Nanoconstriction-based electrodeless dielectrophoresis chip for nanoparticle and protein preconcentration

Abstract

An electrodeless dielectrophoresis (EDEP) microchip is proposed for the concentration of nanoscale particles and proteins in a 150 nm nanoconstriction gap in a microchannel. Notably, the nanoconstriction is fabricated using a simple thermal-oxidation shrinkage process. It is shown that the nanoconstriction enhances the local electric field intensity by a factor of 1 × 103. The strong electric field and field gradient result in concentration enrichment by factors 1 × 104 and 1 × 103 for nanoparticles and proteins, respectively, within 30 s. Thus, the proposed EDEP chip has significant potential for achieving rapid and highly sensitive protein detection and for biomarker discovery applications.