Abstract:
Ethyl(hydroxyethyl)cellulose (EHEC) and a silica-based xerogel (SBX) were functionalized with a (18-crown-6)-styrylpyridine precursor (1) to obtain the modified polymers EHEC-1 and SBX-1, respectively. Films were obtained and the resulting materials were used as fluorogenic devices for the detection of Hg2+ in water. The films produced from EHEC-1 showed high water retention, making it difficult to apply as a reusable optical chemosensor. Since SBXs are recognized in the literature for their hydrophobicity, a hybrid film composed of EHEC and SBX-1 which did not show water retention was produced and characterized. This system showed rapid response time, outstanding selectivity compared to several other studied metal ions, and sensitivity for the detection of Hg2+ in water. The detection limit for this material using fluorescence technique was 2 ppb (∼10-8 mol L-1). The reversibility of the complex formed between EHEC-SBX-1 film and Hg2+ was demonstrated by the addition of cysteine to the medium. The result obtained also allowed the assembly of INHIBIT and IMPLICATION molecular logic gates, using Hg2+ and cysteine as inputs. The results described in this article have important significance in the development of novel reversible fluorogenic chemosensors and adsorbent materials for the effective removal of Hg2+ ions.
摘要:
将乙基(羟乙基)纤维素(EHEC)和基于二氧化硅的干凝胶(SBX)用(18-冠-6)-苯乙烯基吡啶前体(1)官能化,以分别获得改性聚合物EHEC-1和SBX-1。获得膜,并将所得材料用作荧光装置,用于检测水中的Hg2+。由EHEC-1生产的薄膜显示出高的保水性,使其难以作为可重复使用的光学化学传感器应用。由于SBX的疏水性在文献中得到认可,制备并表征由EHEC和SBX-1组成的不显示保水性的杂化膜。该系统显示出快速的响应时间,与其他几种研究的金属离子相比,具有出色的选择性,和灵敏度检测水中的Hg2+。使用荧光技术对该材料的检出限为2ppb(〜10-8molL-1)。通过向培养基中添加半胱氨酸证明了EHEC-SBX-1膜与Hg2之间形成的复合物的可逆性。获得的结果还允许组装抑制和暗示分子逻辑门,使用Hg2+和半胱氨酸作为输入。本文描述的结果对开发用于有效去除Hg2离子的新型可逆荧光化学传感器和吸附材料具有重要意义。