Design and development of electrochemical sensors with application in bioanalysis

Sammanfattning: There is a continuous search for reliable, robust, easy to use, portable and cost effective analytical tools with applications in food industry, biomedicine, environmental monitoring and homeland security. The main focus of this thesis is the development of electrochemical (bio)sensors and bioanalysis systems (to be applied in two major fields of interest: food & beverage industry and biomedical research) for monitoring key analytes in complex matrices, such as: meat samples, fermentation broths, and cell culture media. The proposed monitoring methods for calpastatin (a meat tenderness biomarker), successfully applied to meat samples, were based on (i) label free capacitive immunosensors and (ii)amperometric immunoassays. The amperometric immunoassay approach was considered to be used when an electrochemical detection system has been designed, fabricated and applied for calpastatin quantification from bovine skeletal muscle. The obtained values were correlated with Warner Bratzler Shear Force data, a routinely used method for meat tenderness determination. Glucose and ethanol were simultaneously monitored during a fermentation process with miniaturized enzyme based amperometric biosensors connected to a microdialysis probe. Besides food analysis applications, the amperometric immunoassay for calpastatin and additionally for μ-calpain detection is very important in biomedicine, both proteins having an important role in the pathology of several diseases. Electrochemical cellular dynamics monitoring has been achieved in real time by using a microfluidic cell culture system, where the electrodes were integrated at the bottom of the cell culture chambers.