Degradation of functionalized porous silicon in simulated gastric fluid

CHED 459

Hieu Minh Dam, porterl@wabash.edu and Lon A. Porter Jr. Department of Chemistry, Wabash College, Crawfordsville, IN 47933
Owing to its photoluminescent properties and high surface area, porous silicon (por-Si) has shown great potential toward a myriad of applications including optoelectronics, biocomposite materials, and biomedical implants. However, the native hydride- termination is only metastable with respect to surface oxidation under ambient conditions. Efforts in our lab to form stable organic monolayers on porous silicon through direct, covalent silicon-carbon linkages have utilized a variety of facile, yet efficient functionalization methods. Alkyl monolayers of varying chain length were prepared by carbocation, thermal, and Lewis acid mediated hydrosilylation. The functionalized por-Si samples, as well as control and oxidized samples, were immersed in simulated gastric fluids to replicate the conditions of potential por-Si biosensors or medicinal delivery systems in the human body. Degradation of the underlying por-Si surface was monitored using infrared spectroscopy and scanning electron microscopy at various time intervals.