Molecular release from patterned nanoporous gold thin films.
Nanostructured materials have shown significant potential for biomedical applications that require high loading capacity and controlled release of drugs. Nanoporous gold (np-Au), produced by an alloy corrosion process, is a promising novel material that benefits from compatibility with microfabrication, tunable pore morphology, electrical conductivity, well-established gold-thiol conjugate chemistry, and biocompatibility. While np-Au's non-biological applications are abundant, its performance in the biomedical field is nascent. In this work, we employ a combination of techniques including nanoporous thin film synthesis, quantitative electron microscopy, fluorospectrometry, and electrochemical surface characterization to study loading capacity and molecular release kinetics as a function of film properties and discuss underlying mechanisms. The sub-micron-thick sputter-coated nanoporous gold films provide small-molecule loading capacities up to 1.12 μg cm(-2) and molecular release half-lives between 3.6 hours to 12.8 hours. A systematic set of studies reveals that effective surface area of the np-Au thin films on glass substrates plays the largest role in determining loading capacity. The release kinetics on the other hand depends on a complex interplay of micro- and nano-scale morphological features.
Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616, USA.
Ozge
O
Kurtulus
Pallavi
P
Daggumati
Erkin
E
Seker
D004058:Diffusion; D019793:Fluorescein / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure*; D058608:Nanopores / Q000648:ultrastructure*; D010316:Particle Size; D016062:Porosity
D053769:Nanocapsules; D006046:Gold; D019793:Fluorescein