Abstract
The Cover Feature illustrates the fluorescence photoactivation of polymer nanoparticles doped with a BODIPY–oxazine dyad in alginate hydrogel beads. The photoinduced dissociation of the oxazine ring brings the BODIPY chromophore in conjugation with an indole auxochrome in the photochemical product to shift its absorption and emission bands bathochromically. These spectral changes allow the excitation of reactant and product at same wavelength and the collection of their emissions in partially‐resolved spectral windows. The photocleavable oxazine component can be substituted with styryl groups to regulate the absorption properties without preventing photoactivation. More information can be found in the Article by F. M Raymo and co‐workers on page 332 in Issue 5, 2020 (DOI: 10.1002/cptc.201900276).