(76a) Stimuli-Responsive Microfluidic Valves for Antigen Detection

There is increasing interest in the use of microfluidic devices in the detection and isolation of rare cellular species (circulating tumor cells and multipotent cells).  These microfluidic capture approaches are typically limited to the recognition of a single surface marker on cells, and confirmation of the cellular identity is typically accomplished through immunofluorescence and microscopy.  Here we demonstrate surface-mediated enzymatic polymerization as a simple approach to alter the flow pattern of a microfluidic device in response to the presence of a targeted biomaterial, and enable automated detection against additional biomarkers.  In this novel approach, a flow-blocking polymerization event occurs only in response to the biodetection event of interest.  When the antigen of interest is present, polymerization occurs rapidly, and prevents flow through the microchannel at pressures greater than 15 psig.