Luminescent europium(III)-organic framework for visual and on-site detection of hydrogen peroxide via a tablet computer.

A luminescent metal-organic framework of type Eu(III)-MOF has been fabricated for visual and on-site fluorometric determination of hydrogen peroxide (HO) via a tablet computer. The maximum excitation and emission peaks of type Eu(III)-MOF were found at λex = 290 nm and λem = 615 nm, respectively. The average length of Eu-MOF is 1.21 ± 0.07 μm. In the presence of the target HO, Fe is transmitted into Fe via Fenton reaction, leading to a fluorescence quenching of Eu-MOF. Therefore, visible color change occurred from bright red into colorless. Interestingly, by means of tablet computer's digital camera and ImageJ software, fluorescent signals were captured and transduced into digital parameters, resulting in a linear relationship between fluorescence intensity and the concentration of HO. As a result, the determination of HO without the aid of complicated instruments is achieved in the range 2.0 μM to 0.2 mM with a detection limit of 1.02 μM. Our approach has been successfully applied to quantify HO in serum, urine, and waste water with good recovery and precision (< 2.5% RSD). Besides, our assay has been exploited for visual detection of HO released from HepG2 cells with the advantages of portability and accuracy. Moreover, the strategy displays acceptable selectivity and stability. Hence, our assay provides an alternative practical method for on-site determination of HO without the need for instruments. Graphical abstract Schematic representation of the synthesis procedure of a luminescent Eu-MOF, which has been successfully applied for on-site detection of HO via Fenton reaction and imaging analysis technique. The method exhibits handheld and accuracy for HO determination, holding the potential for biochemical and clinical applications in remote regions.