矽奈米線場效電晶體生物感測平台

Abstract

生物標記物的即時監測對於疾病管制的改善是極為重要的，特別是早期檢測、快速分析可以有效地減低疾病的發生。為了達到加強疾病監控的目的，則需要一套快速、健全、且不昂貴的檢測技術，用來提供疾病標的物詳盡的分析資訊。本研究將證實，以一簡易且低成本的製程所製備之多晶矽奈米線場效電晶體可用於生物感測。該晶片以相容於現今半導體製程之多晶矽側壁間隔技術(poly-silicon sidewall spacer technique)來製作，且不須昂貴的電子束，便可以達到大量生產的目的。再者，許多文獻已報導多晶矽元件，具有相似單晶矽奈米線場效電晶體易於調控的元件電性。於本研究，功能化之多晶矽奈米線場效電晶體將被證實，可用來超高靈敏偵測神經傳導物質多巴胺，與高致病性禽流感病毒之去氧核醣核酸。當多晶矽奈米線場效電晶體元件表面被修飾高專一性生物辨識分子，可由專一性電性反應量測到10E-15至10E-12莫爾濃度之檢測物。我們更進一步以病毒紅血球凝集素(hemagglutinin)之基因序列來證實，矽奈米線場效電晶體可藉由完全互補的去氧核醣核酸分子，將固定化於奈米線表面之探針分子回復，以達到高專一性檢測、可重複使用的特性。在未來，藉由該元件之超高靈敏度、免標記、即時檢測，可大量商用化生產的潛力，以及易與微流道系統、電路整合的優勢，多晶矽奈米線場效電晶體將有潛力被發展成為可用於專業研究，與定點監測之可攜式生物感測器。

Real-time surveillance of the biomarker is critical for improvements in illness management and is especially important for early detection, rapid intervention, and a possible reduction of the disease occurrence. Enhanced surveillance requires rapid, robust, and inexpensive analytical techniques capable of providing a detailed analysis of biological molecules. A simple and low-cost method to fabricate poly-crystalline silicon nanowire field-effect transistor (poly-SiNW FET) for bio-sensing application was demonstrated. The poly-silicon nanowire (poly-SiNW) channel was fabricated by employing the poly-silicon (poly-Si) sidewall spacer technique, which approach was comparable with current commercial semiconductor process and forsaken expensive electron beam (E-beam) lithography tools for large-scale production. The electronic properties of the poly-SiNW FET in aqueous solution were found to be similar to those of single-crystal SiNW FETs reported in the literature. Functionalized poly-SiNW FETs were used as the biosensors for specific and ultrasensitive detection of neurotransmitter dopamine and high pathogenic avian influenza virus DNA in this study. Specific electric changes were observed for dopamine and DNA sensing when nanowire surface of poly-SiNW FETs was modified with specific recognition capturers and those biological molecules at fM to pM range could be distinguished. We further demonstrated that specific detection, confirmation and recovery of DNA probe on the nanowire surface could be achieved with SiNW-FETs using hemagglutinin DNA as the diagnostic target. With its characteristics (ultrasensitive, label-free, and real-time detection) and advantages (potential for mass commercial production and integration with microfluidic system and circuit), poly-SiNW FET can be developed to become a portable biosensor for field use and point-of-care diagnoses.