Ag<sub>2</sub>S Biocompatible Ensembles as Dual OCT Contrast Agents and NIR Ocular Imaging Probes
Amalia Coro, Ada Herrero Ruiz, Mateo Pazo‐González, Alonso Sánchez‐Cruz, Tobias Busch, Alejandro Hernández Medel, Erving Ximendes, Dirk H. Ortgies, Rosalía López‐Méndez, Ana Espinosa, Dorleta Jiménez de Aberasturi, Daniel Jaque, Núria Fernández, Enrique J. de la Rosa, Catalina Hernández‐Sánchez, Emma Martín Rodríguez, Beatriz H. Juárez
Abstract
Abstract Ag 2 S nanoparticles (NPs) emerge as a unique system that simultaneously features in vivo near‐infrared (NIR) imaging, remote heating, and low toxicity thermal sensing. In this work, their capabilities are extended into the fields of optical coherence tomography (OCT), as contrast agents, and NIR probes in both ex vivo and in vivo experiments in eyeballs. The new dual property for ocular imaging is obtained by the preparation of Ag 2 S NPs ensembles with a biocompatible amphiphilic block copolymer. Rather than a classical ligand exchange, where surface traps may arise due to incomplete replacement of surface sites, the use of this polymer provides a protective extra layer that preserves the photoluminescence properties of the NPs, and the procedure allows for the controlled preparation of submicrometric scattering centers. The resulting NPs ensembles show extraordinary colloidal stability with time and biocompatibility, enhancing the contrast in OCT with simultaneous NIR imaging in the second biological window.