Highly Sensitive and Reproducible SERS Substrates Based on Ordered Micropyramid Array and Silver Nanoparticles

Abstract

The construction of a highly sensitive and reproducible surface-enhanced Raman scattering (SERS) substrate is the key factor that restricts its practical application. In this paper, a three-dimensional (3D) SERS substrate based on ordered micropyramid array and silver nanoparticles (MPA/AgNPs 3D-SERS) was constructed using the roll-to-plate embossing technology and a hydrothermal method, which provided an efficient and low-cost preparation process for the SERS substrate. Using rhodamine 6G (R6G) as a probe molecule, the performance of an MPA/AgNP 3D-SERS substrate was studied in detail, whose minimum detection limit was 10–12 M and the enhancement factor was calculated as 8.8 × 109, indicating its high sensitivity. In addition, the minimum relative standard deviation (RSD) for the MPA/AgNP 3D-SERS substrate was calculated as 4.99%, and SERS performance basically had no loss after 12 days of placement, which indicated that the prepared SERS substrate had excellent stability and repeatability. At last, the thiram detection application of the MPA/AgNP 3D-SERS substrate was also investigated. The results showed that the minimum detection limit was 1 × 10–7 M, and quantitative analysis of pesticide residues could be realized. This research could provide useful guidance for the efficient and low-cost fabrication of highly sensitive and reproducible SERS substrates.

Raman Scattering-Based Biosensing: New Prospects and Opportunities

“…First, the main problem is in measuring Raman spectra and applying this method for the quantitative analysis of a substance is associated with the inhomogeneous distribution of “hot spots” on the surface of the substrate, which contributes to significant changes in the reproducibility of the SERS signal. This problem of the preparation of SERS-active substrates is described by many authors who offer their solutions [ 218 , 219 , 220 ]; however, it has not yet been possible to develop a fundamentally new scheme for the fabrication of nanocomposite materials with the ideally uniform distribution of hot spots. Moreover, much attention needs to be paid to the study of a wider range of molecules of different origins, which find their application in life science [ 221 ].…”

Reproducible Flexible SERS Substrates Inspired by Bionic Micro‐Nano Hierarchical Structures of Rose Petals

“…The Surface‐enhancement Raman scattering (SERS) has developed rapidly in recent years, [ 1–3 ] which could significantly enlarge the signal of conventional Raman test, achieve trace detection, and even single‐molecule detection. [ 4 ] Because of its unique fingerprint peak characteristics, non‐destructive testing, fast response, and other advantages, [ 5,6 ] it is widely used in environmental monitoring, [ 7,8 ] food safety, [ 9–11 ] biomedicine, and other fields. [ 12–14 ]…”

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enlarge the signal of conventional Raman test, achieve trace detection, and even single-molecule detection. [4] Because of its unique fingerprint peak characteristics, non-destructive testing, fast response, and other advantages, [5,6] it is widely used in environmental monitoring, [7,8] food safety, [9][10][11] biomedicine, and other fields. [12][13][14] So far, there is no clear theoretical model that can explain the complex SERS phenomenon.However, electromagnetic enhancement (EM) and chemical enhancement (CM) are two kinds of SERS mechanisms that are generally accepted by the academic community.

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FDTD Analysis of Hotspot-Enabling Hybrid Nanohole-Nanoparticle Structures for SERS Detection

“…Metallic nanoparticles (MNPs), in particular, are commonly used to create SERS-active substrates due to their confined localized SPR (LSPR) upon wavelength-specific light excitation [ 16 ]. Despite the multiple advantages offered by MNP-based SERS substrates, including their low cost and ease of fabrication, reproducibility still remains a challenge [ 17 , 18 ]. The nanoplasmonic capabilities of nanohole arrays (NHAs) have been theoretically predicted and demonstrated through FDTD simulations [ 19 , 20 ] and experimentation [ 3 , 21 ].…”