Fig. 5. ¹⁹F NMR spectra of 0.3 mM 5-F-Trp-b′x with increasing concentration of Δ-somatostatin peptide (Δ-som). ¹⁹F NMR spectra of 48 h ‘aged’ 5-F-trp-b′x shows ¹⁹F resonances reporting on ‘capped’ and ‘uncapped’ x-linker and 5-fluoroindole are also shown.