Electrospun zinc oxide nanofibers for UV sensing with quartz crystal microbalance technique

An ultraviolet (UV) sensor consisting of a zinc oxide (ZnO) nanofiber sensing membrane and a quartz crystal microbalance (QCM) was fabricated. ZnO nanofibers were prepared by electrospinning and calcination. The morphology and structure of the nanofiber sensing membrane were characterized by scanning electron microscopy and X-ray diffraction. The QCM sensor based on ZnO nanofibers was found to be sensitive to 254-nm UV light in nitrogen, oxygen and air atmospheres. When the QCM sensor was placed under UV irradiation, the resonant frequency difference rapidly decreased. When the light was removed, the frequency difference recovered until reaching 0 Hz. The stability and repeatability of the proposed ZnO nanofiber-based QCM sensor were demonstrated, and the sensing mechanism was briefly discussed.