Nanostructured and nanoscale devices, sensors and detectors

In reduced dimensions, materials display characteristics quite different from their bulk behavior. Interestingly, most viruses, bacteria, pathogens, particles in gas phase and other chemical-biological agents, which form the basis of this investigation, also have comparable dimensions. Our present and ongoing investigation is aimed towards the detection of chemical and biological agents using nanostructured materials. We have studied nanotubes, nanoparticles, nanowires, and nanoporous materials for biocompatibility and subsequent detection. In addition, based on our field emission studies on carbon nanotubes, we have suggested device designs to detect environmental emission. Detection strategies and preliminary data from electrochemical sensors, atomic force microscopy, and surface plasmon resonance are presented for the detection of chemical-biological agents immobilized on layers of nanoparticles. As a critical step in the development of sensors/detectors, strategies for surface functionalization and immobilization for carbon nanostructures, nanoparticles, and nanoporous materials are also presented. Such devices display unique characteristics, morphological flexibility, and biocompatibility. The eventual objective of our investigation is to develop a nanotechnology based sensor platform that will enable the direct electrical, optical, or electrooptical detection of biological and chemical agents in a label-free, highly multiplexed format over a broad dynamic range. (c) 2005 Elsevier Ltd. All rights reserved.