A N-(2-hydroxyethyl)piperazine dangled 2,5-diphenyl-1,3,4-oxadiazole-based fluorescent sensor for selective relay recognition of Cu 2+ and sulfide in water

A new 2,5-diphenyl-1,3,4-oxadiazole-based derivative (L) was synthesized and applied as a highly selective and sensitive fluorescent sensor for relay recognition of Cu and S in water (Tris-HCl 10 mM, pH = 7.0) solution. L exhibits an excellent selectivity to Cu over other examined metal ions with a prominent fluorescence 'turn-off' at 392 nm. L interacts with Cu through a 1:2 binding stoichiometry with a detection limit of 4.8 × 10 M. The on-site formed L-2Cu complex exhibits excellent selectivity to S with a fluorescence 'off-on' response via a Cu displacement approach. Copyright © 2016 John Wiley & Sons, Ltd.