A bifunctional acridine-based fluorescent sensor: ratiometric sensing of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mrow><mml:msup><mml:mrow><mml:msub><mml:mtext>H</mml:mtext><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mtext>PO</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:mrow><mml:mo>−</mml:mo></mml:msup></mml:mrow></mml:math> and obvious fluorescence quenching towards <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"><mml:mrow><mml:msup><mml:mrow><mml:msub><mml:mrow><mml:mtext>HSO</mml:mtext></mml:mrow><mml:mn>4</mml:mn></mml:msub></mml:mrow><mml:mo>−</mml:mo></mml:msup></mml:mrow></mml:math> through a synergistic binding effect of benzimidazolium and urea moieties
作者:Dawei Zhang、Xiaozhi Jiang、Zhiyun Dong、Haiqiang Yang、Alexandre Martinez、Guohua Gao
DOI:10.1016/j.tet.2013.09.083
日期:2013.12
Three tweezer-like fluorescent sensors 1-3 based on acridine fluorophore were designed and synthesized. Anion binding properties of sensors 1-3 were studied by fluorescence, UV-vis, H-1 NMR, and FIRMS. Results showed that the sensor 1, which bears both benzimidazolium and urea groups as binding sites exhibited better anion sensing performance compared with sensors 2 and 3 containing only one kind of binding sites. Especially, it could be used as a dual-responsive selective fluorescent sensor for both H2PO4- and HSO4- via fluorescent bathochromic-shift and fluorescence quenching, respectively. The unique selectivity of sensor 1 towards H2PO4- and HSO4- could be attributed to the synergistic binding effect of benzimidazolium and urea moieties. In addition, the additional hydrogen bond between -OH in H2PO4-/HSO4- and the N on acridine of sensor 1 also played an important role in improving its anion binding affinities. (C) 2013 Elsevier Ltd. All rights reserved.