Preparation of gas sensors via dip-pen nanolithography

In the present work, a conducting polymer, doped polypyrrole, was used to develop a gas sensor by dip-pen nanolithography (DPN). The response time of the sensor to 18 ppm CO2 was 9 s. The sensor response increased linearly as the CO2 concentration increased. A possible mechanism for the CO2 sensing was discussed. (C) 2007 Elsevier B.V. All rights reserved.