微型核糖核酸 (miRNA)被認為是疾病和癌症潛在的生物標記物 (Biomarker),因此開發了許多相應的生物傳感器作為替代診斷工具。然而胰臟癌 (Pancreatic cancer)是沉默的殺手,因為它在早期階段不易被發現,因此,開發可靠的生物感測平台具有重要意義。我們建構了雙擴增生物傳感平台,以檢測與胰臟癌相關之miR-196b,我們設計一種聚合酶輔助的鏈置換反應與模板引導類似酵素功用之富含鳥糞嘌呤的產物形成(DNAzyme),將目標物miR-196b 透過聚多巴胺奈米金複合材料修飾之網版印刷電極表面轉化為電化學訊號,藉由氯化血紅素 (Hemin)與DNAzyme 結合,催化3,3',5,5'-四甲基聯苯胺使其氧化,產生的電化學訊號用於目標物miR-196 之濃度校正。我們成功建立針對目標物miR-196b 之生物傳感器,具有極佳的偵測極限 (0.23 pM)及區分不同miRNA之能力。我們甚至添加miR-196b 至真實血清樣品中獲得了105 %的回收率,這表明該生物傳感器在真實樣品檢測中的多功能性。
MicroRNAs have been considered to be potential biomarkers for diseases and cancers, so a number of biosensors are accordingly developed as alternative diagnostic tools. However, pancreatic cancer, for example, is a silent killer because it is not easily detected in the early stage. In response, it is of importance to develop a reliable biosensing platform for the detection of pancreatic cancer. A dual-amplification biosensing platform is constructed to detect pancreatic cancer-associated miR-196b. A polymerase-assisted strand displacement reaction and template-guided formation of enzyme-mimicking, guanine-rich-containing products (DNAzyme), are designed to translate the biosensing process of target miR-196b into an electrochemical signal on a PDA/Au composite-modified screen-printed electrode. The electrochemical signal, generated by the oxidation of 3,3',5,5'-Tetramethylbenzidine (TMB) via a hemin-intercalating DNAzyme catalytic process, is used to calibrate the concentration of target miR-196b. An excellent detection limit of 0.23 PM and capability of discriminating different miRNAs show the successful establishment of the biosensing platform for target miR-196b. We even challenged the biosensing platform with miR-19b-spiked real serum samples, and a recovery rate of 105% is obtained, suggesting the versatility of the biosensor in real sample detection.