Routes to calcifled porous silicon: implications for drug delivery and biosensing

This work describes methods for the fabrication of calcium phosphate films on crystalline silicon substrates, with the long-term goal of employing such materials in either drug delivery or sensing applications. The emphasis of this particular account encompasses both film fabrication as well as surface modification strategies relevant to the sensing of bio-molecular species. For the former, a new process for calcium phosphate film formation is described entailing the use of a high energy DC spark onto silicon surfaces in the presence of Ca-10(PO4)(6)(OH)(2). For sensing purposes, routes to modification of the calcium phosphate/porous silicon surface have been achieved via the use of bifunctional bisphosphonate derivatives, with proof-of-concept demonstrated by the covalent attachment of fluorescent fluorescein tags.