The authors present a biosensor using pyrolyzed electron beam resist nanostructures as an active conducting channel. Versatile, arbitrarily shaped nanostructures such as nanowires, nanodots, and suspended nanobridges are fabricated by a facile electron beam resist thermal decomposition method. The nanostructures typically show 15-21 nm thickness, 100-200 nm width, 0.6 nm roughness, and p-type majority conduction with tailored resistivity of 5.2-0.75 Omega cm. Streptavidin-biotin binding and pH dependent conductance modulation are demonstrated using pyrolyzed resist based devices. (c) 2007 American Institute of Physics.