超高靈敏度的羧基改性氧化石墨烯之生醫感測於表面電漿子共振晶片之研發

Abstract

本論文使用以羧基改性氧化石墨烯為基材的表面電漿子共振感測晶片檢測牛血清蛋白以及糖類抗原19-9。首先使用牛血清蛋白比較羧基改性氧化石墨烯生醫晶片、氧化石墨烯生醫晶片、傳統生醫晶片的靈敏度。再由靈敏度最高的羧基改性氧化石墨烯生醫晶片檢測糖類抗原19-9。

本論文也探討羧基改性氧化石墨烯、氧化石墨烯、石墨烯三種材料的導電性和單位折射率角位移靈敏度(S_RI)以及生物分子的吸附效率(E)比較。羧基改性氧化石墨烯擁有比氧化石墨烯更高的導電性，因為羧基能增加碳鏈的可饒性，且讓電荷載體更容易地沿著碳鏈移動。而導電性的提昇能增加表面電漿子極化的傳播常數，其與S_RI是正比的關係。表面電漿子共振系統被用來驗證羧基改性氧化石墨烯的S_RI度比氧化石墨烯更高。多功能電漿量測系統用來觀察羧基改性氧化石墨烯在640 mn-700 nm波長內表面電漿子共振角的特性。而穿透光譜系統以及掃描式電子顯微鏡則是被用來觀察羧基改性氧化石墨烯鍵結在晶片的特性。

在實驗中證明了以羧基改性氧化石墨烯為基材的表面電漿子共振生物晶片於檢測牛血清蛋白時擁有超高的靈敏度和超低的檢測極限。0.275 mg/ml的羧基改性氧化石墨烯生醫晶片靈敏度比2 mg/ml的氧化石墨烯生醫晶片提升了2.1倍。除此之外，羧基改性氧化石墨烯生醫晶片在檢測牛血清蛋白抗體時最低檢測極可達10 fg/ml，明顯優於傳統生醫晶片。最後使用羧基改性氧化石墨烯進行糖類抗原19-9免疫反應的檢測。文獻指出有79%的胰腺癌病患體內糖類抗原19-9的含量在37 unit/ml以上。實驗結果發現以羧基改性氧化石墨烯為基材的表面電漿子共振生物晶片最低的抗原檢測極限可達10 unit/ml。

基於本論文的實驗結果，以羧基改性氧化石墨烯為基材的表面電漿子共振生物晶片未來可以被使用在臨床診斷，廣泛應用於製藥行業、農業與環境檢測，大幅改善國人的健康品質。

In this paper we proved that carboxyl-functionalized graphene oxide (GO-COOH) was used to detect pancreatic cancer indicator protein 19-9 with surface plasmon resonance (SPR) (Carbohydrate Antigen, CA19-9). We compare the sensitivity of GO-COOH biosensor、GO biosensor and traditional biosensor with bovine serum albumin. Next to detected CA19-9 by the highest sensitivity of GO-COOH biosensor.

GO-COOH, graphene oxide (GO) and graphene were discussed with conductivity、SPR angular displacement sensitivity (S_RI) and adsorption efficiency of biomolecules. GO-COOH has better conductivity than GO because the carboxyl group is more flexible with carbon chain than other oxygen-containing functional groups and allows the charge carrier to move more easily along the carbon chain. The enhancement of conductivity increases the propagation constant of the surface plasma polarization, which is proportional to S_RI, and uses the SPR system to verify that GO-COOH is better than GO. Multifunctional plasmonic system (MPS) was been used to observe the characteristics of GO-COOH at the SPR angle of 640 mn-700 nm. The penetrating spectroscopy system and the Scanning electron microscope (SEM) were used to observe the properties of the GO-COOH bond on the chip.

Experiment of SPR system is proved that GO-COOH-based surface plasmon resonance biochip has high sensitivity and low detection limit when detecting Anti-Bovine Albumin antibody (anti-BSA). 0.275 mg/ml GO-COOH biochip was 2.1 times better than the 2 mg/ml GO chip. In addition, the limit of detection of GO-COOH biochip low to 10 fg/ml in the detection of anti-BSA, significantly better than traditional biochip. Finally, the SPR system was used to detect the CA19-9 immune response. Previous literature indicates that 79% of patients with pancreatic cancer contains CA19-9 above 37 units/ml. The results show that the lowest antigen detection limit of GO-COOH as the biomaterial is 10 unit/ml.

Based on the experimental results of this paper, the surface plasmon resonance biochip with GO-COOH as the biomaterial can be used in clinical diagnosis and widely used in the pharmaceutical industry, agriculture and environmental testing, and greatly improve the health quality of people.