selective interaction between antigen and antibody for the detection of a target analyte. The surface plasmon resonance (SPR) sensor was used for label-free detection and real-time monitoring, and SpreetaTM was used for this work. The major objective of this work is the development of SPR biosensor for medical diagnosis with the features of a cost-effective test by 'additive assay';, short analysis time through 'simultaneous detection'; and high sensitivity by 'signal amplification';. [1] First topic is a reuse method of IA biosensor called 'additive assay';. In the 'addtive assay'; method, the sample is repeatedly injected to the IA layer without removing the already bound analytes by chemical treatment and then the concentration of sample is calculated from the actually measured signal by using previously prepared correlation curve between the accumulated concentration of additively injected sample and accumulated signal which represents the number of occupied binding sites. The application of additive assay for real medical diagnosis was demonstrated by using tumor marker (CA 19-9) as a target analyte. When the concentrations of four samples were analyzed by using the correlation curve of CA 19-9, the average deviation of the calculated concentrations from the real concentrations was estimated to be 5.3 %. [2] The second topic is the 'simultaneous detection'; which enables the detection of multiple analytes on the single sensor element with single sample treatment. In the 'simultaneous detection';, a sample with several analytes is treated to the single sensing region which has multiple receptors for each target analyte and then the concentrations of each analyte is analyzed sequentially by using the respective correlation between the concentration and signal. In this work, ...