Cytochrome c-Mediated Dual Functions for Real-Time ROS Monitoring and Sustainable Energy Supply in Implantable Device

Abstract

Abstract Smart stents integrate embedded sensors and advanced technology, providing a real-time diagnostic feedback, particularly for detection of thrombotic events. A continuous monitoring reactive oxygen species (ROS) in blood vessels is crucial for cardiovascular disease. The provision of a continuous power supply to sensors integrated within blood vessels is challenging. This study introduces a novel device that combines a sensor and supercapacitor, functioning as a ROS sensor and enabling continuous charging and discharging within blood vessels. This device employs thread-shaped electrodes integrated with cytochrome c and carbon nanotubes (Cyt.c/CNT). The Cyt.c/CNT electrode exhibits a high specificity to ROS with an excellent sensitivity (49.02 µAµM− 1cm− 2), as a real-time biosensor for monitoring of cellular ROS levels in living cells. In addition, it exhibited an energy storage performance of 257.95 mF/cm2 as a supercapacitor and maintained a stable performance during 10,000 repeated cycles in various biofluids. Notably, the integration of the Cyt.c/CNT electrode with an enzymatic biofuel cell enables continuous charging and discharging in a biofluid, making it a promising system for in-vivo applications such as smart stents. This study presents the potential of the biomaterial Cyt.c for ROS sensing as well as its potential as an energy storage system, showing new possibilities for implantable devices for cardiovascular diseases.