Solution-Gated Graphene Field Effect Transistors Integrated in Microfluidic Systems and Used for Flow Velocity Detection
Solution-Gated Graphene Field Effect Transistors Integrated in Microfluidic Systems and Used for Flow Velocity Detection
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DOI：
10.1021/nl2040805
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发表时间：
2012-03-01
期刊：
影响因子：
10.8
通讯作者：
Yan, Feng
中科院分区：
文献类型：
--
作者：
He, Rong Xiang;Lin, Peng;Yan, Feng
将溶液门控石墨烯场效应晶体管（SGGT）集成到微流体系统中。Ag/AgCl栅电极SGGT的传输特性随微通道中KO溶液离子浓度的变化而发生水平位移，其关系可用能斯特方程拟合，这是由于Ag/AgCl电极处电位降的变化引起的。因此，栅电极是影响SGGT离子敏感性能的重要因素之一。在此基础上，基于微流控通道中流动电位的测量，将SGGT用作流速传感器。SGGT的传递曲线的偏移量与流速之间的线性关系，表明SGGT是一种很有前途的传感器，用于测量微芯片中的流速。由于流动电位受三个物理量（包括流速、流体的离子强度和基底的ζ电位）的影响，因此当其他两个量已知时，该装置可用于感测三个量中的任何一个。值得注意的是，SGGT已用于各种类型的化学和生物传感器。集成在多通道微芯片中的器件阵列在未来的芯片实验室系统中有着重要的应用前景。
Solution-gated graphene field effect transistors (SGGT) were integrated in microfluidic systems. The transfer characteristics of a SGGT with an Ag/AgCl gate electrode shifted horizontally with the change of the ionic concentration of KO solution in the microchannel and the relationship can be fitted with the Nernst equation, which was attributed to the change of the potential drop at the Ag/AgCl electrode. Therefore the gate electrode is one important factor for the ion sensitive property of the SGGT. Then SGGTs were used as flow velocity sensors, which were based on measuring the streaming potentials in microfluidic channels. A linear relationship between the shift of the transfer curve of the SGGT and the flow velocity was obtained, indicating that the SGGT is a promising transducer for measuring flow velocity in a microchip. Since the streaming potential is influenced by the three physical quantities, including the flow velocity, the ionic strength of the fluid and the zeta potential of the substrate, the device can be used for sensing any one of the three quantities when the other two were known. It is noteworthy that SGGTs have been used for various types of chemical and biological sensors. Array of the devices integrated in multichannel microchips are expected to find many important applications in the lab-on-a-chip systems in the future.