Highly sensitive and selective determination of fluorine ion by graphene oxide/nanogold resonance Rayleigh scattering-energy transfer analytical platform

• GO/NG was used as RRS spectral probe.
• RRS-ET taken place from GO/NG to the ternary complex.
• A selective RRS-ET method was developed for trace fluorine.
• Fluorine in real samples was analyzed by this RRS-ET method.

In pH 4.0 acetate buffer solution, fluorine ions react with fluorine reagent (FR) and La(III) to generate blue ternary complex that exhibited strong absorption at about 370 nm. Upon addition of graphene oxide/nanogold (GO/NG) as resonance Rayleigh scattering (RRS) spectral probe with strong RRS peak at 370 nm, the color changed to gray, and the RRS intensity decreased with the increase of fluorine ion concentration due to the RRS energy transfer (RRSET) from GO/NG to the complex. Under the selected condition, the decreased RRS peak ΔI370nm was linear to fluorine ion concentration in the range of 6.0 × 10−8–1.3 × 10−5 mol/L, with a detection limit of 3.0 × 10−8 mol/L F−. This RRSET method was applied to the analysis of fluorine in toothpaste and water samples, with satisfactory results.