Breakthrough Blocking-Layer Stability for Broader Clinical Utility of Continuous Aptamer Biosensors

项目总结 使用10-14天连续血糖监测仪进行糖尿病治疗是一项历史性的成就 现代诊断，但不幸的是，它仍然是一个孤立的成功，尽管迫切需要实时 在更广泛的人类疾病管理领域(心脏、药物)监测许多其他分子 剂量、生育能力等)。限制是葡萄糖传感器是酶的，限制了它们对其他 分析物(即酶氧化/还原目标分子)。与酶传感器不同，电化学传感器 基于适配子的(EAB)传感器具有广泛的普适性，通过几个实时、实时、快速的例子证明了这一点 从纳摩尔到微摩尔浓度的活体分子监测。不幸的是，体内设备的寿命 EAB传感器的临床应用仍然是一个重大挑战。 EAB传感器通常使用氧化还原标记适体和烷基硫醇封闭分子的单层 金工作电极。这些自组装单分子膜(SAM)实际上在金电极上迅速降解 体温为37℃的生物体液。EAB自组装膜的降解机理尚不清楚。 在复杂的生物体液中被理解，这就限制了追求延长寿命的技术的能力。我们的 初步数据现在为了解SAM降解的真正机制提供了重要的见解。随着这一点的改进 了解了降解，ITS现在可以追求至少5天的稳定运行。多天 然后，操作将使EABs能够可靠地用于葡萄糖以外的应用，并首次， 可以开始进行适当的研究，以解决下一个预期的寿命瓶颈，这可能会防止1-2 周操作(例如，污垢、核酸酶攻击等)。 中心假设是至少5天的EAB传感器操作可以通过阻塞层实现 具有通过以下任一方式获得的卓越稳定性：(1)在传感器期间电化学稳定烷基硫醇封闭层 制造，或(2)用具有类似密度的无机介质膜来取代烷基硫醇阻隔层 支持有效电子转移的缺陷。5天的手术将带来临床相关性的飞跃， 并且是典型的6-12小时限制的10-20倍。5天的操作将使Pi Heikenfeld定位到 继续进行临床研究，并将点燃与葡萄糖传感器行业领先者迫切需要的合作伙伴关系。 Pi Heikenfeld是NIH的一名新研究员，但考虑到他的 在生物传感器方面拥有深厚的专业知识，他的同事皮特·怀特和波特在EAB传感器和电化学方面的专业知识 阻挡层。

PROJECT SUMMARY The use of 10-14 day continuous glucose monitors for diabetes management is a historical achievement in modern diagnostics, but unfortunately it remains an isolated success despite acute needs for the real-time monitoring of many other molecules across the broader field of human disease management (cardiac, drug dosing, fertility, etc.). The limitation is that glucose sensors are enzymatic, limiting their generalizability to other analytes (i.e., enzymes oxidize/reduce the target molecule). Unlike enzymatic sensors, electrochemical aptamer-based (EAB) sensors are broadly generalizable, demonstrated by several examples of real-time, in- vivo molecular monitoring at nanomolar to micromolar concentrations. Unfortunately, in-vivo device longevity remains a significant challenge for the clinical adoption of EAB sensors. EAB sensors conventionally use a monolayer of redox-tagged aptamers and alkylthiol blocking molecules on a gold working electrode. These self-assembled monolayers (SAMs) rapidly degrade on gold electrodes in real biofluids at body temperature of 37 °C. The mechanisms of degradation of EAB SAMs have not been well- understood in complex biofluids, which then limits the ability to pursue techniques to improve longevity. Our preliminary data now provides major insights into the true mechanisms of SAM degradation. With this improved understanding of degradation, its is now feasible to pursue stable operation for at least 5 days. Multi-day operation would then allow EABs to be credibly pursued for applications beyond glucose, and for the first time, proper research could begin on resolving the next expected longevity bottlenecks that would likely prevent 1-2 week operation (e.g. fouling, nuclease attack, etc.). The central hypothesis is that at minimum 5 day EAB sensor operation can be achieved through a blocking layer with superior stability achieved by either (1) electrochemically stabilizing an alkylthiol blocking layer during sensor fabrication, or (2) replacing an alkylthiol blocking layer with a inorganic dielectric film that has a similar density of defects supporting efficient electron transfer. 5 day operation would provide a leap forward in clinical relevance, and is 10-20X greater the typical limit of 6-12 hours. 5 day operation would then position the PI Heikenfeld to pursue clinical research, and would ignite critically-needed partnerships with industry leaders in glucose sensors. The PI Heikenfeld is a new NIH investigator, but is well-prepared to pursue this longevity breakthrough given his deep expertise in biosensors, and his co-PI’s White and Porter’s expertise in EAB sensors and electrochemical blocking layers.