The College of Science at Basra University organized a seminar (Sensing Application Based on ZnO Nanorods Synthesis by Chemical Bath Deposition) for the graduate student/Ph.D. "Salah Mahdi Salih" The study aims to synthesis UV photodetectors and gas sensors based on ZnO nanorods deposited on different substrates: (hard and flexible substrates) by CBD method. This method is characterized by its ease of use and its low cost while preserving the quality of thin film. The study included the importance of ZnO, its preparation methods and uses, and the importance of using flexible substrates for preparing sensors. As well as, set of results were presented on preparing UV photodetectors based on ZnO NRs deposited on the above-mentioned substrates with good properties (photoresponse, sensitivity, selectivity and efficiency).