Monitoring Peptide Coacervate Reactions

Microplate reader measurements: To a 200 μL peptide coacervate dispersion (5 mg mL⁻¹), 0.5 μL [Cp*Ru(cod)Cl] (Cp* = pentamethylcyclopentadienyl, cod = 1,5-cyclooctadiene, abbreviated as Ru, 2 mg mL⁻¹ in DMSO) was added by pipetting. After equilibration for 2 min, 0.5 μL caged resorufin (4 mg mL⁻¹ in DMSO) was added to the mixture. The dispersion was mixed by pipetting for a few seconds. The change in fluorescence intensity (λ_em = 585 nm) was monitored with a microplate reader under periodic shaking.

Confocal imaging measurements: 20 μL peptide coacervate dispersion (10 mg mL⁻¹ in HEPES/PBS buffer, pH ~ 8) was mixed with 0.2 μL Ru solution (0.5 mg mL⁻¹ in DMSO) by pipetting. The mixture was then treated with 0.2 μL caged resorufin (0.5 mg mL⁻¹ in DMSO). The emission intensity at λ_em = 585 nm was then recorded by confocal imaging.