FLUORESCENT COMPOUND, FLUORESCENT COMPOUND MIXTURE, FRESHNESS MARKER, FRESHNESS LABEL, AND SENSING SYSTEM

摘要

Disclosed herein is a fluorescent compound represented by the following general formula and having fluorescence characteristics that vary in the presence of a subject substance,; ;wherein R₁ and R₂ each independently represent a carboxyl group, or a substituent containing a carboxyl group, and R₃ and R₄ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, a carboxyl group, or a substituent containing a carboxyl group.