Bioelectronic Sutures with Electrochemical pH-Sensing for Long-Term Monitoring of the Wound Healing Progress

The physiological pH level at wound sites is one of the fundamental factors for monitoring wound conditions in clinical practice. To continuously assess the wound conditions, a variety of bioelectronic pH sensors are extensively developed. However, despite significant advances in bioelectronics for wound monitoring, the application of existing bioelectronic devices, primarily designed as bandages or patches, remains challenging for monitoring pH levels in deep wounds. Here, a flexible pH-sensing suture is introduced that can be simultaneously used as both a precise pH sensor for wound monitoring and a conventional medical suture. The electrochemical pH-sensing suture comprises Au nanoparticle-based flexible electrodes functionalized with polyaniline for the working electrode and Ag/AgCl for the reference electrode, seamlessly integrated onto a standard medical suturing thread. This dual-function sensing suture offers a reliable and high sensitivity of 58.9 mV pH⁻¹, negligible hysteresis, high stability, and excellent selectivity in pH sensing. The biocompatibility of the sensing suture is systematically verified for its in vivo use. To demonstrate the capabilities of the pH-sensing suture, it is successfully applied to an incision and chronic wound model of mouse to perform continuous and accurate monitoring of the inflammation and healing progress of the wound throughout the healing period.