Ag₂S Biocompatible Ensembles as Dual OCT Contrast Agents and NIR Ocular Imaging Probes

Abstract

Ag2S 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 Ag2S 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.

Versatile Metal–Organic Framework Incorporating Ag2S for Constructing a Photoelectrochemical Immunosensor for Two Breast Cancer Markers

“…Furthermore, we could know the chemical state of the dopant Ag 2 S by means of high-resolution XPS. The XPS spectrum of S 2p in Figure e shows that the peaks at 162.47 and 161.22 eV correspond to the binding energies of S 2P 1/2 and S 2P 3/2 orbitals, respectively, indicating the presence of S 2– for S in the composite . For Ag in the composite, the peaks at 368.3 and 374.3 eV were related to Ag 3d 5/2 and Ag 3d 2/3 orbitals, respectively, demonstrating the form of Ag + …”