Microfluidic devices hold great promises as the tool that could enable low-cost, point-of-care diagnostic procedures. In order to create a true lab-of-a-chip device, microfluidic chips have to be able to handle multi-step biological detections that are common in many diagnostic procedures. Dynamic bead-based microarrays enable the detection of inflammatory cytokine, interferon-gamma (IFN-γ), via a six-step apatmer-based assay with five additional wash steps. In this novel microfluidic chip, the specially designed micropost array allows researchers to trap and release the microbeads by controlling the direction of flow in the chip. By washing undesirable solution-phase binding reagents associated with decreased assay sensitivity and increased background noise, we were able to achieve sensitivity down to 100pM.
Sochol, R., Lo, L., Ruelos, R., Chang, V., Bahri, D., Iwai, K., Lo, J., Dueck, M., Song, L., Lee, L., Lin, L., Microfluidic Ping Pong for Cytokine Detection, Proceedings of 24th IEEE Micro Electro Mechanical Systems Conference (MEMS 2011), Cancun, Mexico