The invention relates to a fluorescent tracer (Tf2) comprising: - a RAFT frame (1) comprising the residues: -glycine-proline-lysine-alanine-lysine-glycine-proline-lysine-lysine-lysine and having a mean plane (Pm) defining an upper face (Fs) having four lysine residues (Kc, Ke, Kh, Kj) and a lower face (Fi) having a lysine residue (Ki) - four identical targeting molecules (3) comprising the amino acids: arginine - glycine - aspartic acid - phenylalanine - lysine (RGDfK), each of the molecules (3) being attached to a lysine residue (Kc, Ke, Kh, Kj) different than the upper first face (Fs) by an oxime bond, and - a fluorophore (4) S0456 attached to the lower face (Fi) of the mean plane (Pm) via a spacer arm (8) connecting the central carbon of the sequence of double bonds of the fluorophore (4) and the lysine amino acid (Ki) of the lower face (Fi) of the decapeptide (1) via an amide bond, wherein the spacer arm is 5-(4-hydroxyphenyl)pentanoic acid.
