Carbon nanofibrous mat (nano-felt) surface-attached with Pd nanoparticles was prepared from electrospun polyacrylonitrile nano-felt surface-functionalized with amidoxime groups, and its application for hydrogen sensing was explored. The material consisted of relatively uniform and randomly overlaid carbon nanofibers with diameters of similar to 300 nm, while the attached Pd nanoparticles had sizes in the range from a few to tens of nanometers. The electrospun carbon nano-felt was mechanically flexible/resilient, and the resistance of the material varied upon exposure to H-2 at room temperature. The study suggested that electrospun carbon nano-felts surface-attached with metal nanoparticles could be a material of choice for the fabrication of gas- and/or bio-sensors, and the amidoxime-functionalization of electrospun polyacrylonitrile nano-felt could be a general approach for the development of various carbon nano-felts surface-attached with different metal nanoparticles. (c) 2011 Elsevier B.V. All rights reserved.