Dansyl–antipyrine dyad as a fluorescent sensor for Cu2+ and F−: sequential XNOR logic operation

Abstract

Dansyl and antipyrine based hybrid molecular architectures were synthesized and their photophysical behavior towards various cations and anions was investigated. The dyad 1 was used for selective estimation of Cu²⁺ ions as compared to other metal ions and the binding event was indicated through formation of a new absorption band at 465 nm and a decrease in fluorescence intensity at 528 nm. The dyad 1 showed ratiometric fluorescence behavior towards fluoride ions through hydrogen bonding interactions and restricted the photoinduced electron transfer from dansyl to antipyrine moiety to release its fluorescence at 428 nm. The chemical inputs of Cu²⁺ and F⁻ ions to dyad 1 mimicked a sequence dependent operation of an exclusive-NOR (XNOR) logic gate.