Graphene and Graphene Oxide Applications for SERS Sensing and Imaging

: Surface Enhanced Raman Spectroscopy (SERS) has a long history as an ultrasensitive platform for the detection of biological species from small aromatic molecules to complex biological systems as circulating tumor cells. Thanks to unique properties of graphene, the range of SERS applications has largely expanded. Graphene is efficient fluorescence quencher improving quality of Raman spectra. It contributes also to the SERS enhancement factor through the chemical mechanism. In turn, the chemical flexibility of Reduced Graphene Oxide (RGO) enables tunable adsorption of molecules or cells on SERS active surfaces. Graphene oxide composites with SERS active nanoparticles have been also applied for Raman imaging of cells. This review presents a survey of SERS assays employing graphene or RGO emphasizing the improvement of SERS enhancement brought by graphene or RGO. The structure and physical properties of graphene and RGO will be discussed too.

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Silver–Graphene Oxide Nanohybrids for Highly Sensitive, Stable SERS Platforms

Frontiers in Chemistry ◽

10.3389/fchem.2021.665205 ◽

2021 ◽

Vol 9 ◽

Author(s):

Mateusz Kasztelan ◽

Anna Studzinska ◽

Grażyna Zofia Żukowska ◽

Barbara Pałys

Keyword(s):

Raman Spectroscopy ◽

Ascorbic Acid ◽

Graphene Oxide ◽

Silver Nanoparticle ◽

Surface Composition ◽

Surface Enhanced Raman Spectroscopy ◽

Ammonia Solution ◽

Synthesis Conditions ◽

Sers Enhancement ◽

Surface Enhanced Raman

Graphene oxide–silver nanoparticle nanohybrids were synthesized by simple reduction of the silver nitrate and graphene oxide (GO) mixture in water using the mild reducing agent ascorbic acid. The concentration of ascorbic acid was varied to verify the possible influence of the GO surface composition on the efficiency of the hybrid material as substrates for surface enhanced Raman spectroscopy (SERS). Furthermore, the composites were conditioned in ammonia solution or in potassium hydroxide diluted solution. For comparison, the graphene oxide–silver nanoparticle composite has been synthesized using the ammonia-treated GO. All materials were characterized using spectroscopic and microscopic methods including UV–Vis, infrared, and Raman spectroscopy and scanning electron microscopy. The SERS efficiency of the nanohybrids was tested using 4-aminothiophenol (PATP). The optimal synthesis conditions were found. Ammonia and potassium peroxide drop-casted on the composite changed the SERS properties. The sample treated with KOH showed the best SERS enhancement. The variation of the SERS enhancement was correlated with the shape of the UV–Vis characteristics and the surface structure of the composites.

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Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.7.2 ◽

2016 ◽

Vol 7 ◽

pp. 9-21 ◽

Cited By ~ 11

Author(s):

Martina Banchelli ◽

Bruno Tiribilli ◽

Roberto Pini ◽

Luigi Dei ◽

Paolo Matteini ◽

...

Keyword(s):

Graphene Oxide ◽

Substrate Surface ◽

Surface Enhanced Raman Spectroscopy ◽

Silver Nanostructures ◽

Langmuir Blodgett ◽

Sers Enhancement ◽

Surface Areas ◽

Silver Nanocubes ◽

Surface Enhanced Raman ◽

Langmuir Blodgett Films

Hybrid graphene oxide/silver nanocubes (GO/AgNCs) arrays for surface-enhanced Raman spectroscopy (SERS) applications were prepared by means of two procedures differing for the method used in the assembly of the silver nanocubes onto the surface: Langmuir–Blodgett (LB) transfer and direct sequential physisorption of silver nanocubes (AgNCs). Adsorption of graphene oxide (GO) flakes on the AgNC assemblies obtained with both procedures was monitored by quartz crystal microbalance (QCM) technique as a function of GO bulk concentration. The experiment provided values of the adsorbed GO mass on the AgNC array and the GO saturation limit as well as the thickness and the viscoelastic properties of the GO film. Atomic force microscopy (AFM) measurements of the resulting samples revealed that a similar surface coverage was achieved with both procedures but with a different distribution of silver nanoparticles. In the GO covered LB film, the AgNC distribution is characterized by densely packed regions alternating with empty surface areas. On the other hand, AgNCs are more homogeneously dispersed over the entire sensor surface when the nanocubes spontaneously adsorb from solution. In this case, the assembly results in less-packed silver nanostructures with higher inter-cube distance. For the two assembled substrates, AFM of silver nanocubes layers fully covered with GO revealed the presence of a homogeneous, flexible and smooth GO sheet folding over the silver nanocubes and extending onto the bare surface. Preliminary SERS experiments on adenine showed a higher SERS enhancement factor for GO on Langmuir–Blodgett films of AgNCs with respect to bare AgNC systems. Conversely, poor SERS enhancement for adenine resulted for GO-covered AgNCs obtained by spontaneous adsorption. This indicated that the assembly and packing of AgNCs obtained in this way, although more homogeneous over the substrate surface, is not as effective for SERS analysis.

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Synthesis of bifunctional reduced graphene oxide/CuS/Au composite nanosheets for in situ monitoring of a peroxidase-like catalytic reaction by surface-enhanced Raman spectroscopy

RSC Advances ◽

10.1039/c6ra09471f ◽

2016 ◽

Vol 6 (59) ◽

pp. 54456-54462 ◽

Cited By ~ 28

Author(s):

Wei Song ◽

Guangdi Nie ◽

Wei Ji ◽

Yanzhou Jiang ◽

Xiaofeng Lu ◽

...

Keyword(s):

Raman Spectroscopy ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Catalytic Reaction ◽

Surface Enhanced Raman Spectroscopy ◽

In Situ Monitoring ◽

Reduced Graphene ◽

Surface Enhanced ◽

Surface Enhanced Raman

In this work, we have demonstrated the synthesis of bifunctional reduced graphene oxide/CuS/Au composite nanosheets for in situ monitoring of peroxidase-like catalytic reaction by surface-enhanced Raman spectroscopy.

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