Malkoc Aldin, Probst David, Lin Chi, Khanwalker Mukund, Beck Connor, Cook Curtiss B, La Belle Jeffrey T
1 School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA.
2 Mayo Clinic Arizona, Scottsdale, AZ, USA.
J Diabetes Sci Technol. 2017 Sep;11(5):930-935. doi: 10.1177/1932296817699639. Epub 2017 Mar 16.
Currently, glycemic management for individuals with diabetes mellitus involves monitoring glucose only, which is insufficient as glucose metabolism involves other biomarkers such as insulin. Monitoring additional biomarkers alongside glucose has been proposed to improve glycemic control. In this work, the development of a rapid and label-free insulin biosensor with high sensitivity and accuracy is presented. The insulin sensor prototype also serves as a prior study for a multimarker sensing platform technology that can further improve glycemic control in the future.
Electrochemical impedance spectroscopy was used to identify an optimal frequency specific to insulin detection on a gold disk electrode with insulin antibody immobilized, which was accomplished by conjugating the primary amines of insulin antibody to the carboxylic bond of the self-assembling monolayer on the gold surface. After blocking with ethanolamine, the insulin physiological concentration gradient was tested. The imaginary impedance was correlated to insulin concentration and the results were compared with standard equivalent circuit analysis and correlation of charge transfer resistance to target concentration.
The optimal frequency of insulin is 810.5 Hz, which is characterized by having the highest sensitivity and sufficient specificity. The lower limit of detection was 2.26 [Formula: see text] which is comparable to a standard and better than traditional approaches.
An insulin biosensor prototype capable of detecting insulin in physiological range without complex data normalization was developed. This prototype will be the ground works of a multimarker platform sensor technology for future all-in-one glycemic management sensors.
目前，糖尿病患者的血糖管理仅涉及监测血糖，而由于葡萄糖代谢涉及胰岛素等其他生物标志物，这种方式并不充分。有人提出同时监测葡萄糖及其他生物标志物以改善血糖控制。在本研究中，我们展示了一种具有高灵敏度和准确性的快速、无标记胰岛素生物传感器的研发成果。该胰岛素传感器原型也是对一种多标志物传感平台技术的前期研究，该技术未来可进一步改善血糖控制。
采用电化学阻抗谱在固定有胰岛素抗体的金盘电极上确定特定于胰岛素检测的最佳频率，这是通过将胰岛素抗体的伯胺与金表面自组装单层的羧基键结合来实现的。用乙醇胺封闭后，测试胰岛素生理浓度梯度。将虚部阻抗与胰岛素浓度相关联，并将结果与标准等效电路分析以及电荷转移电阻与目标浓度的相关性进行比较。
胰岛素的最佳频率为810.5 Hz，其特点是具有最高灵敏度和足够的特异性。检测下限为2.26 [公式：见正文]，与标准相当且优于传统方法。
我们开发了一种能够在生理范围内检测胰岛素且无需复杂数据归一化的胰岛素生物传感器原型。该原型将成为未来一体化血糖管理传感器的多标志物平台传感器技术的基础工作。
