以矽奈米線場效電晶體作為肝細胞癌生物檢測器

Abstract

肝細胞癌(Hepatocellular carcinoma)是肝癌中最常見的一種，造成原因有病毒性肝炎(Viral hepatitis)、酒精性肝炎(Alcoholic hepatitis)、肝硬化(Cirrhosis)等等。肝細胞癌是台灣癌症中致死率最高的，主要原因為不容易早期發現，等到發現時常常已經到了癌症末期。因此研發早期偵測肝細胞癌的方法，可以降低病人的死亡率。肝細胞癌有兩種生物標記(Biomarker)，甲種胎兒蛋白(Alpha-fetoprotein)與 岩藻糖水解酶(Alpha-L-fucosidase)。先前研究發現，甲種胎兒蛋白與岩藻糖水解酶在肝細胞癌患者的血清中濃度與正常人不同。所以檢測甲種胎兒蛋白與岩藻糖水解酶在血清中濃度，可以於早期判斷患者是否罹患肝細胞癌。本論文使用矽奈米線場效電晶體(Silicon nanowire field-effect transistors)來偵測岩藻糖水解酶與Fuconojirimycin衍生物之間的結合常數，並且利用分析方法來得到岩藻糖水解酶在血清中濃度。 矽奈米線場效電晶體具有即時回應(Real-time)、非標定偵測(Label-free detection)、高靈敏度(High sensitivity)與專一選擇性(Selectivity)等優點，在生醫檢測上受到相當大的重視。Fuconojirimycin衍生物是岩藻糖水解酶的抑制劑(Inhibitor)之一，可以與岩藻糖水解酶緊密結合，因此我們將Fuconojirimycin衍生物修飾在矽奈米線場效電晶體表面。前半部分實驗我們將含有不同濃度的岩藻糖水解酶溶液流過矽奈米線場效電晶體表面，根據不同濃度下電訊號變化量得到岩藻糖水解酶與Fuconojirimycin衍生物的結合常數(Binding constant)。後半部分實驗我們將病人血清稀釋，接著利用標準添加法(Standard addition method)加入定量的岩藻糖水解酶並進行偵測，最後從檢量線(Fitting curve)推算出病人血清中岩藻糖水解酶的濃度。跟傳統判斷蛋白質濃度方法，例如螢光法相較，矽奈米線場效電晶體縮短了偵測時間，且不需純化分離岩藻糖水解酶。我們的研究給予了早期檢測肝細胞癌一個可靠且快速的新方法。

Hepatocellular carcinoma (HCC), one of the most common malignant neoplasms, is closely associated with cirrhosis, but so far with very poor prognosis. Recent clinical studies revealed that alpha-fetoprotein (AFP) and alpha-L-fucosidase (AFU) enzyme play important roles in the early HCC diagnosis, where the simultaneous determination of both activities can drastically increase diagnostic accuracy and sensitivity. In this study, we applied silicon nanowire field-effect transistors (SiNW-FETs) as a sensitive biosensor for the early HCC diagnosis to detect AFU and AFP. While AFU can be probed by a fuconojirimycin derivative (i.e., 1-aminomethyl-FNJ, the AFU inhibitor), AFP is detected with AFP antibody. To detect AFU, we modified FNJ as a receptor on the surface of a SiNW-FET. Taking advantage of the real-time, label-free, high sensitivity and selectivity of SiNW-FET, we determined the binding affinity between AFU and FNJ and measured the concentrations of AFU in serum. We can also determined concentration of AFU in human serum by using an analytical method. In previous researches, HCC patients have abnormal concentration of AFU; therefore SiNW-FET can be used to estimate if a patient has HCC. Compare to traditional methods, such as fluorescence method, SiNW-FET shorten the diagnosis time and has no need to purify AFU. Our results give a great choice in early-stage diagnosis of HCC.