Nanoscale synthesis of polyoxovanadate organic-inorganic hybrid for naked-eye dopamine detection

Abstract

Decavanadate based compounds as a class of polyoxometalates family are known for their wide range of applications in chemical, biological, and physical sciences. Considering the size-dependent chemical properties of polyoxometalates and the unique properties of decavanadates, the nanoscale (HNic)6[V10O28].H2O (1), an organic-inorganic hybrid compound was synthesized using ultrasound and in the presence of a weak solvent. The nanostructures were characterized by FT-IR spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and elemental analysis. The results showed that by increasing the amount of the weak solvent, the size and crystallinity of nanoparticles decreased. Optical studies revealed a green emission with a maximum at 530 nm from nanoscale 1 which is assigned to O→V charge transfer transition and it was used for dopamine (DA) detection. Interestingly, nanoscale 1 catalyzed the in-situ formation of polydopamine nanoparticles, the formation of which decreased the fluorescence intensity of nanoscale 1 which was successfully utilized for naked-eye dopamine molecules detection.