Single crystal InN nanorods were successfully grown on c-Al2O3 by hydride-metalorganic vapor phase epitaxy. The measured resistance of bare InN nanorods does not change upon exposure to hydrogen ambient. The addition of sputter-deposited clusters of Pt onto the surface of the InN nanorods, however, produced a significant change in the measured room temperature resistance. The measured resistance changed systematically by 0.5%-12% as the ambient hydrogen concentration in N-2 was varied between 10 and 250 ppm after 15 min exposure time. Importantly, a relatively low power consumption of similar to 0.3 mW was measured under these conditions. There was no response at room temperature to O-2, N2O, or NH3 exposures. (c) 2005 American Vacuum Society.