Graphene oxide-wrapped flower-like sliver particles for surface-enhanced Raman spectroscopy and their applications in polychlorinated biphenyls detection
“…After aging for 70 days, the signal intensities trended to be stable and the SERS intensity fell by 12.9% compared to the intensity of fresh Au/DW-45 substrate. This remarkable stability reveals that compared to Ag-based SERS substrates 41 , 42 , gold is an ideal material in SERS application for its resistance to oxidation and this result further indicates that the Au nanoisland and DW are steadily combined without abscission by DC magnetron sputtering technique. Figure 5 ( A ) SERS spectra of 10 −3 M detected on Au/DW-45 substrate with different periods; ( B ) Plot of Raman intensities of R6G at 610 cm −1 versus different detection time; ( C ) SERS spectra of 10 −6 M R6G obtained from 100 randomly selected spots on Au/DW-45 substrate; ( D ) the Raman mapping viewer (step size is 1 μm, 10 × 10 = 100 μm 2 ) after the target molecule of R6G dried on the Au/DW-45, here the brightness is proportional to the signal integral intensity centered at 1361 cm −1 .…”
A flexible and stable biomimetic SERS substrate was successfully fabricated by depositing gold (Au) nanoislands on the dragonfly wings (DW) via a simple DC magnetron sputtering system. Characterizations of the Au/DW nanostructure indicated that the optimum Au/DW-45 (sputtering time was 45 min) substrate owns high sensitivity, good stability and outstanding reproducibility. The limit of detection (LOD) for Rhodamine 6 G (R6G) was as low as 10−7 M and enhancement factor (EF) was calculated to be 2.8 × 106. 70-day-duration stability tests showed that Raman intensity of R6G reduced only by 12.9% after aging for 70 days. The maximum relative standard deviations (RSD) of SERS intensities from 100 positions of Au/DW-45 substrate were less than 8.3%, revealing outstanding uniformity and reproducibility. Moreover, the flexible Au/DW-45 bioscaffold arrays were employed to solve the vital problem of pesticide residues. By directly sampling from tomato peels via a “press and peel off” approach, cypermethrin has been rapidly and reliably determined with a LOD centered at 10−3 ng/cm2 and a correlation coefficient (R2) of 0.987. The positive results demonstrated that the Au-based DW biomimetic arrays may offer an efficient SERS platform for the identification of various pesticide residues on real samples.
“…After aging for 70 days, the signal intensities trended to be stable and the SERS intensity fell by 12.9% compared to the intensity of fresh Au/DW-45 substrate. This remarkable stability reveals that compared to Ag-based SERS substrates 41 , 42 , gold is an ideal material in SERS application for its resistance to oxidation and this result further indicates that the Au nanoisland and DW are steadily combined without abscission by DC magnetron sputtering technique. Figure 5 ( A ) SERS spectra of 10 −3 M detected on Au/DW-45 substrate with different periods; ( B ) Plot of Raman intensities of R6G at 610 cm −1 versus different detection time; ( C ) SERS spectra of 10 −6 M R6G obtained from 100 randomly selected spots on Au/DW-45 substrate; ( D ) the Raman mapping viewer (step size is 1 μm, 10 × 10 = 100 μm 2 ) after the target molecule of R6G dried on the Au/DW-45, here the brightness is proportional to the signal integral intensity centered at 1361 cm −1 .…”
A flexible and stable biomimetic SERS substrate was successfully fabricated by depositing gold (Au) nanoislands on the dragonfly wings (DW) via a simple DC magnetron sputtering system. Characterizations of the Au/DW nanostructure indicated that the optimum Au/DW-45 (sputtering time was 45 min) substrate owns high sensitivity, good stability and outstanding reproducibility. The limit of detection (LOD) for Rhodamine 6 G (R6G) was as low as 10−7 M and enhancement factor (EF) was calculated to be 2.8 × 106. 70-day-duration stability tests showed that Raman intensity of R6G reduced only by 12.9% after aging for 70 days. The maximum relative standard deviations (RSD) of SERS intensities from 100 positions of Au/DW-45 substrate were less than 8.3%, revealing outstanding uniformity and reproducibility. Moreover, the flexible Au/DW-45 bioscaffold arrays were employed to solve the vital problem of pesticide residues. By directly sampling from tomato peels via a “press and peel off” approach, cypermethrin has been rapidly and reliably determined with a LOD centered at 10−3 ng/cm2 and a correlation coefficient (R2) of 0.987. The positive results demonstrated that the Au-based DW biomimetic arrays may offer an efficient SERS platform for the identification of various pesticide residues on real samples.
“…Compared to other metal antibacterial materials, sliver nanoparticles (Ag NPs) exhibit an efficient antibacterial activity against a broad spectrum of bacteria including Escherichia coli (E.coli), Staphylococcus aureus (S.aures) and Candida albicans, thereby enjoying an extensive application in biomedical field. Surface coating of biomedical fibers with Ag NPs has been extensively studied in term of the utility in biomedical field [11][12][13][14][15][16][17]. Several methods can be used to make nanoparticle coatings on biomedical fabric, such as chemical deposition, spray pyrolysis, low plasma, and dip coating.…”
To prepare antibacterial fabrics with simple approach, wood pulp/viscose fibers and amino-capped silver nanoparticles (Ag NPs) solution were utilized to form Ag Nps-coated wetlace nonwove fabric. Characterization of the Ag Nps and prepared wetlace nonwoven fabric was performed in virtue of TEM, UV-vis, XRD, ICP-AES, FESEM, EDS mapping and antibacterial test. FESEM and EDS characterizations demonstrated the hierarchical and uniform coating of high-density Ag NPs on wood pulp fibers, and antibacterial test indicated the excellent antibacterial activity of prepared wetlace nonwoven fabric.
“…A higher density of nanoparticles leads to a stronger local plasmonic electric field and a stronger electromagnetic enhancement of Raman signal. However, the distance between the nanoparticles on the monolayer does not get infinitely smaller due to the electrostatic effect of the protectant that ensures a stable suspension of the nanoparticles. Thus, the nanoparticles reach equilibrium and are no longer close to each other.…”
This paper reports a “bottom‐up” substrate preparation method using a two‐phase interface self‐assembly technology that combines silver‐coated gold core–shell nanorods with the thermally shrinkable polystyrene (TSP) support material for surface‐enhanced Raman spectroscopy (SERS), that is, TSP‐SERS substrate. The gold nanorods with long absorption wavelength were used as the core, and the silver shells were coated to obtain the core–shell nanostructures with a stronger resonance with the wavelength of the light source. The density of the nanostructures and numbers of “hot spots” within the light spot increased via the three‐dimensional folding feature formed by thermal shrinkage. The combined effect of the two factors increases the enhancement factor by an order of magnitude to 107 after thermal contraction. The detection concentration of 4‐mercaptobenzoic acid can reach 10−9 M, and the maximum relative standard deviation is only 8.9%. In fact, the detection limit of benzimidazole on the surface of apple can reach 0.5 mg/L, and the recovery deviation is controlled within the range of 11.7%. The practical detection of benzimidazole pesticide residues showed that this method has wide application prospects in the detection of pesticide residues.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
