Electric manipulation of bioparticles and macromolecules on microfabricated electrodes

Bioparticle separation, bioparticle enrichment, and electric field-mediated immune detection were carried out on microfabricated semiconductor chips u tilizing ac and dc electric fields. Microscale separation on a chip surface having an active area of similar to 16 mm(2) was demonstrated for a mixtur e of Bacillus globigii spores and Escherichia coli bacteria. Dielectrophore tic enrichment was performed by collecting target bioparticles from a now s tream in now cells of similar to7.5 muL, achieving a 20-fold increase in th e concentration of E. coli bacteria from a diluted sample, a 28-fold enrich ment for peripheral blood mononuclear cells from red blood cells, and a 30- fold increase in white blood cells from diluted whole blood. The ability to manipulate and collect bioparticles and macromolecules at microfabricated electrodes with ac and dc fields was further illustrated in electric held-m ediated immunoassays for analyzing the biological identities of E, coli bac teria and B. globigii spores. According to these results, the electric meth ods for manipulating bioparticles present themselves as viable techniques f or novel biomedical applications in sample preparations and biochemical ass ays on microelectrode arrays.