TNT displacement immunoassay with integrated microfluidic micromixer components

A displacement immunosensor for the detection of 2,4,6-trinitrotoluene (TNT) using inline integrated microfluidic mixer grooves is demonstrated. The key components of the microfluidic mixer are chevrons and stripes, layered in opposite directions on the top and bottom of the microchannel, to create a turbulent mixing of biomolecules as they migrate through the channel. This mixing phenomenon generates advection patterns that provide increased antibody-antigen interaction resulting in enhanced immunoassay sensitivity. Displacement immunoassays for TNT demonstrated femto-mole detection levels (50 nanograms/liter). Combining sol-gel based chemistry, a microchannel-based immunosensor milled in polymethyl methacrylate (PMMA) and the unique features of a grooved surface offers the potential for a field-portable, ruggedized sensor.