Research into nanoporous gold has accelerated over the last 20 years, with the material showing promises in biosciences, sensing and catalysis applications, and energy storage applications.1,2, Accurate characterization of nanoporous gold is, of course, crucial for the continued development of these technologies. Research from Fraunhofer IFAM shows how dual-beam Focused Ion Beam and Scanning Electron Microscopy (FIB-SEM) imaging techniques can be combined with advanced image-processing, physical modeling, and Pore Network Modeling (PNM) to produce detailed quantitative analyses of nanoporous gold samples.
Nanoporous Gold contains pores with diameters of the order of tens of nanometers, which precise size can easily be tuned during fabrication. The resulting biocompatible, physically stable and nanotextured surface have made it especially attractive for applications in biosensing, drug release and selective catalysis.3–5 Other properties of interest include high electrical conductivity and plasmonic properties. 6,7
The surface of nanoporous gold is readily modified using self-assembled monolayer (SAM) technology or can readily adsorb certain molecules directly. Tuning the pores to the same order of size as proteins, oligonucleotides, antibodies, and enzymes can facilitate the incorporation of such biomolecules within the structure to produce biosensors. Similarly, tuning the pore size to the order of specific chemical reactants has been shown to produce reusable and highly specific catalysts. The same porous structure and high surface area had led to nanoporous gold also being investigated for potential applications in fuel cells and supercapacitors.8,9