Dielectrophoretic Micropatterning with Microparticle Monolayers Covalently Linked to Glass Surfaces

• Published in: Langmuir Vol. 20; no. 25; pp. 11005 - 11011
• Main Authors: Suzuki, Masato, Yasukawa, Tomoyuki, Mase, Yoshiaki, Oyamatsu, Daisuke, Shiku, Hitoshi, Matsue, Tomokazu
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07.12.2004
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la048111p

Two-dimensional micropatterns of microparticles were fabricated on glass substrates with negative dielectrophoretic force, and the patterned microparticles were covalently bound on the substrate via cross-linking agents. The line and grid patterns of microparticles were prepared using the repulsive force of negative dielectrophoresis (n-DEP). The template interdigitated microband array (IDA) electrodes (width and gap 50 μm) were incorporated into the dielectrophoretic patterning cell with a fluidic channel. The microstructures on the glass substrates with amino or sulfhydryl groups were immobilized with the cross-linking agents disuccinimidyl suberate (DSS) and m-maleimidobenzoyl-N-hydroxy-succinimide ester (MBS). Diaphorase (Dp), a flavoenzyme, was selectively attached on the patterned microparticles using the maleimide groups of MBS. The enzyme activity on the patterned particles was electrochemically characterized with a scanning electrochemical microscope (SECM) in the presence of NADH and ferrocenylmethanol as a redox mediator. The SECM images proved that Dp was selectively immobilized onto the surface of microparticles to maintain its catalytic activity.