Modeling and Optimization of a Continuous-flow Microfluidic Biochip for Food Analysis

Microfluidic systems are increasingly popular for rapid and cheap biochemical analysis in different sectors. In this study Reduced Order Models (ROM) were developed for the optimization of enzymatic assays performed in a microchip. The model enzyme assay used was beta-galactosidase (beta-Gal) that catalyzes the conversion of Resorufin beta-D-galactopyranoside (RBG) to a fluorescent product, resorufin. The assay was implemented in a microfluidic device as a continuous flow system controlled electrokinetically and with a fluorescence detection device. The results from ROM agreed well with both Computational Fluid Dynamic (CFD) simulations and experimental values. While the CFD model allowed for assessment of local transport phenomena, the CPU time was significantly reduced by the ROM approach. The operational parameters of the assay were optimized using the validated ROM to significantly reduce the amount of reagents consumed and the total biochip assay time. After optimization the analysis time was reduced from 20 min to 5.25 min, which also resulted in 50% reduction in reagent consumption. Hence, modeling is an important tool to transform existing and new bioassays in to high performance multiplexed biochips aimed at multi-component analysis systems that have a wide range of applications.