Improved fluorescence properties of core–sheath electrospun nanofibers sensitized by silver nanoparticles

• Tb(acac)3phen/PLLA//Ag-NPs/PVP core–sheath nanofibers were prepared.
• Ag and Tb(acac)3phen uniformly dispersed in outer and inner layers, respectively.
• The outer Ag-NPs improved the fluorescence of the inner Tb(acac)3phen.
• The novel core–sheath nanofibers showed excellent fluorescence properties.

Silver nanoparticles (Ag-NPs) were used to enhance the fluorescence properties of nanofibers containing the Tb(acac)3phen (Tb = terbium, acac = acetylacetone, phen = 1,10-phenanthroline) complex. Tb(acac)3phen/PLLA//Ag-NPs/PVP (PLLA = polylacticacid, PVP = polyvinylpyrrolidone) core–sheath fluorescence nanofibers were prepared by coaxial electrospinning. SEM images demonstrated that the fibers had an average diameter of 550 nm. TEM images illustrated that the Ag-NPs and Tb(acac)3phen were uniformly dispersed in the outer and inner fibrous layers in the form of nanoparticles and molecular clusters, respectively. The fluorescence intensity of the Tb(acac)3phen/PLLA//Ag-NPs/PVP core–sheath nanofibers with a molar ratio Ag/Tb of 1 increased by 69%, the quantum efficiency increased by 53%, and the fluorescence lifetime increased by 4% over those of the fibers without Ag-NPs because of the localized surface plasmon resonance (LSPR) effect of Ag-NPs. The prepared fibers with a core–sheath structure have great potential in a wide range of fluorescence applications.