以奈米矽線場效應電晶體觀察糖水解功能

奈米矽線場效應電晶體做為偵測元件，具有高靈敏度、高選擇性、即時偵測、以及待測物不需事前修飾等特性，故常見其於偵測領域上的應用。近年來更是將奈米矽線場效應電晶體做為生物偵測器，並憑藉生物分子間專一的交互作用力，進行低濃度偵測。現有文獻中，無論是在偵測病毒、抗體、去氧核醣核酸上，或是在探討蛋白質-蛋白質、碳水化合物-蛋白質間交互作用的實驗中，皆是使用修飾在奈米線上的感測元素與待測物鍵結來產生訊號。在這類分子反應中，奈米線上的分子量會因為結合反應而變大。但有些分子反應會切斷分子而使分子量變小，我們以實驗證明既使這類反應亦可以奈米線場效應電晶進行偵測。在這論文裡，我們在奈米矽線場效應電晶體上修飾有山毛櫸木聚糖，以偵測木聚糖水解酶(TF-R8)。利用木聚糖被酵素水解之後，脫離感測範圍而使得偵測訊號改變的機制，對TF-R8進行偵測。由實驗結果得知，在酵素濃度為10 ng/ml時，本偵測系統對木聚糖水解酶仍有鑑別能力，是一個對低濃度有極高偵測能力的系統。此外，也證實了利用奈米矽線場效應電晶體來測量感測元素脫離的可行性。

關鍵字

奈米矽線場效應電晶體；山毛櫸木聚糖； 3-氨丙基三乙基矽烷； 1-乙基-3-(3-二甲基氨基丙基)碳醯二亞胺

並列摘要

Silicon nanowire field-effect transistors (SiNW-FETs) are promising real-time detectors for molecular interactions with high sensitivity and selectivity, and no prior modification of the target molecules is required. Therefore, application of SiNW-FETs in detection of biological interaction has been intensively explored in recent years. In common interactions between biologic species such as viruses, antibodies, DNA, protein or carbohydrate, the molecular binding results in an increased molecular weight, and the sensor is to detect changes in total amount of charges. However, there are interactions in which the target molecules are to cut the probe molecules, and the molecular weight reduces. In this thesis work, we test the capability for SiNW-FETs to detect this type of interactions. Specifically, xylanase (TF-R8) is detected using xylan as a probing molecule. After enzymatic hydrolysis, xylan oligosaccharide would be taken apart and move away from the SiNWs, bringing about a reduced molecular charges. This interaction can thus be detected by the SiNW-FETs. Our experiment shows adetection sensitivity for enzyme concentration down to 10ng/ml, confirming application of SiNW-FETs for enzyme-substrate hydrolytic mechanism.

並列關鍵字

Silicon nanowire field-effect-transistor ； Beechwood Xylan ； APTES ； EDC

參考文獻

1. Tans, S.J., A.R.M. Verschueren, and C. Dekker, Room-temperature transistor based on a single carbon nanotube. Nature, 1998. 393: p. 49-52.

2. Cui, Y., et al., Doping and Electrical Transport in Silicon Nanowires. The Journal of Physical Chemistry B, 2000. 104(22): p. 5213-5216.

3. Hahm, J.-i. and C.M. Lieber, Direct Ultrasensitive Electrical Detection of DNA and DNA Sequence Variations Using Nanowire Nanosensors. Nano letters, 2004. 4(1): p. 51-54.

4. Ishikawa, F.N., et al., Label-Free, Electrical Detection of the SARS Virus N-Protein with Nanowire Biosensors Utilizing Antibody Mimics as Capture Probes. ACS Nano, 2009. 3(5): p. 1219-1224.

5. Lin, T.W., et al., Label-free detection of protein-protein interactions using a calmodulin-modified nanowire transistor. Proceedings of the National Academy of Sciences, 2009. 107(3): p. 1047-1052.

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以奈米矽線場效應電晶體觀察糖水解功能

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