Sensitive Cu2+detection by reversible on-off fluorescence using Eu3+complexes in SiO2, in chitosan/polyethylene oxide nanofibers

Trace amounts of heavy metal ions in the human body are essential for maintaining health. However, heavy metal ion excess or deficiency causes toxicity or disease. This study examines the sensitivity of luminescent europium complexes for the detection of Cu2+. Here, Eu3+ is complexed with1,10phenanthroline (phen) and 4,40,4-trimethyltriphenylamine (TTA) to form luminescent [Eu3+(TTA)3phen] complexes, encapsulated in silica (SiO2) nanoparticles. The silica nanoparticles are then formed into a composite with a blend of chitosan and polyethylene oxide (PEO), to make electrospun nanofibers. The combination of Eu3+ complexes with SiO2 nanoparticles doped in chitosan enhances the fluorescence performance. Photophysical measurements show that when the Cu2+ concentration is 100 lmol/L, the fluorescence of the composite chitosan nanofibers can be quickly and sensitively quenched, and that concentrations as low as 10 lmol/L Cu2+ can be detected. Furthermore, the use of chitosan and PEO to

Automated summary

This study investigates the sensitivity of luminescent europium complexes for detecting Cu2+ ions. By combining Eu3+ complexes with SiO2 nanoparticles doped in chitosan, the fluorescence performance is enhanced, enabling the detection of Cu2+ concentrations as low as 10 lmol/L.