Recently, many researchers are focusing on IoT and wearable computing devices because of their strong potential and extensive applications for a revolutionary effect on future human life. Nanostructured ZnO materials have received attention in a wide range of fields due to their interesting properties. In this work, we deposited Cu electrode on PET mono-filament by RF magnetron sputtering and hydrothermally grown ZnO on between the Cu electrode to fabricate UV sensor for application in IoT and wearable computing devices. We first fabricated ZnO UV sensor on PET mono-filament. We have investigated ZnO UV sensor property by I-V and I-t measurement according to UV power 195µW/cm2, 360µW/cm2, 580µW/cm2, 770µW/cm2 and 1080µW/cm2. We obtained data show ZnO UV sensor has excellent linearity of UV power and resistance. Also, we have investigated XRD, XPS, FE-SEM and EDX. We have confirmed the advantage of ZnO UV sensor for wearable computing devices.