碳奈米管場效應電晶體用於神經活性之研究

本論文藉由網路型單壁碳奈米管場效應電晶體(single wall carbon nanotubes field effect transistor，SWNT-FET)生物感測器，偵測大腦神經細胞在神經傳導過程中所釋放出來的嗜鉻粒蛋白Ａ，作為細胞的神經活性之指標。　　我們藉由奈米機電製程技術來製備網路型SWNT-FET，並從電流－閘極電壓特性圖的分析中，鑑定我們的SWNT-FET為p型半導體傳輸特性。接著，藉由非共價鍵官能性pyrene修飾法將SWNT-FET修飾上嗜鉻粒蛋白A的抗體，使其成為對嗜鉻粒蛋白A靈敏的SWNT-FET生物感測器。在進行到結合神經細胞的實驗之前，我們以市面所購得的嗜鉻粒蛋白Ａ胜肽(158 ~ 457胺基酸)作測試。從其與其抗體間分子辨識的實驗結果中，我們能夠量測到 1 nM的偵測極限。此外，我們從由對電場感應程度不同的元件之實驗結果比較中，推斷出偵測機制是透過化學閘極效應，以及調變穿隧效應機率兩者結合的結果。　　更進ㄧ步地我們將實驗拓展至生物系統上。藉由量測不同生理活性的大腦神經細胞在接觸SWNT-FET的過程中所造成的電性變化，我們推斷出電性變化與神經細胞的生理活性有關，可能包含的原因是膜電位與細胞膜的電偶極。接著，在藉由以免疫染色與西方轉自法確定嗜鉻粒蛋白A大量存在於神經細胞之後,我們以麩氨酸活化大腦神經細胞,藉由SWNT-FET即時並選擇性地偵測到大腦神經細胞在神經傳導過程中所釋放出來的嗜鉻粒蛋白Ａ。此結果代表著我們成功地將SWNT-FET生物感測器的技術推廣到了活體神經細胞的神經傳導研究上，我們也相信將來這技術能夠拓展到個別的單隻神經細胞之研究，為了解整個神經細胞網路的神經生理學打開了一扇嶄新的視窗。

關鍵字

場效應電晶體；神經活性；神經傳導；嗜鉻粒蛋白A

並列摘要

We investigated the synaptic transmissions among primary cultured embryonic cortical neurons by using network single wall carbon nanotube field effect transistors (NSWNT-FET). We selectively monitored the chromogranin A (CgA) released by neuronal cells during the synaptic transmission process as an index of the neuronal activity. We use microelectronic techniques to fabricate NSWNT-FET devices, and the electrical transport in the NSWNT-FET was characterized by measuring the source-drain current vs. back-gate voltage (I-Vg curves). The results indicated that the NSWNT-FET is a p-type semiconductive device. Before applying this technique to living neuron cells, we conducted the standard molecular recognition experiment of CgAP (CgA peptide, 158~457 AA) and CgA-Ab (chromogranin A antibody) to test the performance of NSWNT-FET and investigate the sensing mechanism. The results showed sensitive electric responses, thus demonstrating the high affinity between CgAP and CgAP-Ab. The sensing mechanism was attributed to both chemical gating effect and thining of Schottky barrier between metal electrode and NSWNTs. In the present result, the detection limit of CgAP was 1 nM. 　　　　To verify the feasibility of applying this novel system to detect the CgA secreted from cultured cortical neurons, we used immunochemistry and Western blot to confirm the existence of CgA in neuronal cells. Both result showed CgA was abundant in the whole cell, including soma and neuritis. To extend the detection of CgA to living neuronal cells, we used glutamate to stimulate the neurons and successfully detected the CgA released during the synaptic transmission processes. The result demonstrated that CgA released from the synaptic terminal of neurons can be detected directly with high selectivity and sensitivity by CgA-Ab modified NSWNT-FET. This sensory technique is promising in medical examination and the study of individual neuron cell activity, which should open a new window to understand the neurophysiology in neuronal network.

並列關鍵字

field effect transistor ； neuronal activities ； chromogranin A

參考文獻

2. M. Voelker, P. Fromherz. Small, 2005, 1, 206. Signal Transmission from Individual Mammalian Nerve Cell to Field-Effect Transistor.

3. M. Merz, P. Fromherz. Adv. Funct. Mater. 2005, 15, 739. Silicon chip interfaced with a geometrically defined net of snail neurons .

4. G. Steinhoff, B. Baur, G. Wrobel, S. Ingebrandt, A. Offenhäusser, A. Dadgar, A. Krost, M. Stutzmann, M. Eickhoffa. Appl. Phys. Lett. 2005, 86, 033901. Recording of cell action potentials with AlGaN/GaN field-effect transistors.

5. Y. Cui, Q. Wei, H. Park, C. M. Lieber. Science. 2001, 293, 1289. Nanowire Nanosensors for Highly Sensitive and Selective Detection of Biological and Chemical Species.

6. R. J. Chen, H. C. Choi,, S. Bangsaruntip, E. Yenilmez,, X. Tang, Q. Wang, Y. Chang, H. Dai. J. Am. Chem. Soc. 2004, 126, 1563. An Investigation of the Mechanisms of Electronic Sensing of Protein Adsorption on Carbon Nanotube Devices

國際替代計量

碳奈米管場效應電晶體用於神經活性之研究

全文下載

主題瀏覽