Synthesis of sol-gel encapsulated heme proteins with chemical sensing properties

Abstract
Heme proteins such as cytochrome-c (cyt-c), hemoglobin (Hb), and myoglobin (Mb) have been successfully encapsulated in sol-gel derived silica matrices, retaining their spectroscopic properties and chemical function. The thermal stability of cyt-c was significantly improved by immobilization in a porous silica network. Results from optical absorption, resonance Raman, and thermal denaturation studies suggest that biomolecules such as cyt-c design self-specific pores in the silica network according to the size and shape requirements of the biomolecule. Hb and Mb, immobilized using the sol-gel process, bound ligands similar to the proteins in aqueous buffer, and silica-encapsulated manganese myoglobin (MnMb) was a viable detector for nitric oxide (NO).