Carbon-nanofiber-based probing arrays for multipoint integration with cellular matrices

Abstract

The self-assembling and controlled synthesis properties of vertically-aligned carbon nanofibers (VACNF) have been exploited to provide parallel subcellular and molecular-scale probes for biological manipulation and monitoring. VACNFs possess many attributes that make them very attractive for implementation as functional, nanoscale features of microfabricated devices. For example, they can be synthesized at precise locations upon a substrate, can be grown many microns long, and feature sharp, nano-dimensioned tips. They also exhibit characteristic electrochemical responses similar to conventionally studied materials such as the edge plane of pyrolytic graphite and surface-activated glassy carbon. This, and their needlelike, vertical orientation upon a substrate, makes them particularly attractive as multielement cellular scale probes or as a parallel embodiment of traditional single-point microinjection or microelectrophysiological systems. We will overview our efforts at fabricating and characterizing several embodiments of VACNF cell probing systems. We will also overview surface modification techniques that exploit the rich surface chemistries of VACNF arrays to allow immobilization of active enzymes and transcriptionally active DNA, which can provide sensitivity to specific biological analytes and application of the nanofiber architecture for controlled biochemical manipulation within the cell. Finally, we will overview our techniques of integrating these probing structures with intact cells and how these structures may be used on a massively parallel basis for measurement and control of the intracellular domain.