Composite nanofiber meshes of well-aligned polyacrylonitrile (PAN)/FeCo nanofibers containing nanoparticles (NPs) were successfully fabricated by a magnetic-field-assisted electrospinning technology, which was confirmed to be a favorable method for the preparation of aligned composite nanofibers in this article. Meanwhile, FeCo NPs, with a particle size of approximately 60 nm, were synthesized using a hydrothermal route. The nanocomposite fibers were prepared by an electrospun solution of PAN containing 0, 2, 4, and 6 wt% NPs. The as-spun nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. Both the diameters and the degree of alignment of the composite nanofibers decreased with the increase in voltage and increased with the increase in FeCo content. The composite nanofibers exhibited superior ordered performance, with the highest alignment value being 97%. Due to the highly ordered alignment structures, the composite nanofiber meshes showed large anisotropic magnetic property. In particular, the saturation magnetization of the composite nanofiber films in the parallel and perpendicular directions of the fiber axis were 42 emu/g and 19.5 emu/g, respectively. Meanwhile, the remanence also exhibited distinction in different directions (parallel: 2.01 emu/g; perpendicular: 0.86 emu/g).

Few-layer chemical vapor deposition (CVD) graphene was successively wet transferred on magnetron sputtering Ag/TiO2 film to develop a recyclable surface-enhanced Raman scattering (SERS) substrate with high sensitivity, stability and reproducibility...

The development of a facile surface-enhanced Raman scattering (SERS) sensor for the on-site detection of trace molecules in liquid phase is a compelling need. In this paper, a three-dimensional (3D) dendritic Au–Ag nanostructure was constructed by a two-step electro displacement reaction in a capillary tube for the on-site liquid phase detection of trace molecules. The multiplasmon resonance mechanism of the dendritic Au–Ag structure was simulated using the finite-difference time domain (FDTD) method. It was confirmed that the highly branched 3D structure promoted the formation of high-density “hot spots” and interacted with the gold nanoparticles at the dendrite tip, gap, and surface to maximize the spatial electric field, which allowed for high signal intensification to be observed. More importantly, the unique structure of the capillary made it possible to achieve the on-site detection of trace molecules in liquids. Using Rhodamine 6G (R6G) solution as a model molecule, the 3D dendritic Au–Ag substrate exhibited a high detection sensitivity (10−13 mol/L). Furthermore, the developed sensor was applied to the detection of antibacterial agents, ciprofloxacin (CIP), with clear Raman characteristic peaks observed even at concentrations as low as 10−9 mol/L. The results demonstrated that the 3D dendritic Au–Ag sensor could successfully realize the rapid on-site SERS detection of trace molecules in liquids, providing a promising platform for ultrasensitive and on-site liquid sample analysis.

In this paper, a highly active surface enhanced Raman scattering (SERS) substrate based on three-dimensional (3D) dendritic silver nanostructure was constructed in microfluidic channel by one-step electrodisplacement reaction for in-situ...