This paper presents a dielectric affinity microsensor that consists of an in situ prepared hydrogel attached to a pair of coplanar electrodes for dielectrically based affinity detection of glucose in subcutaneous tissue in continuous glucose monitoring applications. The hydrogel, incorporating N-3-acrylamidophenylboronic acid that recognizes glucose via affinity binding, is synthetically prepared on the electrodes via in situ gelation. When implanted in subcutaneous tissue, glucose molecules in interstitial fluid diffuse rapidly through the hydrogel and bind to the phenylboronic acid moieties. This induces a change in the hydrogel's permittivity and hence in the impedance between the electrodes, which can be measured to determine the glucose concentration. The in situ hydrogel preparation allows for a reduced hydrogel thickness (~10 μm) to enable the device to respond rapidly to glucose concentration changes in tissue, as well as covalent electrode attachment of the hydrogel to eliminate the need for semipermeable membranes that would otherwise be required to restrain the sensing material within the device. Meanwhile, the use of coplanar electrodes is amenable to the in situ preparation and facilitates glucose accessibility of the hydrogel, and combined with dielectrically based transduction, also eliminates mechanical moving parts often found in existing affinity glucose microsensors that can be fragile and complicated to fabricate. Testing of the device in phosphate-buffered saline at pH 7.4 and 37 °C has shown that at glucose concentrations ranging from 0 to 500 mg/dL, the hydrogel-based microsensor exhibits a rapid, repeatable, and reversible response. In particular, in the glucose concentration range of 40-100 mg/dL, which is of great clinical interest to monitoring normal and low blood sugar levels, the device response is approximately linear with a resolution of 0.32 mg/dL based on effective capacitance and 0.27 mg/dL based on effective resistance, respectively. Thus, the device holds the potential to enable reliable and accurate continuous monitoring of glucose in subcutaneous tissue.

中文翻译：

---

使用水凝胶功能化共面电极的介电亲和力葡萄糖微传感器。

本文提出了一种介电亲和力微传感器，该传感器由原位制备的水凝胶组成，该水凝胶附着在一对共面电极上，用于在连续葡萄糖监测应用中皮下组织中葡萄糖的介电基亲和力检测。通过原位凝胶化在电极上合成制备水凝胶，该水凝胶结合了可通过亲和力结合识别葡萄糖的N-3-丙烯酰胺基苯基硼酸。当植入皮下组织时，组织液中的葡萄糖分子迅速扩散通过水凝胶并结合至苯基硼酸部分。这引起水凝胶的介电常数的变化，并因此引起电极之间的阻抗的变化，可以测量该变化以确定葡萄糖浓度。原位水凝胶制备允许减小的水凝胶厚度（〜10μm），以使设备能够快速响应组织中的葡萄糖浓度变化，以及水凝胶的共价电极连接，从而消除了对半透膜的需求需要将传感材料限制在设备内。同时，共面电极的使用适合于原位制备并且促进水凝胶的葡萄糖可及性，并且与基于电介质的转导相结合，还消除了现有的亲和力葡萄糖微传感器中经常发现的机械运动部件，该机械运动部件可能易碎且制造复杂。在pH 7.4和37°C的磷酸盐缓冲盐水中对设备进行测试，结果表明，在葡萄糖浓度为0至500 mg / dL的情况下，基于水凝胶的微传感器表现出快速，可重复和可逆的响应。特别是，在40-100 mg / dL的葡萄糖浓度范围内，这对于监测正常和低血糖水平具有重大的临床意义，基于有效电容和负压，设备响应近似线性，分辨率为0.32 mg / dL。基于有效电阻分别为0.27 mg / dL。因此，该装置具有实现可靠且准确的连续皮下组织葡萄糖监测的潜力。基于有效电阻分别为27 mg / dL。因此，该装置具有实现可靠且准确的连续皮下组织葡萄糖监测的潜力。基于有效电阻分别为27 mg / dL。因此，该装置具有实现可靠且准确的连续皮下组织葡萄糖监测的潜力。