The disclosure relates to a fluorescence based assay for the detection of alpha, beta-dicarbonyl containing compounds, for example alpha-oxoaldehyde compounds such as glyoxal, methylglyoxal, hydroxypyruvaldehyde, erythrosone, 3-deoxyerythrosone, ribosone, 3- deoxyribosone, glucosone, 3-deoxyglucosone and stereoisomers thereof and butan-2,3- dione that uses a fluorogenic probe which is stable under ambient conditions. The fluorogenic probes comprise a 1,2-diaminophenyl moiety. The diaminophenyl probes yield a 20-fold increase in quantum yield when they are a derivative of fluorescein (DAF), rhodamine (DAR), BODIPY or cyanine. The assay is preferably carried out at pH 4-8. Corresponding screening methods for modulators of alpha, beta-dicarbonyl compound concentrations are also disclosed.