Synthesis of amphiphilic pyrene–BODIPY sulfonates with self-assembling properties

Self-assembly processes provide a powerful tool for the synthesis of nanostructures with tailored properties. Here, amphiphilic BODIPY fluorophores bearing pyrene and styryl sulfonates have been designed to couple water solubility with cell membrane permeability. The probes form nanoaggregates in aqueous media and show a red-shifted emission. Spectroscopic studies reveal an efficient energy transfer from pyrene donor subunit to the BODIPY acceptor and an extended conjugation from styryl units. Probes have been synthesized via Knoevenagel condensation on the BODIPY core1 to introduce styryl units, followed by sulfonation with propanesultone under basic conditions (Figure 1). The sulfonate groups allow the water solubility while the pyrene unit can enable π–π stacking interactions for a potential integration with graphene and carbon surfaces for signal amplification and surface readouts.2 Because the BODIPY core is readily post-functionalized, emission and affinity can be tuned without losing amphiphilicity, allowing task-specific variants. Overall, these amphiphilic pyrene–BODIPY sulfonates provide a compact and tunable platform that combine self-assembly in solution with reliable cellular imaging and sensor design. They are straightforward to prepare, work at low concentrations, and can be adapted to workflows in imaging, microfluidic assays, and materialintegrated biosensors.3