Porous silicon surface modification functionalization

The radical-based functionalization of silicon surfaces is a growing area because of the potential practical applications. Although further knowledge is needed, the scope, limitations, and mechanism of these reachons are sufficiently well understood that they can be used predictably and reliably in the modification of hydrogen-terminated silicon surfaces. The radical chemistry of (TMSlsSiH has frequently served as a model in reactions of both hydrogen-terminated porous and flat silicon surfaces. We trust that the survey presented here will serve as a platform to expand silicon radical chemistry with new and exciting discoveries. 

Meso-PSi nanoparticles have been used for the delivery of porphyrin drugs (see chapter Drug Delivery with Porous Silicon ) into breast cancer cells in vitro. The porphyrin was covalently immobilized onto the surface of PSi via a new chemical modification scheme, which retains the porphyrin photoactivity. The functionalized nanoparticles were better internalized by cancer cells compared to the plain photosensitizer, and a more efficient cell death was observed (Secret etal. 2013). 

In this chapter we describe the basic principles involved in the controlled production and modification of two-dimensional protein crystals. These are synthesized in nature as the outermost cell surface layer (S-layer) of prokaryotic organisms and have been successfully applied as basic building blocks in a biomolecular construction kit. Most importantly, the constituent subunits of the S-layer lattices have the capability to recrystallize into iso-porous closed monolayers in suspension, at liquid-surface interfaces, on lipid films, on liposomes, and on solid supports (e.g., silicon wafers, metals, and polymers). The self-assembled monomolecular lattices have been utilized for the immobilization of functional biomolecules in an ordered fashion and for their controlled confinement in defined areas of nanometer dimension. Thus, S-layers fulfill key requirements for the development of new supramolecular materials and enable the design of a broad spectrum of nanoscale devices, as required in molecular nanotechnology, nanobiotechnology, and biomimetics [1-3]. 

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