A polymeric nanoparticle comprising: - a hydrophobic polymer, said chains bearing at least one motif of formula, wherein: - A represents a spacer chosen from: -(CH 2) m -, -(CH 2) p NH-CO(CH 2) q -, -(CH 2) p CO-NH(CH 2) q -, -(CH 2) p O(CH 2) q -, -(CH 2) p NH(CH 2) q O-, -(CH 2) m CO-, -CO(CH 2) m -, each of m, p and q represent independently from each other an integer chosen from 0 to 8, preferably an integer chosen from 0 to 5, more preferably an integer chosen from 0 to 3, - D represents a group chosen from: - wherein R' represents a hydrogen, a halogen, a (C1-C8)alkyl, - a cyclo(C3-C7)alkyl eventually monosubstituted, a monocyclic non-aromatic heterocyclic group eventually monosubstituted, or a monocyclic aromatic group eventually monosubstituted, - E represents (̵Y-NR a)̵, where R a is H or an (C1-C8)alkyl, - X, Y, Z are identical or different and each represent independently of the other a spacer chosen from -(CH 2) r -, -(CH 2 -CH 2 -O) r -, -(CH 2 -CH 2 -NH) r -, -(CH 2) s NH-CO(CH 2) t -, -(CH 2) s CO-NH(CH 2) t -, wherein r, s and t represent independently from each other an integer chosen from 0 to 8, preferably an integer chosen from 0 to 3, - n represents an integer chosen from 1 to 10, in particular 1 to 3 when D represents E can be absent; said motif of formula being bound to a carboxyl group of the polymer and being situated on the surface of the nanoparticle, optionally, said polymeric nanoparticle comprising luminescent dyes. - a hydrophobic polymer, said chains bearing at least one motif of formula, wherein: - A represents a spacer chosen from: -(CH 2) m -, -(CH 2) p NH-CO(CH 2) q -, -(CH 2) p CO-NH(CH 2) q -, -(CH 2) p O(CH 2) q -, -(CH 2) p NH(CH 2) q O-, -(CH 2) m CO-, -CO(CH 2) m -, each of m, p and q represent independently from each other an integer chosen from 0 to 8, preferably an integer chosen from 0 to 5, more preferably an integer chosen from 0 to 3, - D represents a group chosen from: - wherein R' represents a hydrogen, a halogen, a (C1-C8)alkyl, - a cyclo(C3-C7)alkyl eventually monosubstituted, a monocyclic non-aromatic heterocyclic group eventually monosubstituted, or a monocyclic aromatic group eventually monosubstituted, - E represents (̵Y-NR a)̵, where R a is H or an (C1-C8)alkyl, - X, Y, Z are identical or different and each represent independently of the other a spacer chosen from -(CH 2) r -, -(CH 2 -CH 2 -O) r -, -(CH 2 -CH 2 -NH) r -, -(CH 2) s NH-CO(CH 2) t -, -(CH 2) s CO-NH(CH 2) t -, wherein r, s and t represent independently from each other an integer chosen from 0 to 8, preferably an integer chosen from 0 to 3, - n represents an integer chosen from 1 to 10, in particular 1 to 3 - A represents a spacer chosen from: -(CH 2) m -, -(CH 2) p NH-CO(CH 2) q -, -(CH 2) p CO-NH(CH 2) q -, -(CH 2) p O(CH 2) q -, -(CH 2) p NH(CH 2) q O-, -(CH 2) m CO-, -CO(CH 2) m -, each of m, p and q represent independently from each other an integer chosen from 0 to 8, preferably an integer chosen from 0 to 5, more preferably an integer chosen from 0 to 3, - D represents a group chosen from: - wherein R' represents a hydrogen, a halogen, a (C1-C8)alkyl, - a cyclo(C3-C7)alkyl eventually monosubstituted, a monocyclic non-aromatic heterocyclic group eventually monosubstituted, or a monocyclic aromatic group eventually monosubstituted, - wherein R' represents a hydrogen, a halogen, a (C1-C8)alkyl, - a cyclo(C3-C7)alkyl eventually monosubstituted, a monocyclic non-aromatic heterocyclic group eventually monosubstituted, or a monocyclic aromatic group eventually monosubstituted, - E represents (̵Y-NR a)̵, where R a is H or an (C1-C8)alkyl, - X, Y, Z are identical or different and each represent independently of the other a spacer chosen from -(CH 2) r -, -(CH 2 -CH 2 -O) r -, -(CH 2 -CH 2 -NH) r -, -(CH 2) s NH-CO(CH 2) t -, -(CH 2) s CO-NH(CH 2) t -, wherein r, s and t represent independently from each other an integer chosen from 0 to 8, preferably an integer chosen from 0 to 3, - n represents an integer chosen from 1 to 10, in particular 1 to 3 when D represents E can be absent; said motif of formula being bound to a carboxyl group of the polymer and being situated on the surface of the nanoparticle, optionally, said polymeric nanoparticle comprising luminescent dyes.