Heterocycle-Modified Quinolines for Fluorescence-Based Protein Kinase Sensing

The present invention generally relates to compositions and methods for determining kinase activity. In some cases, the compositions comprise a triazole heterocycle. In some embodiments, the compositions comprise a quinoline moiety. In one aspect, the present invention is directed to compositions that undergo chelation-enhanced fluorescence (CHEF). In some cases, the compositions may have fluorescence emission spectra with peak maxima greater than 490 nm. The compositions of the present invention can be used, in certain embodiments, to detect phosphorylated substrates and biological processes such as phosphorylation events.