Low-power, fast, selective nanoparticle-based hydrogen sulfide gas sensor

We demonstrate a small, low-cost, low-power, highly sensitive, and selective nanomaterials-based gas sensor. A network of tungsten oxide nanoparticles is heated by an on-chip microhotplate while the conductance of the network is monitored. The device can be heated with short pulses, thereby drastically lowering the power consumption, without diminishing the sensor response. The sensor shows high sensitivity to hydrogen sulfide and does not have significant cross sensitivities to hydrogen, water, or methane, gases likely to be present in operation. A sensing mechanism is proposed, and its effect on electronic properties is discussed. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3703761]