Time Optimization of Heterogeneous Immunoassay Using PDMS Microfluidic Chip for Quantitative Detection of a Model Analyte

Heterogeneous immunoassay (HI) has been recently used for on-chip biomolecule detection by many researchers due to its high specificity and precision. However, the protocols that have been published are too time-consuming. For HI based immunosensor to be attractive they should have short analysis times. In our work, a polydimethylsiloxane (PDMS) microfluidic device was fabricated to quantify a model analyte (bovine IgG) and used for optimizing the time required for each process. The results show that the incubation time of one single process could be reduced from typical 1 hour to 5 minutes without loss of performance. Our studies reveal that microfluidic devices are only effective in reducing incubation times for diffusion limited processes but not for interaction or adsorption limited process.