Solid and hollow ZnO nanofibers were fabricated through a facile single capillary electrospinning. The samples have been characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). A comparative acetone sensing study between the two samples were also performed. The results indicate that the ZnO hollow nanofibers show improved response to acetone at 220 degrees C with good selectivity and stability, which is attributed to the 1D hollow nanostructure. Especially, the sensor can detect acetone down to 1 ppm with obvious response (7.1). The formation mechanism and acetone sensing mechanism of the ZnO hollow nanofibers were also discussed. (C) 2011 Elsevier B.V. All rights reserved.