A novel fluorescent sensor based on lanthanide-doped polyoxometalate for ultrasensitive detection of phytic acid

Recently, lanthanide-doped polyoxometalates have garnered significant attention as optical nanosensors. In this study, a novel fluorescence sensing platform for phytic acid detection based on fluorescence quenching was developed. The tungsten europium heteropolyoxometalate Na₉EuW₁₀O₃₆ was prepared under mild conditions, emitting characteristic emission peaks of europium ions at 556, 591, 618, 649, and 700 nm. The fluorescence sensing of phytic acid by Na₉EuW₁₀O₃₆ was achieved based on the action of static quench. The linear range of the method for the detection of phytic acid was 1–100 μmol·L⁻¹ with a linear equation of the relative fluorescence intensity F₀/F = 0.0256 [c(PA)] + 0.9489 (R² = 0.9930), and the detection limit of 0.51 μmol·L⁻¹. The detection of phytic acid in aquatic products was achieved through spiked tests on Litopenaeus vannamei and frozen Larimichthys with recoveries ranging from 96.68% to 116.04%, and the relative standard deviation is less than 6%, indicating the strong application potential.