追踪特定分子（如药物、代谢物和生物标志物）在活体中的水平，以实时和长时间的方式，将改善我们对健康的理解以及诊断、治疗和监测疾病的能力。为此，我们正在开发基于电化学适体酶（EAB）的生物传感器，这是一个支持高频率、实时分子测量的通用平台，可用于活体。在这里，我们报告了在活体中部署的EAB传感器中使用琼脂糖水凝胶保护层显著改善了其信号稳定性。这种改进的稳定性足够使这些水凝胶保护的传感器在静脉、肌肉、膀胱或肿瘤等活体部位部署时实现了良好的基线稳定性和精确性，而无需传统上在这种部署中所需的漂移校正方法。最后，我们的植入式凝胶保护EAB传感器在活体大鼠中部署时表现出良好的生物相容性，不会引起严重炎症。

The ability to track the levels of specific molecules, such as drugs, metabolites, and biomarkers, in the living body, in real time and for long durations, would improve our understanding of health and our ability to diagnose, treat, and monitor disease. To this end, we are developing electrochemical aptamer-based (EAB) biosensors, a general platform supporting high-frequency, real-time molecular measurements in the living body. Here we report that the use of an agarose hydrogel protective layer for EAB sensors significantly improves their signaling stability when deployed in the complex, highly time-varying environments found in vivo. The improved stability is sufficient that these hydrogel-protected sensors achieved good baseline stability and precision when deployed in situ in the veins, muscles, bladder, or tumors of living rats without the use of the drift correction approaches traditionally required in such placements. Finally, our implantable gel-protective EAB sensors achieved good biocompatibility when deployed in vivo in the living rats without causing any severe inflammation.