Biomedical/analytical applications of deposited nanostructured Si films

Abstract

We report on various biomedical applications of our deposited nanostructured column–void Si films including respiratory monitoring, quick mass analysis for proteomics, and cell attachment. These applications exploit certain unique attributes of our nanostructured Si material that are not present for bulk Si, such as molecular immobilization, enhanced coupling with electromagnetic radiation, high surface area, and pronounced hydrophobicity. A brief review of morphology and film growth is also given according to our latest understanding. Our capability of controlling columnar separation and porosity by varying film growth conditions allows the tailoring of the properties of our films as well as the optimization of the performance in an application. The fact that these films can be deposited on low processing temperature substrates such as plastics further enhances their versatility.

Nanostructure formation in polymer thin films influenced by humidity

“…Nanostructured surfaces are of increasing interest not only in the field of biological applications, 1 but also for technological purposes as for surface coatings. For industrial applications, it is important that the nanostructured surfaces can be prepared in a cheap and highly reproducible way, which enables the nanostructuring of large areas of substrates.…”

Laser desorption/ionization mass spectrometry on nanostructured semiconductor substrates: DIOS™ and QuickMass™

“…The surface is continuous but has voids parallel to the surface. It was noted that the surface morphology of the QuickMass TM substrates, does not share a similarity with the columnar/voids Si thin-film substrate produced by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) described in [36][37][38]. According to the reference sources [39,40], the QuickMass TM substrate was prepared by physical vapor deposition (PVD) and this deposited thin-film replaced the columnar/voids film developed previously, because the columnar/voids film tended to have a high chemical background in the low mass region of the mass spectra, due to hydrocarbon contaminants adsorption.…”

Surface-assisted laser desorption/ionization mass spectrometry

“…Currently, germanium columnar/void films prepared by this method are commercially available under the name of Quickmass ® from Shimadzu Corp. These films are reportedly stable under ambient conditions for over 1 year without observable loss to its LDI-MS activity, providing an archival capability that is comparable to the functionalized DIOS chips described earlier [46]. Since these films have only recently become available, little work has been reported on their use to date.…”

“…The authors have observed mass spectra of several low-molecular-weight molecules desorbed from mesoporous silica films without added matrix. Fonash and coworkers have hypothesized that silica deposited on planar silicon helps couple the laser light to the silicon surface to promote ionization of deposited analytes [46]. Drug candidates such as fosmidomycin have been subjected to SALDI-MS analysis as a quality control step prior to use in inhibition experiments in Dattelbaum and Iyer's laboratory.…”