Department of Chemistry, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States.
Department of Electrical & Computer Engineering, University of Minnesota , 200 Union Street SE, Minneapolis, Minnesota 55455, United States.
ACS Appl Mater Interfaces. 2017 Nov 8;9(44):38863-38869. doi: 10.1021/acsami.7b14864. Epub 2017 Oct 24.
A novel graphene-based variable capacitor (varactor) that senses glucose based on the quantum capacitance effect was successfully developed. The sensor utilizes a metal-oxide-graphene varactor device structure that is inherently compatible with passive wireless sensing, a key advantage for in vivo glucose sensing. The graphene varactors were functionalized with pyrene-1-boronic acid (PBA) by self-assembly driven by π-π interactions. Successful surface functionalization was confirmed by both Raman spectroscopy and capacitance-voltage characterization of the devices. Through glucose binding to the PBA, the glucose concentration in the buffer solutions modulates the level of electrostatic doping of the graphene surface to different degrees, which leads to capacitance changes and Dirac voltage shifts. These responses to the glucose concentration were shown to be reproducible and reversible over multiple measurement cycles, suggesting promise for eventual use in wireless glucose monitoring.
成功开发了一种基于石墨烯的新型变容器（varactor），该变容器基于量子电容效应来感测葡萄糖。该传感器利用金属氧化物-石墨烯变容器器件结构，该结构与无源无线感测固有兼容，这是体内葡萄糖感测的一个关键优势。通过π-π相互作用驱动的自组装，将芘-1-硼酸（PBA）功能化到石墨烯变容器上。通过拉曼光谱和器件的电容-电压特性来确认成功的表面功能化。通过 PBA 与葡萄糖的结合，缓冲溶液中的葡萄糖浓度以不同程度调制石墨烯表面的静电掺杂水平，从而导致电容变化和狄拉克电压偏移。这些对葡萄糖浓度的响应在多次测量循环中表现出可重复性和可还原性，这表明有望最终用于无线葡萄糖监测。
