具即時性偵測鋅離子之固態尖端式光感測器

Abstract

尖端式鋅離子固態感測器是由兩根平行的光纖緊密嵌入一水凝膠感測膜而形成的。該薄膜由Poly(2-hydroxyethyl methacrylate)(Poly HEMA)水凝膠與具高選擇性的螢光感測分子meso-2,6-Dichlorophenyltripyrrinone (TPN-Cl2)，以0.025％的重量比混合之。一根光纖傳送405nm雷射輸出的激發光，而第二根光纖收集摻雜水凝膠薄膜發出的622 nm螢光。光纖的直徑為370μm（核芯為300μm），其總和大約是感測尖端的直徑。該尖端可對超過鋅離子濃度10-6M有即時性反應，而對10-7M則有一個邊緣的反應信號。將此感測尖端插入牡蠣內部，可以成功地探測到鋅離子，顯示此感測器可操作於複雜的體液中，並能忍受某些機械性外力。為顯示其在醫藥病理上的潛在應用，將此感測膜應用於初期培養的神經元細胞。本研究嘗試首次在缺血、發炎和中毒等受損條件下，在細胞培養基中釋放的鋅離子濃度為10-6〜10-7M。此外，這也與用生化檢驗法偵測的鋅含量有關。此尖端式感測器在活體外或活體內均具有應用於生物醫學上監測之龐大潛力。

A tip-shaped zinc ion solid-state sensor is made by two parallel optical fibers embedded closely in a sensing hydrogel film. The film is made of Poly (2-hydroxyethyl methacrylate) (Poly HEMA) hydrogel mixed with the selective fluorescent probe meso-2,6-Dichlorophenyltripyrrinone (TPN-Cl2) with weight ratio of 0.025 wt%. A 405 nm laser output is sent from one fiber and the 622 nm fluorescence of the doped hydrogel is collected by the second fiber. Each fiber diameter is 370 µm (core is 300 µm), whose sum is roughly the tip diameter. The tip has real-time response for zinc ion concentration over 10-6M, with marginal signal for 10-7M. The tip is inserted inside an oyster and successfully detects the zinc ions, showing that the sensor works in complex body fluid and tolerates certain mechanical stress. To show the potential application for medicine, the sensing film is applied for primary neuronal cultures. We report for the first time Zinc ions release at concentration levels 10-6~10-7M to the medium under stress conditions of ischemia, inflammation, and intoxication. Furthermore, this correlates with the zinc levels detected by biochemical assay. Such sensing tip has great potential for biomedical monitoring ex vivo or in vivo.