Gastroesophageal reflux disease (GERD) is recognized the primary risk factor associated with esophageal cancers. Therefore, monitoring GERD symptoms accurately is important for early diagnosis of such cancers. In this work, interdigitated impedance sensing electrodes and nanofabricated IrOx-based pH sensing electrodes were made on the flexible substrates that can be easily embedded into an implantable device. The dual sensor electrodes were integrated into a batteryless wireless capsule packaged with biocompatible material for implant applications. The proposed sensing system has been tested with stimulated solutions of different pH values recording modulated sensor data in terms of frequency shifts to verify its performance. The experimental results showed that the impedance electrodes responded to ion content variations and the pH electrodes identified the pH values of various pH solutions. Our sensing system has demonstrated the ability to detect gastroesophageal reflux activities more accurately, which could help doctors to provide precise treatment methods, consequentially lowering the risks of esophageal cancer development.