A calixpyridinium-pyranine complex as a selective anion sensing assembly via the indicator displacement strategy

The recently reported calixpyridinium tetracation is shown to be very well-suited for anion sensing via the indicator displacement strategy. A very strong binding interaction between the positively charged receptor and the fluorescent pH indicator pyranine (8-hydroxy-1,3,6-pyrenetrisulfonate) requires an anionic guest of comparable negative charge for effective indicator displacement. Thus, selective and sensitive signalling of ATP is achieved in aqueous solutions. (C) 2004 Elsevier Ltd. All rights reserved.