PROBLEM TO BE SOLVED: To provide a fluorescent probe having high light resistance, capable of efficiently detecting a plurality of biological materials, and excellent in safety without adversely affecting organisms.SOLUTION: The fluorescent probe is comprised of a single layer or multilayer of the graphene nanosheet. The fluorescent probe is provided with: a sheet part including at the edge part thereof an armchair type edge face part a graphene structure with a terminal six-membered ring whose only one side jointly owns and bonds to the above armchair type edge face part and a target directivity ligand bonding the sheet part and/or the terminal six-membered ring via a peptide bond (-CO-NH-). Further, the graphene structure may be provided with a nitrogen-containing functional group bonding the carbon atom constituting the sheet part and/or the terminal six-membered ring.
