Constructing surface-enhanced Raman scattering(SERS)substrates is a recognized and effective approach for amplifying Raman signals.However,the simultaneous acquisition of nanostructured substrates with high enhancemen...Constructing surface-enhanced Raman scattering(SERS)substrates is a recognized and effective approach for amplifying Raman signals.However,the simultaneous acquisition of nanostructured substrates with high enhancement factors and repeatability poses challenges due to cost and technological limitations.Here,we developed nanometer-spaced metal gratings(NSMGs)with high sensitivity and uniformity for SERS applications by combining nanoimprint techniques with a flexible polydimethylsiloxane(PDMS)substrate.The grating spacing of NSMGs could be adjusted by capitalizing on the stretchability of PDMS,resulting in the acquisition of SERS gratings with different nano-sized gaps(minimum~22 nm)under a single imprinting mold with wide spacing.Importantly,the hotspots on the substrate can be flexibly tailored by the spacing adjustment,leading to the further enhancement of SERS signal,maximum up to nine-fold.Besides,the target molecule could be easily squeezed into the metal gaps with a strong localized electromagnetic field through active stretching and releasing of the substrate,which can further amplify the SERS signal.The high sensitivity and versatility of NSMGs were further proved by the label-free detection of rhodamine 6G(R6G)and adenine at nanomolar level.The proposed NSMG substrate is cost-effective and can be mass-produced,which has great potential for SERS applications.展开更多
基金Guangdong Introducing Innovative and Enterpreneurial Teams of“The Pearl River Talent Recruitment Program”(2019ZT08X340)Guangzhou Basic and Applied Basic Research Foundation(2023A04J2043)+1 种基金Basic and Applied Basic Research Foundation of Guangdong Province(2024A1515011728)National Natural Science Foundation of China(62275054,62175039)。
文摘Constructing surface-enhanced Raman scattering(SERS)substrates is a recognized and effective approach for amplifying Raman signals.However,the simultaneous acquisition of nanostructured substrates with high enhancement factors and repeatability poses challenges due to cost and technological limitations.Here,we developed nanometer-spaced metal gratings(NSMGs)with high sensitivity and uniformity for SERS applications by combining nanoimprint techniques with a flexible polydimethylsiloxane(PDMS)substrate.The grating spacing of NSMGs could be adjusted by capitalizing on the stretchability of PDMS,resulting in the acquisition of SERS gratings with different nano-sized gaps(minimum~22 nm)under a single imprinting mold with wide spacing.Importantly,the hotspots on the substrate can be flexibly tailored by the spacing adjustment,leading to the further enhancement of SERS signal,maximum up to nine-fold.Besides,the target molecule could be easily squeezed into the metal gaps with a strong localized electromagnetic field through active stretching and releasing of the substrate,which can further amplify the SERS signal.The high sensitivity and versatility of NSMGs were further proved by the label-free detection of rhodamine 6G(R6G)and adenine at nanomolar level.The proposed NSMG substrate is cost-effective and can be mass-produced,which has great potential for SERS applications.
