Description
Droplet-based microfluidics is a growing technique used in biology, chemistry and material science, enabling high-throughput applications in the fields of synthetic biology and single-cell biomedical analysis. These systems rely on stable, monodisperse water-in-fluorinated oil (w/o) droplets, typically stabilized by fluorinated surfactants. Current diblock and triblock commercial copolymers surfactants are based on poly(ethylene glycol) (PEG) and perfluoropolyether (PFPE) chains (PEG-PFPE), however, their limited chemical reactivity restricts further functionalization and application versatility.
Here we report on a new class of comb-shaped oligomeric fluorosurfactants consisting of a hydrophilic N vinylformamide (NVF) backbone functionalized with long PFPE side chains. The NVF backbone is water-soluble, biocompatible, and readily functionalizable through partial hydrolysis to N vinylamine, enabling the introduction of additional chemical moieties. The synthesis involves cationic oligomerization of NVF, controlled hydrolysis, and subsequent side-chain and functional group conjugation, providing a modular and customizable surfactant platform.
The designed comb-shaped fluorosurfactants stabilize droplets for several weeks and show preliminary biocompatibility. Functionalized variants incorporating fluorescein or biotin were successfully produced, enabling fluorescence labelling and biomolecular capture at droplet interfaces. This modular surfactant system expands the functional capabilities of droplet microfluidics and opens new opportunities for advanced bio- and materials-based applications.