Protein analysis in polymer based microfludic chips for diagnostic purposes

Enzymes are mainly globular proteins, having significant roles in the biological systems of all living organisms. The high concentration or absence of proteins in blood can further be used in diagnosis of a particular pathology at an early stage. Current studies are intensely based on the analysis of interaction and detection of proteins. Lab-on-a-chip (LOC) systems with high sensitivity and limited reagent consumption allow miniaturized and parallelized reactions simultaneously. In comparison to the conventional platforms, higher reaction yields and rates, rapid heat exchange as well as mass transfer can be obtained in microfluidic systems due to their micro-dimensions. As a result of these advantages, the use of LOC is increasing in the field of biocatalysis by using both free and immobilized enzymes. Incorporation of multiple enzymes on a microfluidic platform instead of a single enzyme is getting more important for diagnosis of a diseases. Thus, the aim of this study was to adapt liver enzymes to the LOC systems to enhance more practical and affordable enzyme tests. Therefore, polymer, glass and paper based microplatforms were designed, developed, and compared to find out the best platform to detect enzyme levels in body fluid samples. Spectroscopic analysis, electrical measurement and qualitative color analysis were used as detection methods. The most significant results were obtained through the spectroscopic analysis. The latter method was qualitative color detection and it was observed that with the descending concentration of enzyme, the color shade was changing as well. In regards to the electrical sensing model, it is concluded that the designed electrode system which requires more complex structure and optimization parameters, was not applicable for this study.