10.1021/jacs.9b05195.s001 Wei Chen Wei Chen Chi-An Cheng Chi-An Cheng Emily D. Cosco Emily D. Cosco Shyam Ramakrishnan Shyam Ramakrishnan Jakob G. P. Lingg Jakob G. P. Lingg Oliver T. Bruns Oliver T. Bruns Jeffrey I. Zink Jeffrey I. Zink Ellen M. Sletten Ellen M. Sletten Shortwave Infrared Imaging with J‑Aggregates Stabilized in Hollow Mesoporous Silica Nanoparticles American Chemical Society 2019 NIR fluorophore IR -140 PEGylated HMSNs 980 nm excitation SWIR light J-aggregate SWIR imaging mesoporous silica nanoparticles resolution imaging 1000 nm Hollow Mesoporous Silica Nanoparticles Tissue red-shifted SWIR contrast agents biocompatible contrast agents 2019-08-02 18:43:34 Journal contribution https://acs.figshare.com/articles/journal_contribution/Shortwave_Infrared_Imaging_with_J_Aggregates_Stabilized_in_Hollow_Mesoporous_Silica_Nanoparticles/9232589 Tissue is translucent to shortwave infrared (SWIR) light, rendering optical imaging superior in this region. However, the widespread use of optical SWIR imaging has been limited, in part, by the lack of bright, biocompatible contrast agents that absorb and emit light above 1000 nm. J-Aggregation offers a means to transform stable, near-infrared (NIR) fluorophores into red-shifted SWIR contrast agents. Here we demonstrate that J-aggregates of NIR fluorophore IR-140 can be prepared inside hollow mesoporous silica nanoparticles (HMSNs) to result in nanomaterials that absorb and emit SWIR light. The J-aggregates inside PEGylated HMSNs are stable for multiple weeks in buffer and enable high resolution imaging <i>in vivo</i> with 980 nm excitation.