A robust Au–CC anchoring group greatly improves the signal stability of electrochemical aptamer-based sensors for in vivo measurements

Abstract

The ability to monitor drug pharmacokinetics in real time and directly in vivo is critical to achieve therapeutic efficacy and personalized medicine. Electrochemical aptamer-based (EAB) sensors have emerged as a promising platform for this purpose, yet their long-term stability is compromised by the degradation of the conventional Au–S bond-based bioelectronic interface under continuous interrogation. To address this fundamental limitation, we introduced an approach based on an Au–CC anchoring group to create a significantly more robust sensing interface. This stable configuration enabled our sensors to retain 92% signal integrity over 72 hours (>6000 scans) in whole blood. Leveraging this exceptional stability, we successfully achieved real-time tracking of drug concentrations in live rats, demonstrating a significant advance toward continuous pharmacokinetic monitoring.