Improvements in photostability and sensing properties of EuVO₄ nanoparticles by microwave-assisted sol–gel route for detection of H₂O₂ vapors

The inorganic thin-film fluorescence probe, with the advantages of long life span and high sensitivity, has attracted much attention in explosive detection. The poor ultraviolet absorption and lack of an aromatic ring make peroxide-based explosives very hard to detect. As the signature compound of peroxide-based explosives, H₂O₂ vapor detection became more and more important. Rare-earth-doped vanadate is considered to be a suitable material for the detection of hydrogen peroxide due to the quenching of its fluorescence in the presence of hydrogen peroxide. Its only drawback lies on its poor photostability. In this work, we have developed a new synthesis to limit the photobleaching of EuVO₄-based films. We propose herein an original protocol using microwave-assisted sol–gel route. The photostability of luminescent EuVO₄ has been achieved and the sensitivity has been greatly increased. The detection limit for H₂O₂ vapor is as low as 100 parts per billion (ppb). The characterization of these nanoparticles by photoelectron spectroscopy clearly correlates their sensitivity to H₂O₂ to the surface chemistry.