Banno Tomoaki, Tsuruhara Shuhei, Seikoba Yu, Tonai Ryohei, Yamashita Koji, Idogawa Shinnosuke, Kita Yuto, Suzuki Ko, Yagi Yuki, Kondo Yuki, Numano Rika, Koida Kowa, Kawano Takeshi
Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan.
Electronics-Inspired Interdisciplinary Research Institute, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan.
ACS Nano. 2022 Jul 26;16(7):10692-10700. doi: 10.1021/acsnano.2c02399. Epub 2022 Jul 5.
Microscale needle-like electrode technologies offer extracellular recording with a high spatiotemporal resolution. Further miniaturization of needles to nanoscale minimizes tissue injuries; however, a reduced electrode area increases electrical impedance that degrades the quality of neuronal signal recording. We overcome this limitation by fabricating a 300 nm tip diameter and 200 μm long needle electrode where the amplitude gain with a high-impedance electrode (>15 MΩ, 1 kHz) was improved from 0.54 (-5.4 dB) to 0.89 (-1.0 dB) by stacking it on an amplifier module of source follower. The nanoelectrode provided the recording of both local field potential (<300 Hz) and action potential (>500 Hz) in the mouse cortex, in contrast to the electrode without the amplifier. These results suggest that microelectrodes can be further minimized by the proposed amplifier configuration for low-invasive recording and electrophysiological studies in submicron areas in tissues, such as dendrites and axons.
微尺度针状电极技术可提供具有高时空分辨率的细胞外记录。将针进一步微型化至纳米尺度可使组织损伤最小化；然而，电极面积减小会增加电阻抗，从而降低神经元信号记录的质量。我们通过制造一种尖端直径为300 nm、长度为200 μm的针状电极克服了这一限制，将其堆叠在源极跟随器的放大器模块上时，高阻抗电极（>15 MΩ，1 kHz）的幅度增益从0.54（-5.4 dB）提高到了0.89（-1.0 dB）。与没有放大器的电极相比，该纳米电极能够记录小鼠皮层中的局部场电位（<300 Hz）和动作电位（>500 Hz）。这些结果表明，通过所提出的放大器配置，微电极可进一步微型化，以用于组织中亚微米区域（如树突和轴突）的低侵入性记录和电生理研究。
