In this paper, we developed a low-cost, simple and rapid fabrication for PrTi_xO_y electrolyte-insulator-semiconductor (EIS) sensors by sol-gel spin-coating technique. The influence of praseodymium content on the structural properties and sensing characteristics of PrTi_xO_y sensing membranes was explored. We used X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy to examine the structural, morphological and chemical features of these films as functions of the growth conditions (Pr concentrations ranging from 0.1 to 0.3 M), respectively.The observed structural properties were then correlated with their sensing performances. The PrTi_xO_y EIS device treated at a Pr concentration of 0.2 M with showed the best sensing characteristics, including pH sensitivity, hysteresis and drift. We attribute this behaviour to the optimal praseodymium content in the PrTi_xO_y film forming a well-crystallized Pr₂TiO₅ structure and a smoother surface.