Department of Materials Science and Engineering, National Tsing-Hua University (NTHU), Hsinchu 30013, Taiwan.
Biosens Bioelectron. 2011 Jun 15;26(10):4124-32. doi: 10.1016/j.bios.2011.04.003. Epub 2011 Apr 12.
This paper reports the success of amino-functionalization on multi-walled carbon nanotubes (MWCNTs) to promote neuronal cells growth on MWCNT electrode for extracellular recording, attributed to the formation of positive charge of NH(2) molecules on their surfaces. Besides, the surface of MWCNT electrode becomes hydrophilic after amino-functionalization (AF-MWCNTs) which can enhance electrical conductivity because of lower MWCNT/electrolyte interfacial impedance and higher interfacial capacitance. Durability tests show that electrical characteristics of the MWCNTs treated by 2 wt% 1,4-diaminobutane solution (2 wt%-AF-MWCNTs) can last for at least six months in air ambient. The neural recording of crayfish shows that 2 wt%-AF-MWCNTs can provide better capability on detecting action potentials of caudal photoreceptor (CPR) interneuron compared to suction glass pipette from the evidence of a higher S/N ratio (126 versus 23). The amino-functionalized MWCNT electrode is feasible for long-term recording application according to the results of biocompatibility tests. As the MWCNTs were directly synthesized on Si-based substrates by catalyst-assisted thermal chemical vapor deposition (CVD) at a low temperature (400 °C), these self-aligned MWCNT electrodes could be friendly implemented in integrated circuits fabrications.
本文报道了多壁碳纳米管（MWCNTs）的成功氨基功能化，以促进神经元细胞在 MWCNT 电极上的生长，用于细胞外记录，这归因于其表面 NH(2)分子形成正电荷。此外，MWCNT 电极经过氨基功能化（AF-MWCNTs）后变得亲水，因为 MWCNT/电解质界面阻抗降低和界面电容增加，从而提高了电导率。耐久性测试表明，在空气中，经过 2wt%1,4-二氨基丁烷溶液处理的 MWCNTs（2wt%-AF-MWCNTs）的电特性至少可以持续六个月。对小龙虾的神经记录表明，与玻璃吸管相比，2wt%-AF-MWCNTs 可以通过更高的信噪比（126 比 23）提供更好的检测尾光感受器（CPR）中间神经元动作电位的能力。根据生物相容性测试的结果，氨基功能化的 MWCNT 电极适用于长期记录应用。由于 MWCNTs 是通过催化剂辅助的热化学气相沉积（CVD）在低温（400°C）下直接在 Si 基衬底上合成的，因此这些自对准 MWCNT 电极可以友好地集成在集成电路制造中。
