An integrated sensor system was developed using mats formed of electrospun polymer/single-walled carbon nanotube composite nanofibers combined with inter-digitated electrodes directly printed on the surface to detect volatile organic compounds. When the polymer in the fibers swells due to vapor adsorption, the carbon nanotubes separate from each other and increase electrical resistance of the material. The conductivity change of the composite-sensing material was monitored with a multi-meter when exposed to volatile organic compounds. The response to different vapors showed a linear relationship between resistance change and vapor concentration. We obtained both sensitivity and selectivity data on the sensor with several different vapor analytes - methanol is used as an example in this paper. (C) 2013 Elsevier B.V. All rights reserved.