| Abstract: | 我們團隊上次執行的科技部計畫已經成功地實現了利用絲網印刷的石墨烯碳電極開發低成本生物感測器以檢測攝護腺癌生物標誌物EN2蛋白的目標。目前開發的生物感測器能測量濃度在35〜182 nM線性範圍內的EN2濃度，檢測限為38.5 nM。這標誌著使用低成本電極進行EN2檢測的一個里程碑。這一成果已經在2017年的國際期刊上發表。 現在正申請的這個計畫的目的是將低成本生物感測器的檢測能力推向臨床可用範圍，具體而言就是0〜275 nM的檢測範圍和1.25 nM的檢測限。為此，必須對以前計畫中所使用的生物感測器特性進行問題分析。首先，交叉電極的尺寸可能是一個因素。考慮到EN2蛋白的大小只有奈米級，而電極的寬度和間距都是毫米級的。在檢測時固定於電極表面上的EN2蛋白僅影響兩個相對電極之間的電場線的一小部分。因此，減小電極尺寸來達到我們提高靈敏度的目標似乎是可行的。然而，如果我們堅持使用絲網印刷電極來實現低成本的目標，一直縮小印刷尺寸終將面臨越來越大的挑戰。因此，必須發展新的絲網印刷技術或設計先進的電極結構。其次，我們認為上個計畫所使用的電化學方法，即循環伏安法，對電極表面EN2量的變化可能不夠靈敏。因此，我們將對生物感測器的真正的電路模型進行分析，並將進行實驗來幫助和驗證我們建立的電路模型；然後我們將根據所建立的模型而採用適切的電化學方法。其中，從目前的理論看來，電化學阻抗譜（EIS）應該是一個非常合適的方法。 總之，本計畫旨在開發可用於臨床診斷攝護腺癌的低成本、靈敏的生物感測器。這個計畫的成功能夠幫助普及化攝護腺癌的篩檢，促進攝護腺癌的提早發現和及時調控治療，這不僅在學術上有意義，而且造福於潛在的患者、醫療單位、和整個社會。 ;The previous MOST project of our team has successfully attained the goal of detecting EN2 protein, a biomarker of prostate cancer, with a low-cost biosensor based on screen-printed graphene-carbon electrodes. Currently, the developed biosensor can detect EN2 concentration in a linear range from 35 to 182 nM with a detection limit of 38.5 nM. This marked a milestone of EN2 detection with low-cost electrodes. This achievement has been published in a journal paper in 2017. The purpose of this new project proposal is to push the detection capability of the low-cost biosensor to the clinical range. That is a detection range of 0 to 275 nM and a detection limit of 1.25 nM. To this end, problem analysis must be conducted on the biosensor characteristics used in previous project. Firstly, the dimension of the interdigitated electrodes may be a factor. Considering that the size of EN2 protein is only in the nanometer scale while the electrode width and spacing are in the millimeter scale. The EN2 protein, which is immobilized on the electrode surface during detection only affects a small portion of the electrical field line between the two opposite electrodes. Thus, reducing the electrode dimension is a promising direction for our purpose. However, it will pose a big challenge if we stick on using screen-printed electrodes for low cost purpose. Hence, new technique for screen printing or advanced electrode configuration must be invented. Secondly, we consider that the electrochemical method, namely, cyclic voltammetry, may not be sensitive enough to the change of EN2 amount on the electrode surface. Owing to this consideration, the real electrical circuit model of the biosensor will has to be analyzed. Experiments will be conducted to aid and verify our modelling. New electrochemical methods will be adopted on the basis of the modelling result. Among others, Electrochemical Impedance Spectroscopy (EIS) is presumably a suitable method and will be given major attention. In summary, the proposed project is aimed at the development of a low-cost, sensitive biosensor for clinical diagnosis of prostate cancer. The success of this project will definitely result in earlier detection of prostate cancers, which is not only academically meaningful, but also beneficial to potential patients, the hospital, and the whole society. |
