Surface-enhanced Raman scattering(SERS)substrates based on chemical mechanism(CM)have received widespread attentions for the stable and repeatable signal output due to their excellent chemical stability,uniform molecu...Surface-enhanced Raman scattering(SERS)substrates based on chemical mechanism(CM)have received widespread attentions for the stable and repeatable signal output due to their excellent chemical stability,uniform molecular adsorption and controllable molecular orientation.However,it remains huge challenges to achieve the optimal SERS signal for diverse molecules with different band structures on the same substrate.Herein,we demonstrate a graphene oxide(GO)energy band regulation strategy through ferroelectric polarization to facilitate the charge transfer process for improving SERS activity.The Fermi level(Ef)of GO can be flexibly manipulated by adjusting the ferroelectric polarization direction or the temperature of the ferroelectric substrate.Experimentally,kelvin probe force microscopy(KPFM)is employed to quantitatively analyze the Ef of GO.Theoretically,the density functional theory calculations are also performed to verify the proposed modulation mechanism.Consequently,the SERS response of probe molecules with different band structures(R6G,CV,MB,PNTP)can be improved through polarization direction or temperature changes without the necessity to redesign the SERS substrate.This work provides a novel insight into the SERS substrate design based on CM and is expected to be applied to other two-dimensional materials.展开更多
Herein,a thermoelectric induced surface-enhanced Raman scattering(SERS)substrate consisting of ZnO nanorod arrays and metal nanoparticles is proposed.The intensities of SERS signals are further enhanced by an order of...Herein,a thermoelectric induced surface-enhanced Raman scattering(SERS)substrate consisting of ZnO nanorod arrays and metal nanoparticles is proposed.The intensities of SERS signals are further enhanced by an order of magnitude and the limit of detection(LOD)for the molecules is reduced by at least one order of magnitude after the application of a thermoelectric potential.The enhancement mechanism is analyzed carefully and thoroughly based on the experimental and theoretical results,thus proving that the thermoelectric-induced enhancement of the SERS signals should be classified as a chemical contribution.Furthermore,it is proved that the electric regulation mechanism is universally applicable,and the fabricated substrate realizes enormous enhancements for various types of molecules,such as rhodamine 6G,methyl orange,crystal violet,amaranth,and biological molecules.Additionally,the proposed electric-induced SERS(E-SERS)substrate is also realized to monitor and manipulate the plasmon-activated redox reactions.We believe that this study can promote the course of the research on ESERS and plasmon-enhanced photocatalysts.展开更多
基金financial supports from the National Natural Science Foundation of China (11974222,12004226,12174229,11904214)Natural Science Foundation of Shandong Province (ZR2022YQ02,ZR2020QA075)+2 种基金Qingchuang Science and Technology Plan of Shandong Province (2021KJ006,2019KJJ014,2019KJJ017)Taishan Scholars Program of Shandong Province (tsqn202306152)China Postdoctoral Science Foundation(2019M662423),Shandong Post-Doctoral Innovation Project (202002021).
文摘Surface-enhanced Raman scattering(SERS)substrates based on chemical mechanism(CM)have received widespread attentions for the stable and repeatable signal output due to their excellent chemical stability,uniform molecular adsorption and controllable molecular orientation.However,it remains huge challenges to achieve the optimal SERS signal for diverse molecules with different band structures on the same substrate.Herein,we demonstrate a graphene oxide(GO)energy band regulation strategy through ferroelectric polarization to facilitate the charge transfer process for improving SERS activity.The Fermi level(Ef)of GO can be flexibly manipulated by adjusting the ferroelectric polarization direction or the temperature of the ferroelectric substrate.Experimentally,kelvin probe force microscopy(KPFM)is employed to quantitatively analyze the Ef of GO.Theoretically,the density functional theory calculations are also performed to verify the proposed modulation mechanism.Consequently,the SERS response of probe molecules with different band structures(R6G,CV,MB,PNTP)can be improved through polarization direction or temperature changes without the necessity to redesign the SERS substrate.This work provides a novel insight into the SERS substrate design based on CM and is expected to be applied to other two-dimensional materials.
基金the financial support from the National Natural Science Foundation of China(Nos.11974222,12004226,12174229,and 11904214)the Natural Science Foundation of Shandong Province(No.ZR2020QA075)+1 种基金the Qingchuang Science and Technology Plan of Shandong Province(No.2021KJ006)the China Postdoctoral Science Foundation(No.2019M662423).
文摘Herein,a thermoelectric induced surface-enhanced Raman scattering(SERS)substrate consisting of ZnO nanorod arrays and metal nanoparticles is proposed.The intensities of SERS signals are further enhanced by an order of magnitude and the limit of detection(LOD)for the molecules is reduced by at least one order of magnitude after the application of a thermoelectric potential.The enhancement mechanism is analyzed carefully and thoroughly based on the experimental and theoretical results,thus proving that the thermoelectric-induced enhancement of the SERS signals should be classified as a chemical contribution.Furthermore,it is proved that the electric regulation mechanism is universally applicable,and the fabricated substrate realizes enormous enhancements for various types of molecules,such as rhodamine 6G,methyl orange,crystal violet,amaranth,and biological molecules.Additionally,the proposed electric-induced SERS(E-SERS)substrate is also realized to monitor and manipulate the plasmon-activated redox reactions.We believe that this study can promote the course of the research on ESERS and plasmon-enhanced photocatalysts.
