title: Microfabrication of nanoporous gold patterns for cell-material interaction studies.
abstract: Nanostructured materials with feature sizes in tens of nanometers have enhanced the performance of several technologies, including fuel cells, biosensors, biomedical device coatings, and drug delivery tools. Nanoporous gold (np-Au), produced by a nano-scale self-assembly process, is a relatively new material that exhibits large effective surface area, high electrical conductivity, and catalytic activity. These properties have made np-Au an attractive material to scientific community. Most studies on np-Au employ macro-scale specimens and focus on fundamental science of the material and its catalytic and sensor applications. The macro-scale specimens limit np-Au's potential in miniaturized systems, including biomedical devices. In order to address these issues, we initially describe two different methods to micropattern np-Au thin films on rigid substrates. The first method employs manually-produced stencil masks for creating millimeter-scale np-Au patterns, while the second method uses lift-off photolithography to pattern sub-millimeter-scale patterns. As the np-Au thin films are obtained by sputter-deposition process, they are compatible with conventional microfabrication techniques, thereby amenable to facile integration into microsystems. These systems include electrically-addressable biosensor platforms that benefit from high effective surface area, electrical conductivity, and gold-thiol-based surface bioconjugation. We describe cell culture, immunostaining, and image processing techniques to quantify np-Au's interaction with mammalian cells, which is an important performance parameter for some biosensors. We expect that the techniques illustrated here will assist the integration of np-Au in platforms at various length-scales and in numerous applications, including biosensors, energy storage systems, and catalysts.
authors.affiliation: Department of Electrical and Computer Engineering, University of California, Davis, USA.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Daggumati
authors.forename: Ozge
authors.initials: O
authors.lastname: Kurtulus
authors.forename: Christopher Abbott Reece
authors.initials: CA
authors.lastname: Chapman
authors.forename: Damla
authors.initials: D
authors.lastname: Dimlioglu
authors.forename: Erkin
authors.initials: E
authors.lastname: Seker
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D008855:Microscopy, Electron, Scanning / Q000295:instrumentation / Q000379:methods; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods; D055616:Microtechnology / Q000295:instrumentation / Q000379:methods*; D041681:NIH 3T3 Cells; D058608:Nanopores; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*
chemical_list: D006046:Gold
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