敗血症是一種可能危及生命的疾病，定義為感染所引發的全身性嚴重發炎反應，細菌感染是血液感染的最常見原因，然而也可能由病毒和真菌感染引起。其所引起的發炎反應可能導致組織損傷，器官衰竭，休克甚至死亡，因此敗血症在臨床上是一種可能會危及性命的嚴重併發症，致死率可能高達七成以上。最標準的細菌檢測方式為利用培養基進行細菌增殖，再利用一系列生化反應，例如微生物發酵、特定受質的利用、還原與降解等特性來鑑定微生物種類，或是利用聚合酵素連鎖反應 (Polymerase Chain Reaction，PCR)，質譜鑑定(Mass Spectrometry，MS)等大型機台進行判讀，這些方法精準度高，但至少需耗費一天以上作增殖反應，若遇上培養困難、生長緩慢或是無適當培養基的菌種再更為耗時。
為了克服上述問題，本研究提出了兩種微流體介電泳晶片，基於介電泳力(Dielecteophoresis, DEP)與電滲流(Electroosmotic flow)分離與聚集大腸桿菌(Escherichia coli, E. coli)，並利用SERS指紋識別技術檢測微流道中的細菌。第一種為分離晶片，藉由指叉型交錯之金屬電極結構，產生不均勻電場之介電泳力分離出大腸桿菌，並利用自摻雜磺化聚苯胺(self-doped sulfonated polyaniline, SPANI)作為塗層材料整合於Au電極上，改善表面非特異性吸附造成的沾黏問題；第二種為聚集晶片，藉由上與下之銦錫氧化物玻璃(ITO-coated glass)作為電極，產生之介電泳力與電滲流聚集大腸桿菌。最後，於待測溶液中加入能夠增加拉曼訊號之碘化奈米銀粒子(AgINMs)，並應用聚集晶片濃縮待測物，目前已可辨識出大腸桿菌之SERS訊號。

Sepsis is a potentially life-threatening condition and defined as the systemic inflammatory response syndrome (SIRS) caused by infections. Bacterial infections are the most common cause of bloodstream infection; however, they can also be caused by viral and fungal infections. The inflammatory reaction caused by sepsis may lead to tissue damage, organ failure, shock, or even death. Therefore, sepsis is a serious complications that can endanger lives, and the mortality rate might reach up to 70%. The most standard method of bacterial detection is to use the culture medium for bacterial proliferation, and then use a series of biochemical reactions, such as microbial fermentation, specific substrate utilization, reduction and degradation, to identify microbial species, or to use large-scale machines such as polymerase chain reaction (PCR) or mass spectrometry (MS) for interpretation. These methods are highly accurate, but required at least one day for proliferative reactions. It is more time consuming to encounter strains that are difficult to grow, slow to grow, or have no suitable medium.
To overcome aforementioned problems, this study proposed two different microfluidic dielectrophoresis devices to separate and concentrate Escherichia coli (E. coli), and utilize SERS fingerprint identification to detect bacteria in microfluidic chips. In terms of separation, E. coli are separated by DEP force generated from the gold interdigitated electrodes. And self-doped sulfonated polyaniline (SPANI) is used as a coating material on the Au electrodes to improve the fouling of electrodes caused by non-specific adsorption; In terms of concentration, E. coli are collected by DEP and electroosmotic forces generated from the top and bottom indium tin oxide (ITO)-coated glasses. To identify the bacteria, the AgINMs which can increase the Raman signal are mixed with the solution to be detected and injected into concentration chips, and the SERS signal of E. coli could be recognized after concentration.

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