Stability of functionalized porous silicon in a simulated gastrointestinal track

CHED 483

Daniel S. Albrecht, porterl@wabash.edu, Hieu Minh Dam, porterl@wabash.edu, Jason L. Siegel, porterl@wabash.edu, and Lon A. Porter Jr. Department of Chemistry, Wabash College, Crawfordsville, IN 47933
Due to its easily tailored surface morphology and high surface area, porous silicon (por-Si) has shown great potential toward a myriad of applications including microscale sensors and biomedical implants. Unfortunately, its native hydride- termination quickly degrades under ambient and aqueous environments. Literature methods report a variety of methods that allow for the preparation of stable organic monolayers on porous silicon through direct, covalent silicon-carbon linkages. Organic monolayers of varying chain length were prepared by microwave, carbocation, thermal, and Lewis acid mediated hydrosilylation. The functionalized por-Si samples, as well as control and oxidized samples, were immersed in simulated gastric fluid and transferred to simulated intestinal fluid to replicate the conditions of potential por-Si biosensors or medicinal delivery systems in the human gastrointestinal track. Degradation of the underlying por-Si surface was monitored using infrared spectroscopy at various time intervals.