Sousa Castillo, AnaRodríguez Couceiro, JoséTomás Gamasa, MaríaMariño López, AndreaLópez García, FernandoBaaziz, WalidErsen, OvidiuComesaña Hermo, MiguelMascareñas Cid, José LuisCorrea Duarte, Miguel Ángel2020-11-032021-09-292020Nano Lett. 2020, 20, 10, 7068–70761530-6984http://hdl.handle.net/10347/23536This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.nanolett.0c02180Major current challenges in nano-biotechnology and nano-biomedicine include the implementation of predesigned chemical reactions in biological environments. In this context, heterogeneous catalysis is emerging as a promising approach to extend the richness of organic chemistry onto the complex environments inherent to living systems. Herein we report the design and synthesis of hybrid heterogeneous catalysts capable of being remotely activated by near-infrared (NIR) light for the performance of selective photocatalytic chemical transformations in biological media. This strategy is based on the synergistic integration of Au and TiO2 nanoparticles within mesoporous hollow silica capsules, thus permitting an efficient hot-electron injection from the metal to the semiconductor within the interior of the capsule that leads to a confined production of reactive oxygen species. These hybrid materials can also work as smart NIR-responsive nanoreactors inside living mammalian cells, a cutting-edge advance toward the development of photoresponsive theranostic platformseng© 2020 American Chemical Society. This article may be used for non-commercial purposes in accordance with ACS Terms and Conditions for Use of Self-Archived VersionsPhotocatalysisBioorthogonal chemistryPlasmonic hot electronsHybrid nanocapsulesjournal article10.1021/acs.nanolett.0c021801530-6992open access