SERS polarization-dependent effects for an ordered 3D plasmonic tilted silver nanorod array

Abstract

Hexagonal close-packed tilted Ag nanorod arrays that exhibit excellent uniformity and reproducibility were prepared. The tilt angle was easily controlled by regulating the sputtering angle, accompanied by a reduction and constancy in the gap size of adjacent nanorods, which is 30° and 90° relative to the sputtering direction. The surface enhanced Raman spectroscopy (SERS) technique was used to characterize the interaction of tilted Ag nanorod arrays with polarized laser excitation. Interestingly, the SERS polarization-dependence increased with increasing tilt angle of the Ag nanorods. To elucidate the essential factors responsible for this SERS result, three-dimensional (3D) electromagnetic enhancement distribution for the proposed system was numerically simulated based on p- and s-polarization excitation. Most importantly, the fundamental reasons for the polarization dependence of SERS were obtained by a quantitative 3D numerical simulation of hotspot distribution for adjacent nanorods.

Manipulation and Applications of Hotspots in Nanostructured Surfaces and Thin Films

“…The detailed preparation process of large-scale ordered PS colloid sphere arrays is reported in our previous works [ 9 , 13 , 17 , 18 ]. Then, the size, nanogaps, and surface morphology of the as-prepared PS colloid sphere arrays is modified by physical and chemical method, which serves as a template [ 29 , 30 , 37 , 38 , 39 , 53 ]. Finally, various materials, including metal, metal oxides, polymers, and so on, are deposited on the ordered PS colloid sphere array templates by physical vapor deposition technique (for example, pulsed laser deposition, magnetron sputtering, thermal evaporation, e-beam evaporation), which make the nanostructured surfaces and thin films more functional.…”

“…The method is rapid, simple, low-cost, practical, and produces no pollution [ 13 ]. Various nanostructured surfaces and thin films can be achieved by the combination of NSL and physical vapor deposition, such as periodic nanocaps [ 14 , 15 , 16 , 17 , 18 ], nanotriangles [ 19 , 20 , 21 , 22 ], nanobowls [ 23 , 24 , 25 ], nanorings [ 26 , 27 , 28 ], nanopillars [ 29 , 30 ], nanocones [ 31 , 32 , 33 ], and other complex nanostructured surfaces and thin films, including nanohoneycomb, bridged knobby units, nanoparticle cluster-in-bowl arrays, and so on [ 2 , 25 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. These architectural designs of nanostructured surfaces and thin films can be obtained by controlling a series of deposition processes (the deposition time, angle, distance, and so on), PS colloid sphere etching, transfer, and their combination steps, which manipulate the formation, distribution, and evolution of hotspots and have significant implications in broad applications [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 …”

SERS Immunosensor of Array Units Surrounded by Particles: A Platform for Auxiliary Diagnosis of Hepatocellular Carcinoma

“…Because Raman spectroscopy provides fingerprint vibration information based on the composition, symmetry, and environment of a sample, it has been successfully used to measure the chemical composition [ 19 , 20 ], molecular structure, and other changes in the object to be tested [ 21 , 22 ]. Raman spectra can use light in the ultraviolet and near-infrared ranges as the source of excitation, which has positive significance for biological detection [ 23 , 24 ].…”

“…However, these studies mainly focused on the detection process of markers, and lack of exploration for the optimization of substrate structure performance, but the substrate with excellent performance was also crucial for detection. In previous studies, our research group has done a lot of research on the distribution of local surface plasmon resonance (LSPR) and hot spots by preparing nanospheres [ 35 ], nanobowls [ 36 ], nanorods [ 22 ], and others arrays structure, and was able to conclude that suitable plasmon coupling played a key role in improving SERS signal.…”

Controlling the 3D Electromagnetic Coupling in Co-Sputtered Ag–SiO2 Nanomace Arrays by Lateral Sizes

“…Metal nanostructures have been studied for decades, mainly due to their unique properties and wide applications in some fields, for example, catalysis, electronics, optics, information storage, biological sensors, and surface-enhanced Raman scattering (SERS) [ 1 , 2 , 3 , 4 ]. In particular, people use Au, Ag, and other noble metals because their surface plasmon resonance frequency are in the visible range of the electromagnetic spectrum.…”