Abstract:A simple and cost-effective strategy
was rationally designed to
fabricate a special sandwich structure consisting of graphene, bilayer
silver, and a copper plate, which was used as a surface-enhanced Raman
scattering (SERS) substrate for highly efficient SERS sensing and
detection of trace molecules. Silver dendrite (AgD) nanostructures
were subsequently grown on a silver nanosphere (AgNS)/Cu surface to
form a bilayer silver/Cu structure, which showed a 1.5-fold Raman
enhancement compared to that of the AgNS/C… Show more
“…For the peak at 1360 cm −1 , the loss of Raman signals of Rh6G is about 5.3% and 11%, respectively. Combined with previous reports [38, 39], it can be considered that the current GNR vertical arrays have good stability. Combine these advantages mentioned above, this substrate possesses great potential in sensing and detection.Fig.…”
The unique photonic effect of self-assembled metal nanoparticles is widely used in many applications. In this article, we prepared self-assembled gold nanorod (GNR) vertical arrays substrate by an evaporation method and found that the morphology of the substrate can be effectively regulated by changing the immersion time in the target molecules solution to obtain different Raman enhancement effects. We separately calculated the local electromagnetic field of the GNR vertical arrays and disorder substrate by the finite element method (FEM), which was consistent with the experimental results. Based on optimal soaking time, the sensitivity, reproducibility, and stability of substrates were separately studied. The experimental results show that the GNR vertical arrays can detect Rhodamine 6G (Rh6G) at concentrations as low as 10
−11
M and exhibit good reproducibility and stability due to local electromagnetic (EM) field enhancement caused by the coupling of adjacent nanorods. Thus, our work can demonstrate that the substrate has excellent surface-enhanced Raman scattering (SERS) activity and the obtained GNR vertical arrays have great potential for biosensor and biodetection.
“…For the peak at 1360 cm −1 , the loss of Raman signals of Rh6G is about 5.3% and 11%, respectively. Combined with previous reports [38, 39], it can be considered that the current GNR vertical arrays have good stability. Combine these advantages mentioned above, this substrate possesses great potential in sensing and detection.Fig.…”
The unique photonic effect of self-assembled metal nanoparticles is widely used in many applications. In this article, we prepared self-assembled gold nanorod (GNR) vertical arrays substrate by an evaporation method and found that the morphology of the substrate can be effectively regulated by changing the immersion time in the target molecules solution to obtain different Raman enhancement effects. We separately calculated the local electromagnetic field of the GNR vertical arrays and disorder substrate by the finite element method (FEM), which was consistent with the experimental results. Based on optimal soaking time, the sensitivity, reproducibility, and stability of substrates were separately studied. The experimental results show that the GNR vertical arrays can detect Rhodamine 6G (Rh6G) at concentrations as low as 10
−11
M and exhibit good reproducibility and stability due to local electromagnetic (EM) field enhancement caused by the coupling of adjacent nanorods. Thus, our work can demonstrate that the substrate has excellent surface-enhanced Raman scattering (SERS) activity and the obtained GNR vertical arrays have great potential for biosensor and biodetection.
“…To better understand the minimum concentration of R6G that can be tracked using our prepared SERS-active substrate, the lower detection limits of R6G reported using other copper-based SERS substrates are listed and compared in Table S1 of the Supporting Information. It is worth mentioning that, in this work, the minimum detection limit reached by the prepared SERS-active substrate is far superior to those reports in most literature. − Thus, the SERS-active substrate designed by us has an outstanding sensitivity. The commonly used analytical enhancement factors (AEF) are calculated for the SERS-1 substrate, and the specific calculation process is provided in the Supporting Information.…”
Section: Resultsmentioning
confidence: 62%
“…However, Raman characteristic peaks of the R6G dye molecule are observed on SERS-0.2, SERS-0.5, SERS-1, SERS-2, and SERS-3 substrates. According to the literature, [1][2][3][4][5][6][7][8][9][10][11][12][13][14]38 the bands of 1183, 1363, 1510, 1571, and 1650 cm −1 are the C-C stretching vibration of aromatic benzene rings; moreover, the peaks of 613 and 771 cm −1 are assigned to the C-H in-plane and out-of-plane bending vibration in the xanthene skeleton. As shown in Figure 5a, the R6G is detected on SERS-0.2 and SERS-0.5, but Raman peaks' intensities are much weaker, and the maximum Raman spectral intensity of R6G is obtained on SERS-1.…”
Section: ■ Results and Discussionmentioning
confidence: 98%
“…1−14 There are two universally accepted mechanisms regarding the enhancement effects of SERS, defined as the electromagnetic (EM) enhancement and the chemical (CHEM) mechanism. 1,4,9,10,13,15 The EM enhancement is related to the localized surface plasmon resonances (SPRs) excited by the incident light on the surface of rough metal substrates, and inelastic light scattering absorbed by noble metal nanoparticles is greatly enhanced. On the contrary, the CHEM mechanism is mainly attributed to the electron transfer between the molecules to be tested and the SERS-active matrix, the so-called charge-transfer mechanism.…”
Section: ■ Introductionmentioning
confidence: 99%
“…Over the past few decades, the surface-enhanced Raman spectroscopy (SERS) possesses many advantages, such as fast, convenient, nondestructive testing, and low water interference, which has become an important and powerful analytical technique in various fields, including microanalytical applications, catalysis, electrochemistry, and environmental science. − There are two universally accepted mechanisms regarding the enhancement effects of SERS, defined as the electromagnetic (EM) enhancement and the chemical (CHEM) mechanism. ,,,,, The EM enhancement is related to the localized surface plasmon resonances (SPRs) excited by the incident light on the surface of rough metal substrates, and inelastic light scattering absorbed by noble metal nanoparticles is greatly enhanced. On the contrary, the CHEM mechanism is mainly attributed to the electron transfer between the molecules to be tested and the SERS-active matrix, the so-called charge-transfer mechanism.…”
A simple, low-cost, and reliable strategy was developed to prepare SERS substrates with ultra-high sensitivity using laser-induced selective metallization of polymers combined with an improved galvanic replacement reaction. To verify the SERS activity, organic analytes, such as Rhodamine 6G (R6G), crystal violet (CV), and methylene blue (MB), were selected as the probe molecules. Surprisingly, the detection limit of R6G reached as low as 1 × 10 −17 M in SERS tests with the excitation wavelength of 532 nm, which was superior to the data reported in most literature, indicating an ultra-high SERS sensitivity. XPS, WAXD, SEM, and EDS revealed that evenly distributed nanoparticles with 203 nm based on the Cu-Ag alloy were successfully formed on the Cu layer of the polymer. Besides, the RSD values of the main characteristic peaks of R6G were less than 0.20, showing a good reproducibility of the prepared SERS substrate. This SERS substrate also demonstrated good stability because it still kept a high SERS sensitivity after 35 days of air storage. Moreover, this new substrate showed the potential for reuse and probably addressed the problem that the traditional SERS substrate can only be used once. We believe this facile and reliable approach to preparing a new SERS substrate will have prospects for large-scale production and applications in the field of analytics.
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