| 摘要: | 我們開發液晶液滴用於即時檢測水溶液中金屬離子，在我們的研究中分為兩部分，在第一部分我們摻雜4''-(octyloxy)-[1, 1''-biphenyl]-4-carboxylic (8OBCA) 在5CB中，利用8OBCA作為兩性分子穩定液晶液滴。當加入含有金屬離子的溶液時，其組態會從radial轉變為bipolar，該液晶液滴可以用於檢測鎂、鈣、鎘、錳、鈷、鉛離子。在第二部分我們將摻雜物8OBCA改為對汞離子具有專一性的配基5-(pyridine-4-yl)-2-(5-(pyridin-4-yl)- thiophen-2-yl)thiazole (ZT)，在含有汞的溶液中ZT會與汞離子形成錯合物而導致組態從radial轉變為bipolar，藉由觀察此現象可以對汞進行專一性檢測且其偵測極限為25 μM，該系統也能在真實水樣中檢測汞離子。由於液晶液滴的變化可藉由肉眼判斷，因此該系統可作為一般民眾檢測水溶液中汞離子的方法。
We report the liquid crystal (LC) droplets which are able to detect the metal ions in water in real-time. We divide into two parts in our research, in first part, we doped nematic LC (5CB) with 4''-(octyloxy)-[1, 1''-biphenyl]-4-carboxylic acid (8OBCA) which acts as the amphiphilic molecules decorated at LC/aqueous interface to stabilize the droplets. When the carboxylic groups on the surface of LC droplets interacted with the metal ions in water, the configurational transition of LCs from radial to bipolar was observed. Our results showed that the LC droplets are able to detect a series of metal ions including Mg2+, Ca2+, Cd2+, Mn2+, Co2+, and Pb2+. In second part, We changed dopant into a mercuric ion-selective ligand, 5-(pyridine-4-yl)-2-(5-(pyridin-4-yl)- thiophen-2-yl)thiazole (ZT). When the LC droplets were dispensed in the solution containing Hg2+, the formation of Hg2+/ZT complexes lead to a distinct radial-to-bipolar configurational transition of LC droplets. By using this mechanism, the LOD of Hg2+ can be detected is 25 μM, and it has high selectivity for detecting Hg2+. Besides, we also demonstrated that this system can be used to detect Hg2+ in tap water and pond water. Because the signals of LC droplets can be differentiated through the naked-eye under ambient light, it provides a simple approach for normal users to be aware of the presence of Hg2+ at localized aqueous environment. |
