發展自動微型的分析方法應用於質譜及光學偵測

Abstract

各式各樣的現代科技促進了化學分析的發展，像是能夠將自動化和微小化用於傳統的化學方法。因此這裡我們建立兩套分析系統應用於分析化學。 在第一個研究中，我們建造一個結合機械手臂和電子控制元件的裝置，並應用於質譜分析上之樣品前處理及遞送樣品。此裝置能夠鑑定樣品、加試劑、混合樣品，並遞送樣品至質譜前之離子源，整個分析程序是藉由C語言來完成。為了能夠精確的控制手臂的位置，我們利用多種不同種類的低成本之感測器來幫忙導引機械手臂；我們同時也利用這套系統來監測穀胱甘肽的氧化過程。 在第二個研究中，我們利用油水互不相溶的系統來進行化學反應，利用微量吸管滴入微升體積之水滴於油相，再等待它們自發的混合；此研究中，我們利用智慧型手機當作偵測器進行一系列的反應，舉例來說：比色法、螢光法、化學發光法，此三個方法中，我們分別利用過錳酸鉀氧化還原反應 (比色法)、胰蛋白酶酵素分解螢光素標記之酪蛋白(螢光法)，及魯米諾和次氯酸鈉之氧化反應(化學發光)來證實此分析系統的應用。此分析系統用於不同方法之偵測極限分別為：1.19毫莫耳濃度的過錳酸鉀、1.37微莫耳的螢光素，及112奈莫耳濃度的次氯酸鈉。因此，我們的系統既可使用少量的樣品進行分析，而且系統本身非常之低成本。總結來說，利用一些簡易的器材及低成本的電子零件，是有機會打造自動化及微小化的分析方法並應用於質譜法及光學偵測。

Various modern technologies facilitate chemical analysis. They often enable automation and miniaturization of conventional chemical assays. We have developed two analytical methods which address some of the persisting challenges of analytical chemistry. In the first study, we constructed a system incorporating a robotic arm and electronic control units to pre-treat and deliver samples for mass spectrometric analysis. It identifies the sample, adds a reagent, incubates the reactants, and transfers the reaction mixture to the ion source of an ion-trap mass spectrometer. The whole analysis sequence has been programmed in C language. In order to enable precise control of movements of the robotic arm, the momentary position of the arm was verified based on the signals received from a number of sensors. We applied this automated device in the monitoring of glutathione oxidation in real time. The device has been made of low-cost materials. Hence, it can readily be replicated. In the second study, we developed an analytical method that takes advantage of the fusion of aqueous droplets in a non-polar (oil) matrix to trigger chemical reactions. Microliter or sub-microliter droplets are pipetted nearby into the oil, and they spontaneously fuse initiating the reaction. Optical detection of the reaction product is conducted using the smartphone built-in camera. Using LED light source, colorimetric, spectrophotometric and fluorimetric detection was possible. Chemiluminescence detection was achieved in the absence of light source. The LODs obtained with colorimetric, fluorimetric and chemiluminescence detection are 1.19 mM (potassium permanganate), 1.37 μM (fluorescein), and 112 nM (sodium hypochlorite), respectively. The proposed method enables analysis of low-volume samples a low cost. It can be applied to chemical reactions which generate chromophoric, fluorogenic or chemiluminescent products or intermediates. To conclude, using a range of widely available inexpensive electronic modules, and other pieces of equipment, it is possible to develop automated and miniaturized analytical assays with mass spectrometric or optical detection.