Enzyme-amplified SERS immunoassay with Ag-Au bimetallic SERS hot spots

Pham, Xuan‐Hung; Hahm, Eunil; Kim, Tae Han; Kim, Hyung Mo; Lee, Sang Hun; Lee, Sang Chul; Kang, Homan; Lee, Ho‐Young; Jeong, Dae Hong; Choi, Hak

doi:10.1007/s12274-020-3014-3

Cited by 65 publications

(32 citation statements)

References 62 publications

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“…For Raman measurement, the concentration of SERS substrate is one of the most important factors affecting the SERS signal [ 39 , 41 , 44 ]. Figure 4 d and Figure S7 showed the effect of SiO 2 @Au@Ag@4-MPBA concentration after glucose incubation in the presence of GOx on the SERS signal of 4-MPBA.…”

Section: Resultsmentioning

confidence: 99%

“…The presence of the silica template facilitates the density, size, and shape, and the nanogap of Au-Au on the SiO 2 surface was easily controlled by SiO 2 core, and generating a homogenous SERS substrate of SiO 2 @Au@Ag [ 39 ]. As a result, a high-strength and reliable SiO 2 @Au@Ag based-SERS substrates with high reproducibility and 4.2 × 10 6 fold-enhancement as compared to without the nanomaterial was developed for the enzyme-linked immunosorbent assay (ELISA) [ 40 , 41 ]. Simultaneously, a Raman reporter was also immobilized between the Au and Ag layer to play the role of an internal standard for the accurate detection of the pesticide thiram [ 42 , 43 , 44 ].…”

Section: Introductionmentioning

confidence: 99%

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Glucose Detection of 4-Mercaptophenylboronic Acid-Immobilized Gold-Silver Core-Shell Assembled Silica Nanostructure by Surface Enhanced Raman Scattering

et al. 2021

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The importance of glucose in many biological processes continues to garner increasing research interest in the design and development of efficient biotechnology for the sensitive and selective monitoring of glucose. Here we report on a surface-enhanced Raman scattering (SERS) detection of 4-mercaptophenyl boronic acid (4-MPBA)-immobilized gold-silver core-shell assembled silica nanostructure (SiO2@Au@Ag@4-MPBA) for quantitative, selective detection of glucose in physiologically relevant concentration. This work confirmed that 4-MPBA converted to 4-mercaptophenol (4-MPhOH) in the presence of H2O2. In addition, a calibration curve for H2O2 detection of 0.3 µg/mL was successfully detected in the range of 1.0 to 1000 µg/mL. Moreover, the SiO2@Au@Ag@4-MPBA for glucose detection was developed in the presence of glucose oxidase (GOx) at the optimized condition of 100 µg/mL GOx with 1-h incubation time using 20 µg/mL SiO2@Au@Ag@4-MPBA and measuring Raman signal at 67 µg/mL SiO2@Au@Ag. At the optimized condition, the calibration curve in the range of 0.5 to 8.0 mM was successfully developed with an LOD of 0.15 mM. Based on those strategies, the SERS detection of glucose can be achieved in the physiologically relevant concentration range and opened a great promise to develop a SERS-based biosensor for a variety of biomedicine applications.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Glucose Detection of 4-Mercaptophenylboronic Acid-Immobilized Gold-Silver Core-Shell Assembled Silica Nanostructure by Surface Enhanced Raman Scattering

et al. 2021

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“…The density of the Au NPs and the gaps between two Au NPs on the surface of SiO 2 can be tunable and provide a stronger localized surface plasmon resonance (LSPR) property. As a result, SiO 2 @Au–Ag can be developed as high-strength and reliable SERS substrates for the enzyme-linked immunosorbent assay (ELISA) [ 37 , 38 ], which is an internal SERS [ 34 , 35 ], pesticide detection standard [ 39 ], and provides detection of toxic chemical compound in pharmaceutics [ 40 ]. However, the cellular toxicity and easy oxidation of intrinsic Ag of our nanostructure limits their application in vivo [ 41 , 42 ].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Densely Immobilized Gold-Assembled Silica Nanostructures

Seong

Bock

Hahm

et al. 2021

IJMS

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In this study, dense gold-assembled SiO2 nanostructure (SiO2@Au) was successfully developed using the Au seed-mediated growth. First, SiO2 (150 nm) was prepared, modified by amino groups, and incubated by gold nanoparticles (ca. 3 nm Au metal nanoparticles (NPs)) to immobilize Au NPs to SiO2 surface. Then, Au NPs were grown on the prepared SiO2@Au seed by reducing chloroauric acid (HAuCl4) by ascorbic acid (AA) in the presence of polyvinylpyrrolidone (PVP). The presence of bigger (ca. 20 nm) Au NPs on the SiO2 surface was confirmed by transmittance electronic microscopy (TEM) images, color changes to dark blue, and UV-vis spectra broadening in the range of 450 to 750 nm. The SiO2@Au nanostructure showed several advantages compared to the hydrofluoric acid (HF)-treated SiO2@Au, such as easy separation, surface modification stability by 11-mercaptopundecanoic acid (R-COOH), 11-mercapto-1-undecanol (R-OH), and 1-undecanethiol (R-CH3), and a better peroxidase-like catalysis activity for 5,5′-Tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) reaction. The catalytic activity of SiO2@Au was two times better than that of HF-treated SiO2@Au. When SiO2@Au nanostructure was used as a surface enhanced Raman scattering (SERS) substrate, the signal of 4-aminophenol (4-ATP) on the surface of SiO2@Au was also stronger than that of HF-treated SiO2@Au. This study provides a potential method for nanoparticle preparation which can be replaced for Au NPs in further research and development.

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“…Based on these advantages of Au-Ag alloy NPs, our group recently reported nanostructures with Au-Ag NPs clustered on a silica core [31][32][33]. These nanostructures had a single broad absorbance peak, and the formation of optimized Au-Ag alloy NPs showed distinct colors depending on the target concentration [34,35].Accordingly, in this study, we developed an LFIA platform using Au-Ag alloy NPs assembled on silica NPs (SiO 2 @Au-Ag NPs) for the visual analysis of PSA. SiO 2 @Au-Ag NPs were synthesized using an optimized synthesis method.…”

Section: Introductionmentioning

confidence: 99%

Au–Ag assembled on silica nanoprobes for visual semiquantitative detection of prostate-specific antigen

Kim

et al. 2021

J Nanobiotechnol

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Background Blood prostate-specific antigen (PSA) levels are widely used as diagnostic biomarkers for prostate cancer. Lateral-flow immunoassay (LFIA)-based PSA detection can overcome the limitations associated with other methods. LFIAbased PSA detection in clinical samples enables prognosis and early diagnosis owing to the use of high-performance signal reporters. Results Here, a semiquantitative LFIA platform for PSA detection in blood was developed using Au–Ag nanoparticles (NPs) assembled on silica NPs (SiO2@Au–Ag NPs) that served as signal reporters. Synthesized SiO2@Au–Ag NPs exhibited a high absorbance at a wide wavelength range (400–800 nm), with a high scattering on nitrocellulose membrane test strips. In LFIA, the color intensity of the test line on the test strip differed depending on the PSA concentration (0.30–10.00 ng/mL), and bands for the test line on the test strip could be used as a standard. When clinical samples were assessed using this LFIA, a visual test line with particular color intensity observed on the test strip enabled the early diagnosis and prognosis of patients with prostate cancer based on PSA detection. In addition, the relative standard deviation of reproducibility was 1.41%, indicating high reproducibility, and the signal reporter showed good stability for 10 days. Conclusion These characteristics of the signal reporter demonstrated the reliability of the LFIA platform for PSA detection, suggesting potential applications in clinical sample analysis.

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Enzyme-amplified SERS immunoassay with Ag-Au bimetallic SERS hot spots

Cited by 65 publications

References 62 publications

Glucose Detection of 4-Mercaptophenylboronic Acid-Immobilized Gold-Silver Core-Shell Assembled Silica Nanostructure by Surface Enhanced Raman Scattering

Glucose Detection of 4-Mercaptophenylboronic Acid-Immobilized Gold-Silver Core-Shell Assembled Silica Nanostructure by Surface Enhanced Raman Scattering

Synthesis of Densely Immobilized Gold-Assembled Silica Nanostructures

Au–Ag assembled on silica nanoprobes for visual semiquantitative detection of prostate-specific antigen

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