A smart bioscaffold of nanowires for monitoring proteins

by Chen, Feng; Dong, Wenjun; Zhang, Tierui Z.; Ali, Syed F.; Duhart, Helen M.; Tian, Z. Ryan

Monitoring important proteins in bioscaffold's micron-scale pores, like growth hormones that are crucial in tissue regenerations, is challenging and was seldom reported before. In simple electrochem. sensing of proteins in polypeptide- and/or polymer-based bioscaffolds that often have a poor elec. cond., a fast electron transfer across the bioscaffold may be difficult. We hereby report a smart bioscaffold of titanate (or TiO2-based) NWs that can support the growth of neural cells (e.g. pheochromocytoma cells, or PC-12) and can detect 45 pmol of the redox-active heme protein such as cytochrome c, or cyt c. The NWs are easy and inexpensive to fabricate, and chem. and thermally stable, with no denaturation of the redox proteins on the NWs or in the Bioscaffolds. The hydroxyl (-OH) groups on the NW surface at pH 6.2-9 may act as "wet-electrons" to form a low-energy path for a fast ET on the NW surface, and the formal potential of the cyt c was found to be pH independent in this system. Currently ongoing work on surface functionalization and NW surface property optimization may enable us to develop a family of new multiplexed chem. and biochem. sensors in a variety of applications inclduing stem cell growth, proteomics, cell recognizing/arresting, etc.