Core–Shell Architecture in Poly(3-hexylthiophene) Nanoparticles: Tuning of the Photophysical Properties for Enhanced Neuronal Photostimulation
Jonathan Barsotti, Sara Perotto, Andrea Candini, Elisabetta Colombo, Franco V. A. Camargo, Stefano Di Marco, Mattia Zangoli, Samim Sardar, Alex J. Barker, Cosimo D’Andrea, Giulio Cerullo, Shlomo Rozen, Fabio Benfenati, Francesca Di Maria, Guglielmo Lanzani
Abstract
This study shows that entirely thiophene-based core@shell nanoparticles, in which the shell is made of the oxidized form of the core polymer (P3HT@PTDO x NPs), result in a type II interface at the particle surface. This enables the development of advanced photon nanotransducers with unique chemical–physical and biofunctional properties due to the core@shell nanoarchitecture. We demonstrate that P3HT@PTDO x NPs present a different spatial localization of the excitation energy with respect to the nonoxidized NPs, showing a prevalence of surface states as a result of a different alignment of the HOMO/LUMO energy levels between the core and shell. This allows for the efficient photostimulation of retinal neurons. Indeed, thanks to the stronger and longer-lived charge separation, P3HT@PTDO x NPs, administered subretinally in degenerate retinas from the blind Royal College of Surgeons rats, are more effective in photostimulation of inner retinal neurons than the gold standard P3HT NPs.