An incremental double-layer capacitance of a planar nano gap and its application in cardiac-troponin T detection

作者：Hsueh Hsiao Ting; Lin Chih Ting^*

来源：Biosensors and Bioelectronics, 2016, 79: 636-643.

DOI：10.1016/j.bios.2015.12.105

• Surface potential
• Electric double layer capacitance
• Cyclic voltammetry
• Biosensor
• Nano-gap
• Coplanar electrode

Surface potential is one of the most important properties at solid liquid interfaces. It can be modulated by the voltage applied on the electrode or by the surface properties. Hence, surface potential is a good indicator for surface modifications, such as biomolecular bindings. In this work, we proposed a planar nano-gap structure for surface-potential difference monitoring. Based on the proposed architecture, the variance of surface-potential difference can be determined by electrical double layer capacitance (EDLC) between the nano-gap electrodes. Using cyclic voltammetry method, in this work, we demonstrated a relationship between surface potential and EDLC by chemically modifying surface properties. Finally, we also showed the proposed planar nano-gap device provides the capability for. cardiac-troponin T (cTnT) measurements with co-existed 10 mu g/ml BSA interference. The detection dynamic range is from 100 pg/ml to 1 mu g/ml. Based on experimental results and extrapolation, the detection limit is less than 100 pg/ml in diluted PBS buffer (0.01X PBS). These results demonstrated the planar nano-gap architecture having potentials on biomolecular detection through monitoring of surface-potential variation.

• 出版日期2016-5-15
• 单位中国科学院电工研究所