Hydrophilic modification of neural microelectrode arrays based on multi-walled carbon nanotubes
Hydrophilic modification of neural microelectrode arrays based on multi-walled carbon nanotubes
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DOI：
10.1088/0957-4484/21/48/485501
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发表时间：
2010-12-03
期刊：
影响因子：
3.5
通讯作者：
Yao, Da-Jeng
中科院分区：
文献类型：
--
作者：
Chen, Chang-Hsiao;Su, Huan-Chieh;Yao, Da-Jeng
为了降低微电极阵列的阻抗，在神经科学应用中，我们制作并测试了基于多壁碳纳米管的微电极阵列。微电极的物理尺寸越小，其阻抗越大，电荷传递能力越弱。为了减小阻抗，通常必须增加电极的有效表面积。我们探讨了等离子体处理对MWCNT表面润湿性的影响。通过蒸汽等离子体处理，MWCNT表面由超疏水性转变为超亲水性；这种亲水性归因于MWCNT表面的-OH键。本文报道了采用热化学气相沉积法在400℃下在镍钛多层金属催化剂上合成MWCNT。施加功率小于25 W的等离子体10 s，提高了电化学和生物性能，并绕过了表面恢复疏水状态的限制；亲水性至少维持一个月。用MEA记录了美洲小龙虾侧边巨细胞的神经信号。动作电位的响应幅值约为275 μ V，周期为1ms；记录的数据信噪比高达40.12 dB。电极性能的提高使神经信号的分离和不同形状的识别成为可能。随着进一步的发展，快速处理将有助于长期记录应用。
To decrease the impedance of microelectrode arrays, for neuroscience applications we have fabricated and tested MEA based on multi-walled carbon nanotubes. With decreasing physical size of a microelectrode, its impedance increases and charge-transfer capability decreases. To decrease the impedance, the effective surface area of the electrode must generally be increased. We explored the effect of plasma treatment on the surface wettability of MWCNT. With a steam-plasma treatment the surface of MWCNT becomes converted from superhydrophobic to superhydrophilic; this hydrophilic property is attributed to -OH bonding on the surface of MWCNT. We reported the synthesis at 400 degrees C of MWCNT on nickel-titanium multilayered metal catalysts by thermal chemical vapor deposition. Applying plasma with a power less than 25 W for 10 s improved the electrochemical and biological properties, and circumvented the limitation of the surface reverting to a hydrophobic condition; a hydrophilic state is maintained for at least one month. The MEA was used to record neural signals of a lateral giant cell from an American crayfish. The response amplitude of the action potential was about 275 mu V with 1 ms period; the recorded data had a ratio of signal to noise up to 40.12 dB. The improved performance of the electrode makes feasible the separation of neural signals and the recognition of their distinct shapes. With further development the rapid treatment will be useful for long-term recording applications.