Fabrication and chemical surface modification of mesoporous silicon for biomedical applications

Self-Adjusting Electrochemical Etching Technique for Producing Nanoporous Silicon Membrane

“…Electrochemical etching was performed to form pores on the silicon membrane surface using hydrofluoric acid (HF) solution [21,39,46,48]. The experimental setup was shown in Figure 15 by supplying a constant current between two electrodes immersed in a Teflon cell containing an aqueous solution of HF or diluted HF.…”

“…An ethanol and HF solution is commonly used among researchers as an electrolyte aqueous solution for electrochemical etch. Ethanol will act as the surfactant in reducing the hydrogen bubble throughout the process [46,48]. Fluorescence light is put facing the silicon membrane during electrochemical etching process as a catalyst in producing a well-forming pore during pore formation mechanism [15,17].…”

Silicon Direct Opals

“…A recent application for p-Si is drug delivery, where drug molecules or proteins are loaded into the porous matrix and released into the body as the matrix degrades. [4,5] Since the discovery of luminescence from p-Si, research has focused on improving the room-temperature emission efficiency from this and other related silicon structures, and on understanding the mechanisms that give rise to such emission. Highly porous Si contains quantum-size crystalline structures responsible for the visible emission.…”

Porous Silicon-based Electrochemical Biosensors

“…Nevertheless, many other applications have since been the object of much research, thanks to the many advantages of porous silicon: the flexibility of its formation process (Föll et al 2002), the extensive tailoring of its structural properties (Lehmann et al 2000), the very large specific surface (Halimaoui 1993) and also its biocompatibility, mandatory for both drug delivery devices and several biosensing applications (Low et al 2009;Park et al 2009). The deep knowledge of silicon chemistry is easily applicable to porous silicon (Buriak 2002;Salonen and Lehto 2008) and allows functionalization of the internal pore surface for the chemical bonding of the biological molecules of interest or for a better stabilization of the structure. The relevance for the field of PSi biosensors of a well controlled surface chemistry has been detailed by Lees and coworkers and by Kilian and coworkers (Lees et al 2003;Kilian et al 2009) and will be treated more deeply later in this article.…”