5-Aryl-2,2′-bipyridines as tunable fluorophores

Readily available 5-aryl-2,2′-bipyridines and their derivatives are a unique family of fine-tunable chromophores, where changes in the substitution patterns, solvation and coordination are translated into dramatic spectral changes. They exhibit sensitive and selective response to zinc ions with dramatic increases in emission intensity or significant red-shifts of emission maxima.