Robust, reproducible, recyclable SERS substrates: monolayers of gold nanostars grafted on glass and coated with a thin silica layer

Bassi, Barbara; Albini, Benedetta; D’Agostino, Agnese; Dacarro, Giacomo; Pallavicini, Piersandro; Galinetto, P.; Taglietti, Angelo

doi:10.1088/1361-6528/aae9b3

Cited by 30 publications

(27 citation statements)

References 59 publications

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“…We used the same laser wavelength and light power (632.8 nm and 1.5 × 10 5 W/cm 2 ), same integration times (20 s) and same objective magnification (50×). As already explained in our previous paper [17] to derive a reliable EF value it is important to evaluate the scattered volumes in the two experiments and considering that the SERS signal decreases dramatically with distance vanishing beyond 10–20 nm. In the present case the ratio between the scattering volumes in Raman and SERS experiments is approximately equal to 2 × 10 3 .…”

Section: Methodsmentioning

confidence: 99%

High Stability Thiol-Coated Gold Nanostars Monolayers with Photo-Thermal Antibacterial Activity and Wettability Control

et al. 2019

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The adhesion and proliferation of bacteria on abiotic surfaces pose challenges in both health care and industrial applications. Gold nanostars (GNSs) monolayers grafted on glass have demonstrated to exert antibacterial action due to their photo-thermal features. Here, these GNS layers were further functionalized using thiols monolayers, in order to impart different wettability to the surfaces and thus adding a feature that could help to fight bacterial proliferation. Thiol that has different functional groups was used and the thiol-protected surfaces were characterized by means of UV-vis spectroscopy, contact angles, SEM and surface enhanced Raman spectroscopy (SERS). We verified that (i) coating with the proper thiol allows us to impart high hydrophilicity or hydrophobicity to the surfaces (with contact angle values ranging from 10 to 120°); (ii) GNS monolayers are strongly stabilized by functionalization with thiols, with shelf stability increasing from a few weeks to more than three months and (iii) photo-thermal features and subsequent antibacterial effects caused by hyperthermia are not changed by thiols layers, allowing us to kill at least 99.99% of representative bacterial strains.

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Section: Methodsmentioning

confidence: 99%

High Stability Thiol-Coated Gold Nanostars Monolayers with Photo-Thermal Antibacterial Activity and Wettability Control

et al. 2019

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“…SERS as a technique for pesticide detection has been cited in several studies, and has shown promising results to be a rapid method that could even detect analytes at trace amounts. Several materials and morphologies have been explored with this particular application in mind—Ag nanoflowers [18], Au/Ag nanorods [14], and colloidal Au nanoparticles [19] among others, all of which showed capabilities of detecting low pesticide concentrations, down to 10 −10 M. However, aside from sensitivity, there are still more factors to consider in this particular application, such as the reproducibility of results and the capability of the substrates to detect multiple pesticides in real food matrices [20,21]. To address these issues, morphology control and material selection have been given emphasis, focusing on achieving large-scale uniformity in obtaining SERS measurements [22].…”

Section: Introductionmentioning

confidence: 99%

SERS-Active Substrate with Collective Amplification Design for Trace Analysis of Pesticides

et al. 2019

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Health risks posed by the exposure to trace amounts of pesticide residue in agricultural products have gained a lot of concerns, due to their neurotoxic nature. The applications of surface-enhanced Raman Scattering (SERS) as a detection technique have consistently shown its potential as a rapid and sensitive means with minimal sample preparation. In this study, gold nanoparticles (Au NPs) in elliptical shapes were collected into a layer of ordered zirconia concave pores. The porous zirconia layer (pZrO2) was then deposited with Au NPs, denoted as Au NPs (x)/pZrO2, where x indicates the deposition thickness of Au NPs in nm. In the concave structure of pZrO2, Au-ZrO2 and Au-Au interactions provide a synergistic and physical mechanism of SERS, which is anticipated to collect and amplify SERS signals and thereafter improve the enhancement factor (EF) of Au NPs/pZrO2. By taking Rhodamine 6G (R6G) as the test molecule, EF of Au NPs/pZrO2 might reach to 7.0 × 107. Au NPs (3.0)/pZrO2 was then optimized and competent to detect pesticides, e.g., phosmet and carbaryl at very low concentrations, corresponding to the maximum residue limits of each, i.e., 0.3 ppm and 0.2 ppm, respectively. Au NPs (3.0)/pZrO2 also showed the effectiveness of distinguishing between phosmet and carbaryl under mixed conditions. Due to the strong affinities of the phosphoric groups and sulfur in phosmet to the Au NPs (3.0)/pZrO2, the substrate exhibited selective detection to this particular pesticide. In this study, Au NPs (3.0)/pZrO2 has thus demonstrated trace detection of residual pesticides, due to the substrate design that intended to provide collective amplification of SERS.

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“…To overcome the shortage, some reproducible preparations of clean and highly Ag and Au SERS active substrates have been reported in Reference [14]. Bassi et al [15] prepared recyclable SERS active glass chips. The gold nanostars were grafted on functionalized glasses by means of electrostatic interactions and then they were coated with a silica layer of controllable thickness.…”

Section: Introductionmentioning

confidence: 99%

Doped N/Ag Carbon Dot Catalytic Amplification SERS Strategy for Acetamiprid Coupled Aptamer with 3,3′-Dimethylbiphenyl-4,4′-diamine Oxidizing Reaction

Feng

Liang

et al. 2019

Nanomaterials

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The as-prepared co-doped N/Ag carbon dot (CDNAg) has strong catalysis of H2O2 oxidation of 3,3′-dimethylbiphenyl-4,4′-diamine (DBD). It forms an oxidation product (DBDox) with surface-enhanced Raman scattering (SERS) activity at 1605 cm−1 in the silver nanosol substrate, and a CDNAg catalytic amplification with SERS analytical platform can be structured based on aptamer (Apt) with the DBD oxidizing reaction. For example, the aptamer (Apt) of acetamiprid (ACT) can be adsorbed on the surface of CDNAg, resulting in inhibited catalytic activity, the reduced generation of DBDox, and a weakened SERS intensity. When the target molecule ACT was added, it formed a stable Apt-ACT complex and free CDNAg that restored catalytic activity and linearly enhanced the SERS signal. Based on this, we proposed a new quantitative SERS analysis method for the determination of 0.01–1.5 μg ACT with a detection limit of 0.006 μg/L.

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Robust, reproducible, recyclable SERS substrates: monolayers of gold nanostars grafted on glass and coated with a thin silica layer

Cited by 30 publications

References 59 publications

High Stability Thiol-Coated Gold Nanostars Monolayers with Photo-Thermal Antibacterial Activity and Wettability Control

High Stability Thiol-Coated Gold Nanostars Monolayers with Photo-Thermal Antibacterial Activity and Wettability Control

SERS-Active Substrate with Collective Amplification Design for Trace Analysis of Pesticides

Doped N/Ag Carbon Dot Catalytic Amplification SERS Strategy for Acetamiprid Coupled Aptamer with 3,3′-Dimethylbiphenyl-4,4′-diamine Oxidizing Reaction

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