Implantable electrochemical biosensors: Challenges, strategies, and applications

Applying biosensor technologies to continuous, real-time measurements in living creatures, including humans, offers an exciting range of possibilities for a better understanding of both normal physiology and disease. It also comes with a collection of technical, ethical and regulatory needs that render the transition of electrochemical biosensors from in vitro to in vivo exceptionally challenging. In this review, we address the advances in the components of implantable electrochemical biosensors. These include the integration of molecular recognition elements, materials design, supply of electrical power, fabrication of instrumentation packages and communications protocols. Significant challenges that remain include those associated with biocompatibility, sterility, device lifetime, calibration and user acceptability. Regulatory aspects whether of medical or consumer devices are essential to address and need to be an early consideration in device design, as are the use cases to which the implanted sensor will ultimately address. • Key advances from recent research on implantable electrochemical biosensors. • Smart coatings reduce Foreign Body Response, extending sensor life beyond 3 weeks. • Continuous glucose monitoring leads IEBs advances with enhanced accuracy. • Smart biodegradable materials eliminate need for sensor removal surgery. • Power management remains critical despite advances in energy harvesting methods.