| 摘要: | 本研究主要利用化學氣相沉積(CVD)的石墨烯轉印至二氧化矽的基板並利用蒸鍍的方式製作電極，將石墨烯當作場效應電晶體(FET)的通道製成的生醫晶片平台，特色在於簡單的製作方法，並且以無標籤式且實時性的感測癌症EBV DNA的濃度，透過狄拉克點的電性訊號變化並轉換成濃度區間的趨勢線，感測當前EBV DNA的濃度，相較於醫學的量測法，例如:磁核共振、電腦斷層掃描或聚合酶連鎖反應，石墨烯場效應電晶體GFET的感測時間短且成本耗費低的優勢都比醫學的方法有潛力，但石墨烯感測器目前需要克服的問題，例如:轉印的殘留物或是感測時的專一性都還是研究中的挑戰。
實驗過程分成上閘極式石墨烯場效應電晶體(TG-GFET)和平面式石墨烯場效應電晶體(PG-GFET)，TG-GFET因為其結構簡單較早被提出討論，而PG-GFET則因為電晶體有較多漏電流的問題，後來解決後被廣泛使用。PG-GFET的閘極材料與通道的距離固定，穩定性較高，且根據文獻模擬的結果，電晶體的通道被平面閘極的電場所影響效果比上閘極的高，所以在實驗中，平面式閘極的靈敏度略高約0.1 V/nM。本實驗的感測器可以達到檢測極限(LoD)於1 pM的濃度，而檢測的線性範圍位於1 pM到10 nM ，其中線性回歸率R2=0.99，表示此感測器可以提供有效的平台用於感測癌症DNA。
;Biosensor research has been addressed as an interesting field recently. Within different kinds of developed biosensing technologies, field-effect transistor (FET) based biosensors stand out due to their attractive features, such as ultra-sensitivity detection, mass production capability, and low- cost manufacturing, have exhibited enhanced performance in the sensing of small biomolecules, heavy metals, pH, protein and DNA. In control experiments with mismatched DNA oligomers, the impact of the mismatch position, and the different number of mismatch oligomers on the DNA hybridization strength was confirmed. experimental results demonstrate that our G-FET high selectivity even in the serum environment.
We compare two different ways fabricated FET and tested, both top-gate FET and plane-gate FET can receive a promising result as DNA biosensor, and plane-gate have some attractive features, such as cost-effective fabrication procedure and easy integration into an IC-chip, beneficial for portable and IoT compatible, due to high field effect to graphene channel, plane-gate have higher sensitivity than top-gate. Our biosensor revealed high selectivity and limit of detection receive 1 pM, the detection linear range at 1 pM to 10 nM (R2=0.99) and sensitivity can reach 0.03 V/nM, shows high reliability and characteristic. |
