pH-stimulus response dye-cucurbituril sensor for amino acids in aqueous solution

摘要

The host-guest inclusion complexes that comprise an inverted cucurbit[7]udl (iQ[7]) and a quinoline derivative, 4-(4-dimethylaminostyryl) quinoline (DSQ) at different pHs were exploited as multiple supramolecular sensors to sense L-alpha-amino adds. DSQ complexation inside iQ[7] at different pHs leads to increased fluorescence and formation of different-colored iQ[7 ]-DSQ complexes. The enhanced fluorescence of DSQ after iQ[7] encapsulation may be attributed to limited dimethylamine rotation and the formation of a twisted internal charge transfer (TICT) state. The DS@i4Q[7] sensors have different affinities for L-alpha-amino adds at different pHs. Therefore, we propose a pH-stimulus response supramolecular sensor for the discrimination of structurally L-alpha-similar amino adds in aqueous solution. (C) 2020 Elsevier B.V. All rights reserved.