Design of Armrest Ag Nanorod Arrays with High SERS Performance for Sensitive Biomolecule Detection

Abstract

To enlarge the surface-enhanced Raman scattering (SERS) enhancement of Ag nanopillar arrays, a well-controlled armrest Ag NRs@Al2O3 structure was designed, aiming at triggering efficient resonance between the nanopillar and the Ag NRs. A series of armrest Ag NRs@Al2O3 with well-designed morphology as well as enhanced “hot spots” quantity by taking advantage of AAO template and oblique angle deposition were successfully fabricated. Both experimental results and numerical simulations revealed localized surface plasmon resonance (LSPR) tunability by simply optimizing the arm length. An optimal substrate with outstanding SERS performance for dyes and biomolecular was realized by enhancing the hot spots area while tuning the resonance peak close to the 785 nm excitation. The as-fabricated 14-Ag NRs@Al2O3 without any surface modification presented a glucose detection limit of 1 × 10–4 mM, endowing our SERS platform for sensitive label-free biodetection.

Preparation of CuO nanosheet array thin film with controlled morphology for SERS and photocatalysis

“…[1][2][3][4][5][6] The conventional SERSactive substrates are mostly based on noble metals, offering key advantages in terms of ultrahigh sensitivity. 7,8 However, due to limited noble metal resources, high price and some drawbacks in chemical stability, there are still many challenges in their practical application. 9,10 In comparison to metals, semiconductors are considered as complementary materials for SERS, offering crucial advantages of versatility, reproducibility, and recyclability.…”

“…1–6 The conventional SERS-active substrates are mostly based on noble metals, offering key advantages in terms of ultrahigh sensitivity. 7,8 However, due to limited noble metal resources, high price and some drawbacks in chemical stability, there are still many challenges in their practical application. 9,10…”

Glucose sandwich assay based on surface-enhanced Raman spectroscopy

“…Many studies have been conducted on the detection of glucose using SERS. [24][25][26] Zhang et al 27 proposed an innovative Ag nanorods@Al 2 O 3 structure SERS substrates capable of detecting glucose at concentrations as low as 0.1 mM using SERS by increasing hot spots and tuning resonance between Ag nanopillars and Ag nanorods. However, glucose naturally emits weak Raman signals due to its small Raman scattering cross-section, measuring only 5.6 × 10 −30 cm 2 per molecule per steradian, which is approximately 14 orders of magnitude smaller than its fluorescence, and glucose's Raman emission is easily obscured by strong background noises from the surrounding environment, limiting glucose detection sensitivity and selectivity.…”

Gold Nanocolumnar Templates for Effective Chemical Sensing by Surface-Enhanced Raman Scattering

“…Such nanocolumnar films are of special interest for SERS due to the confinement and enhancement of the electric field within the nanogaps between neighboring nanocolumns [ 36 ]. Various works also used the GLAD or OAD techniques sometimes coupled to other techniques for the fabrication of SERS templates with a plethora of nanosystem geometries such as tilted silver nanorods, armrest Ag nanorods, gold trimers and dimers, metal–insulator–metal nanoparticles, and Ag@Au nanorods, achieving enhancement factors (EFs) of 8 × 10 to 10 [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. In addition, a large number of research groups have already investigated thiophenol detection by SERS, reaching EFs of 10 to 10 , and using other manufacturing technologies of plasmonic nanosystems [ 45 , 46 , 47 ].…”