Fluorometric determination of dopamine by using a terbium (III) inorganic-organic network

A hybrid organic-inorganic optical probe was developed by using silylated precursors (including tetraethoxy silane and aminopropyltriethoxysilane), ferroferric oxide (Fe 3 O 4 ) and lanthanide coordination units. Cross-linking condensation warrants chemical stability. The shape and size of the resulting nanoparticles can be adjusted to around 40–60 nm. On photo-excitation at 313 nm, they display green fluorescence (peaking at 545 nm) which is strongly enhanced on addition of dopamine in tris-buffer solution (pH = 8.5). Spectroscopic studies demonstrate that this assay exhibits good selectivity for dopamine and has a 0.82 μM detection limit. The hybrid structures can be separated and recycled due to the magnetic properties of Fe 3 O 4 . The feasibility of dopamine analysis in human serum sample has been assessed. Schematic presentation of a terbium organic-inorganic material whose fluorescence is selectively enhanced by dopamine. The material can be repeatedly used because it can be regenerated by treatment with acids and magnetic separation.