Embodiments of the present invention are directed to a system for sensing urine pH. A non-limiting example of the system includes a urinary catheter tube for insertion into a bladder of a patient, wherein the urine catheter tube includes an inner cavity. The system also includes a collection vessel connected to the urinary catheter tube. The system also includes a FET-based pH sensing device including a pH sensing surface and a reference electrode, wherein the pH sensing surface and the reference electrode have a surface exposed to the inner cavity. Such embodiments can advantageously provide a real-time, sensitive measurement of urine for timely detection and monitoring of the physiological condition of a subject with a miniaturized FET-based pH sensor.
