A portable sensor device incorporates a low-power, nanostructure sensor coupled to a wireless transmitter. The sensor uses a nanostructure conducting channel, such as a nanotube network, that is functionalized to respond to a selected analyte. A measurement circuit connected to the sensor determines a change in the electrical characteristic of the sensor, from which information concerning the present or absence of the analyte may be determined. The portable sensor device may include a portable power source, such as a battery. It may further include a transmitter for wirelessly transmitting data to a base station.