Long-Term Molecular Monitoring in Complex Biological Environments

Long-term molecular monitoring in complex biological environments is crucial for understanding, preventing, diagnosing, and managing human diseases. Aptamer-based electrochemical biosensors hold promise due to their generalizability and high degree of selectivity. However, existing aptamer-based biosensors face challenges in complex biological environments due to the monolayer loss, aptamer degradation, and biofouling. To address this, we present a surface coating designed to improve the longevity of aptamer-based biosensors in such environments. We demonstrate the application of these surface coatings to various aptamer-based biosensors for detecting drugs (e.g., fentanyl) and neurotransmitters (e.g., dopamine) in undiluted whole blood samples. MTT analysis of forebrain spheroids cocultured with these coatings and in vivo immunohistochemistry studies indicate their biocompatibility for use in real-time, in vivo molecular monitoring. The results establish the potential for chronic aptamer-based molecular monitoring platforms.