Surface‐Enhanced Raman Spectra Promoted by a Finger Press in an All‐Solid‐State Flexible Energy Conversion and Storage Film

Abstract

Electrochemically up-regulated surface-enhanced Raman spectroscopy (E-SERS) effectively increases Raman signal intensities. However, the instrumental requirements and the conventional measurement conditions in an electrolyte cell have hampered its application in fast and on-site detection. To circumvent the inconveniences of E-SERS, we propose a self-energizing substrate that provides electrical potential by converting film deformation from a finger press into stored electrical energy. The substrate combines an energy conversion film and a SERS-active Ag nanowire layer. A composite film prepared from a piezoelectric polymer matrix and surface-engineered rGO that simultaneously presents high permittivity and low dielectric loss is the key component herein. Using our substrate, increased E-SERS signals up to 10 times from a variety of molecules were obtained in the open air. Various tests on real-life sample surfaces demonstrated the potentials of the substrate in fast on-site detection.

Preparation and performance of poly(ethylene oxide)‐based composite solid electrolyte for all solid‐state lithium batteries

“…As one of the most competitive candidates, PEO‐based solid electrolyte complexed with lithium salt exhibits a certain degree of ionic conductivity and flexibility. These features make it possible to develop flexible device . As a matter of the fact, the polymer, PEO, plays the part of host for ions and the migration of lithium ion generally occurs in different oxygen atoms.…”

Electric Field-Modulated Surface Enhanced Raman Spectroscopy by PVDF/Ag Hybrid

“…where e, ε 0 and m e are electron charge, vacuum permittivity and effective mass of electrons, respectively. In our experiments, partial Ag NWs nearby the PVDF can discharge due to the transfer of an electron under the influence of positive potential by piezoelectric effect 31,34,35 . The decreased electrons in Ag NWs subsequently lead to the change of the ε(ω) owing to the alteration of ω p and Ω L , represented as www.nature.com/scientificreports www.nature.com/scientificreports/…”

“…What's more, as shown in Fig. 3(f), these induced electrons bring a change to ε(ω) and further lead to a redshift of the plasmon resonance of the AgNWs, which better matching with the incident laser (532 nm) used in the Raman measurement and benefits the regulation of the LSP property of the SERS substrate 31,35,36 .…”

“…Among the numerous piezoelectric materials, flexible polyvinylidene fluoride (PVDF) with remarkable piezoelectric effect has been widely researched as the representative material 29,30 . Compared with the scheme to conduct the flexible insulative polymer, the PVDF can provide an internal electric field under the pressure, which can serve as an ideal E-SERS substrate 31,32 . Besides the excellent flexibility for in-situ detection, the low Raman cross-section of the PVDF makes it has little influence on the identification of the probe molecular.…”

Modified sepiolite/PVDF‐HFP composite film with enhanced piezoelectric and dielectric properties

“…To satisfy the high integration of modern microelectronics, multiple performances such as dielectricity, piezoelectricity, pyroelectricity, and photoelectricity were realized in single material or device. For the piezoelectric–dielectric film, the energy conversion and storage abilities could be achieved simultaneously and the film has been used as an energy supplier to improve the performances of photocatalysis and Raman enhancement . Thus, the development of new materials with both piezoelectric and dielectric properties is very meaningful to further applications in the energy supply.…”