We have developed two efficient strategies to incorporate privileged cyanobenzene organic photocatalysts into functional peptides. The first approach involved a photo-mediated, Cterminal selective decarboxylative arylation, enabling the attachment of various peptides to diverse CzBN cores. The second approach leveraged a cysteine-selective SNAr reaction with 3CzFIPN, which improved reaction efficiency and avoided the issue of diastereoisomer formation at peptide C-termini. The resulting peptide-CzBN and CzIPN conjugates exhibited strong delayed fluorescence, broad redox potential windows, and high excited state energies. We demonstrated the potential of using these conjugates as photocatalyst for biomolecule functionalization through a photo-mediated decarboxylative alkynylation in organic solvents and a thiol-ene reaction in aqueous media. Additionally, the conjugated promoted aryl azide excitation, enabling protein labeling both in vitro and at the cellular level. Using a peptidic ligand of integrin αvβ3, proximity-labeling of the protein and its interactome became possible via aryl azide excitation. We believe these conjugates will open new avenues for the development of novel photo-mediated biomolecule functionalizations in biological contexts. X.L. performed the experiments under the supervision of J.W.. W.C. conducted the western blot and cell experiments under the supervision of B.F.. A.C. conducted the photophysical studies of peptide-CzPN conjugates, including data analysis and draft preparation. X.L and J.W. contributed to the overall design of the study, data analysis and writing of the manuscript.