Surface-Enhanced Raman Scattering in Local Optical Fields of Silver and Gold NanoaggregatesFrom Single-Molecule Raman Spectroscopy to Ultrasensitive Probing in Live Cells

Kneipp, Katrin; Kneipp, Harald; Kneipp, Janina

doi:10.1021/ar050107x

Cited by 638 publications

(511 citation statements)

References 57 publications

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“…Among various metal nanoparticles, gold (Au) is the most widespread material used in optics, electrochemistry, catalysis, and biochemical sensing because it is stable, less toxic and biocompatible [1][2][3][4]. A lot of techniques have been developed for the synthesis of Au nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Facile green synthesis of gold nanoparticles with gum arabic as a stabilizing agent and reducing agent

Chen

2010

Gold Bull

100

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A facile, completely green, and cheap route for the synthesis of Au nanoparticles at 25-75°C has been developed by using only hydrogen tetrachloroaurate as the precursor and gum arabic (GA) simultaneously as a reducing agent and a stabilizing agent. No extra reagents are needed. From the analyses of UV/VIS absorption spectra, TEM, HRTEM, SAED, and XRD patterns, the formation of Au nanoparticles with a fcc structure was recognized. The synthesis reaction was usually finished in 2-4 h. Increasing the reaction temperature increased the formation rate but had no significant effect on the optical property and size of Au nanoparticles. With increasing Au(III) ion concentration or GA concentration, the mean diameter of Au nanoparticles slightly increased. Also, the particle size distribution became broader at higher Au(III) ion concentration or lower GA concentration due to the insufficient protection. Although raising the GA concentration was helpful to reduce Au(III) ions completely and stabilize the Au nanoparticles, too high GA concentration was not suitable for the stabilization of Au nanoparticles because the increased intermolecular force of GA might hinder the dispersion of Au nanoparticles. Furthermore, the resultant Au nanoparticles were found to remain highly stable in the NaCl solution.

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Section: Introductionmentioning

confidence: 99%

Facile green synthesis of gold nanoparticles with gum arabic as a stabilizing agent and reducing agent

Chen

2010

Gold Bull

100

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“…However, Ag is considered unstable, degrades in vivo and is typically synthesized with cetrimonium bromide (CTAB), which is considered cytotoxic [282][283][284]. Additionally, it has been demonstrated that the peak intensity ratios of the Raman signal change significantly when silver aggregates are used leading to inconsistent results and poor reproducibility [276,[285][286][287].…”

Section: Surface Enhanced Raman Scattering (Sers) and Electromagneticmentioning

confidence: 99%

“…They are considered to have many advantages over traditional enzyme linked immunosorbent assays (ELISAS) which are considered tedious, time consuming, and rely on the use of toxic and unstable fluorescent dyes and quantum dots (QDs) [282,[315][316][317]. It is known that SERS has equal or in some cases a greater enhancement of Raman signal when compared to fluorescent markers and that SERS metal substrates produce spectral line widths which are 10-100 times narrower compared to fluorescence [64,318,319].…”

Section: Sers Immunoassaysmentioning

confidence: 99%

Controllable Cobalt Oxide/Au Hierarchically Nanostructured Electrode for Nonenzymatic Glucose Sensing

2016

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By electrodeposition and galvanic replacement reaction, we developed a facile, time-saving, cost-effective, and environmentally friendly, two-step synthesis route to obtain a controllable cobalt oxide/Au hierarchically nanostructured electrode for glucose sensing. The nanomaterials were characterized by transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, energy-dispersive spectrometry, and X-ray photoelectron spectroscopy, meanwhile, the sensing performance was investigated by cyclic voltammetry and amperometric response. The results revealed that this novel electrode exhibited excellent electrocatalytic performance toward glucose oxidation, with a wide double-linear range from 0.2 μM to 20 mM and a low detection limit of 0.1 μM based on a signal-to-noise ratio of 3, which was mainly attributed to the ability of loading a small amount of Au with good electron conductivity on the surface of cobalt oxide nanosheets with large active surface area and synergistic electrocatalytic activity of Au and cobalt oxide toward glucose electrooxidation. This facile, sensitive, and selective glucose sensor is also proven to be suitable for the detection of glucose in human serum.

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“…51 From this equation, one could see the distances of the SERS substrate and reporters, the surface densities of the reporters, and the dispersing state of the tags, as a reviewer indicated. Experimental results revealed that the tag was monodispersed in each test condition.…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 99%

Phospholipid Encapsulated AuNR@Ag/Au Nanosphere SERS Tags with Environmental Stimulus Responsive Signal Property

Wang

et al. 2016

ACS Appl. Mater. Interfaces

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Surface-enhanced Raman scattering (SERS) tags draw much attention due to the ultrasensitivity and multiplex labeling capability. Recently, a new kind of SERS tags was rationally designed by encapsulating metal nanoparticles with phospholipid bilayers, showing great potential in theranostics. The lipid bilayer coating confers biocompatibility and versatility to changing surface chemistry of the tag; however, its "soft" feature may influence SERS signal stability, which is rarely investigated. Herein, we prepared phospholipidcoated AuNR@Ag/Au nanosphere SERS tags by using three different kinds of Raman reporters, i.e., thio-containing 4-nitrothiophenol (NT), nitrogen-containing hydrophobic chromophore cyanine 7 monoacid (Cy7), and alkyl chain− chromophore conjugate 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindodicarbocyanine (DiD). It was found that signal responses were different upon additional stimulation which the tags may encounter in theranostic applications including the presence of detergent Triton X-100, lipid membrane, and photothermal treatment. Living-cell imaging also showed signal changing distinction. The different SERS signal performances were attributed to the different Raman reporter releasing behaviors from the tags. This work revealed that Raman reporter structure determined signal stability of lipid-coated SERS tags, providing guidance for the design of stimulus responsive tags. Moreover, it also implied the potential of SERS technique for real time drug release study of lipid based nanomedicine.

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Surface-Enhanced Raman Scattering in Local Optical Fields of Silver and Gold NanoaggregatesFrom Single-Molecule Raman Spectroscopy to Ultrasensitive Probing in Live Cells

Cited by 638 publications

References 57 publications

Facile green synthesis of gold nanoparticles with gum arabic as a stabilizing agent and reducing agent

Facile green synthesis of gold nanoparticles with gum arabic as a stabilizing agent and reducing agent

Controllable Cobalt Oxide/Au Hierarchically Nanostructured Electrode for Nonenzymatic Glucose Sensing

Phospholipid Encapsulated AuNR@Ag/Au Nanosphere SERS Tags with Environmental Stimulus Responsive Signal Property

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