The pH of the gastrointestinal (GI) tract has strong correlation with many GI diseases. In this study, a wireless and ingestible capsule system for monitoring GI pH was reported. Iridium oxide was electrodeposited on the screen-printed electrode (SPE) to form the pH sensor, which had the high sensitivity and wide detection range for H⁺. The rigid-flexible composited printed circuit board (RFPCB) technique was used to design the capsule detection circuit. Both of them were encapsulated into the 3D-printed capsule structure. With the biocompatibility treatment, the entire capsule system could be obtained, whose diameter and height were ~14.5 mm and ~26 mm, respectively. The capsule system could be ingested into the GI tract to perform real-time pH detection of biofluids, and the detected signal could be wirelessly transmitted to the external receiving device, which could be smartphone, personal computer, or the auxiliary circuit for wireless communication. In the in vivo evaluation of large animal, the capsule system could detect the pH of GI tract in real time, whose detection results were close to that of the professional pH instrument. Thus, the capsule system had the practical application potential of assisting in the clinical diagnosis of GI diseases.

胃肠 (GI) 道的 pH 值与许多胃肠道疾病有很强的相关性。在这项研究中，报告了一种用于监测 GI pH 值的无线和可摄入胶囊系统。将氧化铱电沉积在丝网印刷电极 (SPE) 上形成 pH 传感器，该传感器对 H ⁺具有高灵敏度和宽检测范围. 采用刚柔复合印刷电路板（RFPCB）技术设计胶囊检测电路。它们都被封装在 3D 打印的胶囊结构中。通过生物相容性处理，可以获得整个胶囊系统，其直径和高度分别为~14.5 mm和~26 mm。胶囊系统可以被摄入胃肠道，对生物体液进行实时pH检测，检测信号可以无线传输到外部接收设备，可以是智能手机、个人电脑或无线通信的辅助电路。在体内对大型动物的评价，胶囊系统可以实时检测胃肠道的pH值，其检测结果与专业pH值仪的检测结果接近。因此，胶囊系统具有辅助胃肠疾病临床诊断的实际应用潜力。