Microfluidic calorimetric immunosensor: experimental results and COMSOL simulations of heat transfer in microchannel

Recent years have witnessed significant progress in the development of detection technologies for lab-on-a-chip immunoassays that provide increased sensitivity and specificity. The calorimetric technique allows the detection of reactions that are not compatible with other methods. Optimization of thermal transport through the microchannel relates to increasing sensitivity and high-throughput of sample analysis. This study presents the design and fabrication of calorimetric immunosensor for quantification of TNF-α. The impact of channel height (100μm, 500μm, 1000μm), lower channel wall thickness (170μm, 500μm, 1000μm), and MEMS materials (PDMS, glass) were simulated using COMSOL Multiphysics® to investigate the effect of these parameters on the heat transfer within the microchannel. Computational analysis indicates that reducing the channel height and the thickness of the lower channel wall results in an increased temperature difference. The simulations results were validated experimentally in a microfluidic immunosensor with an integrated antimony/ bismuth thermopile for quantification of TNF-α. The accuracy of the developed technology was validated using conventional ELISA.