fluorophore

https://doi.org/10.1351/goldbook.FT07380
Molecular entity (often organic) that emits fluorescence.
Source:
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 341 (https://doi.org/10.1351/pac200779030293)