Plataforma novedosa de doble emisión fluorescente para la detección sensible de dehidroacetato de sodio en alimentos...

A fast fluorescent dual-emission platform for sensitive detection of sodium dehydroacetate (SDHA) in food is established utilizing bimetallic organic frameworks (Eu@Zr-MOFs). Eu@Zr-MOFs show two fluorescent emissions at 430 nm and 616 nm under single excitation wavelength of 290 nm. Two peaks separated by 180 nm help to eliminate environmental interference and improve the accuracy. In the presence of SDHA, fluorescent intensity at 430 nm and 616 nm shows fluorescent quenching within 1 min. Fluorescent lifetime results show that fluorescent quenching is a static quenching mode. Fluorescent quenching may be ascribed to the diketone structure of SDHA coordinated with Eu³⁺ and internal filtering effect. The logarithm of fluorescent intensity (lgI_{430 nm} * I_{616 nm}) has linear relationship with the concentration of SDHA from 0.1 µM to 200 µM with a limit of detection of 31.6 nM. More conveniently, it also achieves visual detection of SDHA through fluorescent color by portable UV lamp and smartphone "color capture" mode. The platform is applied to detect SDHA in fermented and baked food samples. Thus it is an efficient and sensitive fluorescent ratio method for SDHA detection with fast response, high selectivity and accuracy.