Smart Fluorescence Materials that Are Controllable by Hydrostatic Pressure: Peptide-Pyrene Conjugates

Fluorogens or luminescence materials that show manipulatable emissive responses toward various external stimuli, such as, temperature, solvent, salt, and pH, hold great promise for some applications. Hydrostatic pressure, as one external stimulus, can manipulate conformational changes in the ground state and subsequent photophysical properties in the excited state of an appropriately designed material. In this study, we controlled not only the chiroptical but also the emissive properties of smart fluorescence materials, namely peptide-pyrene conjugates, and also examined the origins of the optical properties by means of several spectroscopic techniques under high pressure. The location of the chromophores and the appended bulky substituent on the peptide scaffold play pivotal roles in influencing the pressure-induced properties. The present work gives new perspectives for energy-related luminescent materials which respond to hydrostatic pressure, providing an attractive alternative to other common external stimuli.