Selective dual sensing strategy for free and vitamin D micelles in food samples based on S,N-GQDs photoinduced electron transfer.

A reliable nanotechnological sensing strategy, based on an S,N-co-doped graphene quantum dot (GQD) platform, has been developed to distinctly detect two key variants of vitamin D, specifically the free (VD) and the nanoencapsulated form (VDMs). For this purpose, food-grade vitamin D micelles were self-assembled using a low-energy procedure (droplet size: 49.6 nm, polydispersity index: 0.

Distinctive sensing nanotool for free and nanoencapsulated quercetin discrimination based on S,N co-doped graphene dots.

A selective and sensitive fluorescent nanoprobe (sulfur and nitrogen co-doped graphene quantum dots, S,N-GQDs) was designed for both detection and discrimination between free and quercetin-loaded nanoemulsion in food samples of diverse nature. Quercetin nanoemulsions (Q-NEs) were synthesized by a phase inversion temperature (PIT) procedure, while S,N-GQDs were synthesized using a bottom-up methodology by means of simple hydrothermal treatment of citric acid and cysteamine. Both synthetized nanomaterials (analyte and fluorescent probe), were carefully characterized through advanced spectroscopic and high-resolution microscopic techniques.