液晶感測系統 (liquid crystal based sensor system) 是利用液晶在排列狀態的不同在偏光下可以得到不同的訊號，是一種便宜、操作簡單等特性的檢測系統，能夠讓使用者馬上判斷出實驗結果。 我們的研究分為兩部分，第一部分為金屬離子的檢測，我們將能夠與金屬離子配位的參雜分子與液晶混和，當溶液中含有金屬離子時，錯合物產生於液晶/水溶液界面，使液晶方向改變，而液晶的光學訊號會由暗轉為亮。 第二部分為酸鹼度的檢測，我們將能不同pKa參雜分子與液晶混和，當酸鹼度發生變化時，參雜分子解離或質子化於液晶/水溶液界面，造成液晶方向改變，而得到不同的液晶的光學訊號。 Recent studies on design liquid crystal based sensor which was focused on liquid crystal/aqueous interface property to control liquid crystal arrangement. In detection of metal ions system, This system was composed of five individual detection wells in which the nematic LC 4-cyano-4’-pentyl biphenyl (5CB) was doped with a metal selective ligand including. When the solution containing metal ions was injected into the well, the formation of metal complex disrupted the orientation of LCs, which led to a transition of the image. Multiplex screening of the metal ions was achieved through the specific binding of ligands to various metal ions; while the quantitative determination was achieved by applying the ligands with different sensitivities toward the same metal ion. This system can be readily understood through human naked-eye under ambient light, it provides a simple approach for fast-screening water quality with less limitations. In pH determination system, 4-cyano-4’-pentyl biphenyl (5CB) was doped with pH sensitive probe, respectively. When the system was injected with the different pH solution, the dissociation of charged dopants would reorientate LCs and lead to transition of the image. The results of the LC based sensor have defined the range of the pH from pH 7 to pH 8 by used different dopants. In addition, the system used different concentration dopant have defined the range of the pH from pH 6.2 to pH 7. The results show the real time and accurate measurements of the pH range specifically and with great stability.
