@article{rao_gong_shahid_liu_mao_zhang_2025, title={Functional super-resolution microscopy of fibers and polymers: convergence of artificial and biological systems at the nanoscale}, url={https://doi.org/10.1039/D5NH00729A}, DOI={10.1039/d5nh00729a}, abstractNote={The diagram highlights functional SRM as a bridge between nanoscale studies of biological and artificial fibers and polymers where advances in SRM enable study of synthetic systems and polymer principles guide understanding of complex natural fiber.}, journal={Nanoscale Horizons}, author={Rao, Si-Jia and Gong, Xiayi and Shahid, Md Abul and Liu, Yunshu and Mao, Hongjing and Zhang, Yang}, year={2025}, month={Dec} }
 @article{tomassini_liu_zheng_shahid_singh_singh_piedra_gong_hayter_singh_et al._2025, title={Photoactivation of BODIPY Fluorescence with Green Light}, volume={6}, DOI={10.1021/acs.joc.5c00668}, abstractNote={Existing synthetic dyes with photoactivatable fluorescence demand ultraviolet radiation or, at best, violet light for fluorescence photoactivation. Illumination of biological samples within this range of relatively short wavelengths, however, causes significant photodamage. Strategies for the photochemical generation of fluorescent products under irradiation at wavelengths longer than 500 nm with moderate power densities are urgently needed to enable live-cell imaging with negligible phototoxicity. We identified a possible structural design to satisfy these stringent irradiation requirements. Specifically, we demonstrated that illumination of a borondipyrromethene (BODIPY) chromophore in the green region of the visible spectrum cleaves an adjacent oxazine heterocycle to form a fluorescent product with an emission in the red spectral window. We successfully photoactivated this compound with a 561 nm laser and localized single molecules of the fluorescent product with nanometer precision under 581 nm excitation, even in the interior of live cells. Indeed, we reconstructed subdiffraction images of the nanostructured lysosomes of the labeled cells under such unprecedented illumination conditions. Our results clearly indicate that this photochemical strategy for fluorescence photoactivation is a viable one for the realization of very-much needed photoactivatable synthetic dyes for super-resolution imaging with live-cell compatible irradiation requirements.}, journal={The Journal of Organic Chemistry}, author={Tomassini, Andrea and Liu, Yunshu and Zheng, Yeting and Shahid, Md Abul and Singh, Amrita and Singh, Ambarish Kumar and Piedra, William M. and Gong, Xiayi and Hayter, Colin E. and Singh, Keiran I. and et al.}, year={2025}, month={Jun} }
 @article{qi_liu_puranik_patra_svindrych_gong_she_zhang_aprahamian_2025, title={Photoswitchable Fluorescent Hydrazone for Super-Resolution Cell Membrane Imaging}, volume={5}, url={https://doi.org/10.1021/jacs.5c02669}, DOI={10.1021/jacs.5c02669}, abstractNote={Advancing the field of super-resolution microscopy will require the design and optimization of new molecular probes whose emission can be toggled "ON" and "OFF" using light. Recently, we reported on a hydrazone photochrome (<b>1</b>) whose emission can be photoswitched on demand, although its low brightness and UV light-dependent back isomerization limited its use in such applications. Here, we report on the optimization of this parent fluorophore by replacing its dimethylamine electron-donating group with conformationally more rigid groups, namely, azetidine (<b>2</b>), 3,3-difluoroazetidine (<b>3</b>), and julolidine (<b>4</b>). This structural change resulted in enhanced brightness (i.e., extinction coefficient multiplied by fluorescence quantum yield), specifically in <b>4</b> because of its rigidity and ED capability. Next, three electron push-pull hydrazones (<b>5</b>-<b>7</b>) were designed based on the scaffold of <b>4</b>, using cyano, nitro, or dicyanovinyl, respectively, as the electron-withdrawing groups, resulting in the progressive red-shifting of the photoswitching wavelengths into the visible region and further enhancement in brightness. Finally, fluorogenic probe <b>8</b> was developed based on parent compound <b>7</b>, which could be activated solely with visible light and used in the super-resolution imaging of fixed-cell and live-cell plasma membranes with average localization precisions of 17 and 25 nm, respectively.}, journal={Journal of the American Chemical Society}, author={Qi, Qingkai and Liu, Yunshu and Puranik, Vedang and Patra, Shefali and Svindrych, Zdenek and Gong, Xiayi and She, Ziwei and Zhang, Yang and Aprahamian, Ivan}, year={2025}, month={May} }