A biochemical sensor with continuous extended stability in vivo.

The development of biosensors that can detect specific analytes continuously, in vivo, in real time has proven difficult due to biofouling, probe degradation and signal drift that often occur in vivo. By drawing inspiration from intestinal mucosa that can protect host cell receptors in the presence of the gut microbiome, we develop a synthetic biosensor that can continuously detect specific target molecules in vivo. The biomimetic multicomponent sensor features the hierarchical nano-bio interface design with three-dimensional bicontinuous nanoporous structure, polymer coating and aptamer switches, balancing small-molecule sensing and surface protection in complex biological environments. Our system is stable for at least 1 month in undiluted serum in vitro or 1 week implanted within the blood vessels of free-moving rats, retaining over 50% baseline signal and reproducible calibration curves. We demonstrate that the implanted system can intravenously track pharmacokinetics in real time even after 4 days of continuous exposure to flowing blood within rat femoral vein. In this way, our work provides a generalizable design foundation for biosensors that can continuously operate in vivo for extended durations.