Plasmon-Mediated Surface Engineering of Silver Nanowires for Surface-Enhanced Raman Scattering

Abstract

We reveal nanoscale morphological changes on the surface of a silver nanowire (AgNW) in the conventional surface-enhanced Raman scattering (SERS) measurement condition. The surface morphology changes are due to the surface plasmon-mediated photochemical etching of silver in the presence of certain Raman probes, resulting in a dramatic increase of Raman scattering intensity. This observation indicates that the measured SERS enhancement does not always originate from the as-designed/fabricated structures themselves, but sometimes with contribution from the morphological changes by plasmon-mediated photochemical reactions. Our work provides a guideline for more reliable SERS measurements and demonstrates a novel method for simple and site-specific engineering of SERS substrate and AgNW probes for designing and fabricating new SERS systems, stable and efficient TERS mapping, and single-cell SERS endoscopy.

Effect of nanostructured silicon on surface enhanced Raman scattering

“…The strong Raman band at 1142 cm À1 indicates a chemical conversion from PATP to 4,4 0 -dimercaptoazobenzene (DMAB) upon light irradiation. 11 As discussed, electromagnetic mechanism dominates the observed SERS enhancement. To conrm the role of silicon morphology, we did numerical simulation using the nitedifference time-domain (FDTD) method to investigate the localized electromagnetic eld distributions on AgNPs-coated at and nanoporous silicon surfaces.…”

“…[3][4][5][6][7][8][9] Metal materials are mainly employed in fabricating SERS structures, especially gold or silver ones for visible spectrum excitation. 10,11 To date, many nanostructures have been reported that can enhance Raman scattering enormously, leading to so called Raman hot spots, [12][13][14][15] including nanogaps, 16,17 nanostars, 18 nanotriangles and nanorods, 19 mainly due to the introduction of a localized electromagnetic eld under illumination. This kind of enhancement is referred to as the electromagnetic mechanism, which dominates the SERS enhancement in most cases.…”

Crack Formation on Crystalline Bismuth Oxychloride Thin Square Sheets by Using a Wet‐Chemical Method

“…Nanocrystals, especially semiconductor ones, usually possess unique chemical, electrical, optical and magnetic properties compared to their bulk counterparts . These properties are highly dependent on the chemical composition, size, shape and surface state of the nanocrystals . Therefore, controlled synthesis of nanocrystals is becoming a hot topic in many fields, and lots of efforts have been made to precisely control the morphology and surface state of the nanocrystals .…”

Silver Nanowire‐Templated Molecular Nanopatterning and Nanoparticle Assembly for Surface‐Enhanced Raman Scattering

“…[1][2][3] In these fields, it is of great importance to fabricate nanostructures, for both fundamental study and practical applications. [4,5] Nanolithography involves the precise fabrication and interconnection of structures on the nanometer scale, [6] using techniques such as photolithography [7,8] and e-beam lithography [9][10][11] (often combined with etching). These techniques are highly programmable and straightforward and have been used to realize many complexs tructures.…”

“…[20][21][22][23][24] Silver nanowires (AgNWs) are one of the most studied nanowires due to their promising mechanical, optical and electronic properties. Until now,A gNWsh ave been used as plasmonic waveguides, [25] surface-enhanced Ramans cattering (SERS) platforms, [4] for single-cell endoscopy, [26] as tip-enhanced spectroscopy probes, [27] etc. The polyol synthesized AgNWsp ossess well-definedf ive-fold twin structure and ap entagon-shaped cross section, and their physicochemical properties have been fully characterized by several research groups.…”