A Microbead Sieve And Polarographic Detection Cell For Immunoassays With A Modular Microfluidic Interconnect

A microfabricated detector module has been developed for performing sandwich immunoassays on 100 muL samples, Probe antibodies are attached to 40 mum diameter porous microbeads which are entrained inside the detection cell by micromachined silicon membrane sieves. The immunoassay is electrochemically signaled by the change in dissolved O-2 which is detected by means of an integrated polarographic electrode. The detection cell design incorporates a modular microfluidic interconnect technology which uses a micromolded PDMS gasket and micromachined bosses on the backside of the device for mating and sealing onto a microfluidic motherboard.