First‐Layer Effect in Graphene‐Enhanced Raman Scattering

Graphene as a substrate for enhancing Raman scattering, called graphene‐enhanced Raman scattering (GERS), has been reported in previous work. Herein, it is found that the “first‐layer effect”, which is widely used to explain the chemical‐enhanced mechanism in surface‐enhanced Raman scattering (SERS), exists in the GERS system. The Langmuir–Blodgett (LB) technique is used to construct mono‐ and multilayer ordered aggregates of protoporphyrin IX (PPP). Raman spectra of PPP with different layer numbers of the LB film on graphene are collected. The Raman signal from the first monolayer LB film of PPP has a larger contribution to the Raman enhancement than that from subsequent monolayers. Meanwhile, the Raman enhancement is dependent on the molecular configuration in contact with graphene, in which the functional group of PPP in direct contact with graphene has a stronger enhancement than other groups. These results reveal that GERS is strongly dependent on the distance between graphene and the molecule, which is convincing evidence that the Raman enhancement effect based on graphene belongs to the chemical‐enhanced mechanism. This discovery provides a convenient system for the study of the chemical‐enhanced mechanism and will benefit further understanding of SERS.     

Controlled Electrodeposition of Gold on Graphene: Maximization of the Defect‐Enhanced Raman Scattering Response

A reliable method to prepare a surface‐enhanced Raman scattering (SERS) active substrate is developed herein, by electrodeposition of gold nanoparticles (Au NPs) on defect‐engineered, large area chemical vapour deposition graphene (GR). A plasma treatment strategy is used in order to engineer the structural defects on the basal plane of large area single‐layer graphene. This defect‐engineered Au functionalized GR, offers reproducible SERS signals over the large area GR surface. The Raman data, along with X‐ray photoelectron spectroscopy and analysis of the water contact angle are used to rationalize the functionalization of the graphene layer. It is found that Au NPs functionalization of the “defect‐engineered” graphene substrates permits detection of concentrations as low as 10^?16 m for the probe molecule Rhodamine B, which offers an outstanding molecular sensing ability. Interestingly, a Raman signal enhancement of up to ≈10⁸ is achieved. Moreover, it is observed that GR effectively quenches the fluorescence background from the Au NPs and molecules due to the strong resonance energy transfer between Au NPs and GR. The results presented offer significant direction for the design and fabrication of ultra‐sensitive SERS platforms, and also open up possibilities for novel applications of defect engineered graphene in biosensors, catalysis, and optoelectronic devices.     

Mechanism of cellular uptake of graphene oxide studied by surface-enhanced Raman spectroscopy

The last few years have witnessed rapid development of biological and medical applications of graphene oxide (GO), such as drug/gene delivery, biosensing, and bioimaging. However, little is known about the cellular uptake mechanism and pathway of GO. In this work, surface-enhanced Raman scattering (SERS) spectroscopy is employed to investigate the cellular internalization of GO loaded with Au nanoparticles (NPs) by Ca Ski cells. The presence of Au NPs on the surface of GO enables detection of enhanced intrinsic Raman signals of GO inside the cell. The SERS results reveal that GO is distributed inhomogeneously inside the cell. Furthermore, internalization of Au-GO into Ca Ski cells is mainly via clathrin-mediated endocytosis, and is an energy-dependent process.     

Volume‐Enhanced Raman Scattering Detection of Viruses

Virus detection and analysis are of critical importance in biological fields and medicine. Surface‐enhanced Raman scattering (SERS) has shown great promise in small molecule and even single molecule detection, and can provide fingerprint signals of molecules. Despite the powerful detection capabilities of SERS, the size discrepancy between the SERS “hot spots” (generally, <10 nm) and viruses (usually, sub‐100 nm) yields poor detection reliability of viruses. Inspired by the concept of molecular imprinting, a volume‐enhanced Raman scattering (VERS) substrate composed of hollow nanocones at the bottom of microbowls (HNCMB) is developed. The hollow nanocones of the resulting VERS substrates serve a twofold purpose: 1) extending the region of Raman signal enhancement from the nanocone surface (e.g., surface “hot spots”) to the hollow area within the cone (e.g., volume “hot spots”)—a novel method of Raman signal enhancement, and 2) directing analyte such as viruses of a wide range of sizes to those VERS “hot spots” while simultaneously increasing the surface area contributing to SERS. Using HNCMB VERS substrates, greatly improved Raman signals of single viruses are demonstrated, an achievement with important implications in disease diagnostics and monitoring, biomedical fields, as well as in clinical treatment.     

Graphene Oxide‐Assisted Synthesis of Pt–Co Alloy Nanocrystals with High‐Index Facets and Enhanced Electrocatalytic Properties

Metal nanocrystals (NCs) are grown directly on the surface of reduced graphene oxide (rGO), which can maximize the rGO‐NCs contact/interaction to achieve the enhanced catalytic activity. However, it is difficult to control the size and morphology of metal NCs by in situ method due to the effects of functional groups on the surface of GO, and as a result, the metal NCs/rGO hybrids are conventionally synthesized by two‐step method. Herein, one‐pot synthesis of Pt–Co alloy NCs is demonstrated with concave‐polyhedrons and concave‐nanocubes bounded by {hkl} and {hk0} high‐index facets (HIFs) distributed on rGO. GO can affect the geometry and electronic structure of Pt–Co NCs. Thanks to the synergy of the HIFs and the electronic effect of the intimate contact/interaction between Pt–Co alloy and rGO, these as‐prepared Pt–Co NCs/rGO hybrids presents enhanced catalytic properties for the electrooxidation of formic acid, as well as for the oxygen reduction reaction.     

Magneto‐Plasmonic Au‐Fe Alloy Nanoparticles Designed for Multimodal SERS‐MRI‐CT Imaging

Diagnostic approaches based on multimodal imaging are needed for accurate selection of the therapeutic regimens in several diseases, although the dose of administered contrast drugs must be reduced to minimize side effects. Therefore, large efforts are deployed in the development of multimodal contrast agents (MCAs) that permit the complementary visualization of the same diseased area with different sensitivity and different spatial resolution by applying multiple diagnostic techniques. Ideally, MCAs should also allow imaging of diseased tissues with high spatial resolution during surgical interventions. Here a new system based on multifunctional Au‐Fe alloy nanoparticles designed to satisfy the main requirements of an ideal MCA is reported and their biocompatibility and imaging capability are described. The MCAs show easy and versatile surface conjugation with thiolated molecules, magnetic resonance imaging (MRI) and computed X‐ray tomography (CT) signals for anatomical and physiological information (i.e., diagnostic and prognostic imaging), large Raman signals amplified by surface enhanced Raman scattering (SERS) for high sensitivity and high resolution intrasurgical imaging, biocompatibility, exploitability for in vivo use and capability of selective accumulation in tumors by enhanced permeability and retention effect. Taken together, these results show that Au‐Fe nanoalloys are excellent candidates as multimodal MRI‐CT‐SERS imaging agents.     

A SERS‐Assisted 3D Barcode Chip for High‐Throughput Biosensing

A surface enhanced Raman scattering (SERS)‐assisted 3D barcode chip has been developed for high‐throughput biosensing. The 3D barcode is realized through joint 2D spatial encoding with the Raman spectroscopic encoding, which stores the SERS fingerprint information in the format of a 2D array. Here, the concept of SERS‐assisted 3D barcode is demonstrated through multiplex immunoassay, where simultaneous detection of multiple targets in different samples has been achieved using a microfluidic platform. First, multiple proteins in different samples are spatially separated using a microfluidic patterned antibody barcode substrate, forming a 2D hybridization array. Then the SERS probes are used to identify and quantify the proteins. As different SERS probes are labeled with different Raman reporters, they could be employed as “SERS tags” to incorporate spectroscopic information into the 3D barcode. In this 3D barcode, the 2D spatial information helps to differentiate the samples and targets while the SERS information allows quantitative multiplex detection. It is found that the SERS‐assisted 3D barcode chip can not only accomplish one‐step multiplex detection within 30 min but also achieve an ultrasensitivity down to 10 fg mL^?1 (≈70 aM), which is expected to provide a promising tool for high‐throughput biomedical applications.     

SERS‐Active‐Charged Microgels for Size‐ and Charge‐Selective Molecular Analysis of Complex Biological Samples

Surface‐enhanced Raman scattering (SERS) provides a dramatic increase of Raman intensity for molecules adsorbed on nanogap‐rich metal nanostructures, serving as a promising tool for molecular analysis. However, surface contamination caused by protein adsorption and low surface concentration of small target molecules reduce the sensitivity, which severely restricts the use of SERS in many applications. Here, charged microgels containing agglomerates of gold nanoparticles (Au NPs) are designed using droplet‐based microfluidics to provide a reliable SERS substrate with molecular selectivity and high sensitivity. The limiting mesh size of hydrogel enables the autonomous exclusion of large proteins and the charged matrix concentrates oppositely charged small molecules through electrostatic attraction. As nanogaps among Au NPs in the agglomerates enhance Raman intensity, Raman spectrum of the adsorbed molecules is selectively measured with high sensitivity in the absence of interruption from adhesive proteins. Therefore, the SERS‐active‐charged microgels can be used for direct analysis of pristine biological samples without the pretreatment steps of separation and concentration, which are commonly a prerequisite for Raman analysis. For the purpose of demonstration, a direct detection of fipronil sulfone with partial negative charges, a metabolite of toxic insecticide, dissolved in eggs using the positively charged microgels without any pretreatment of the samples, is shown.     

Microfluidic Surface‐Enhanced Raman Scattering Sensors Based on Nanopillar Forests Realized by an Oxygen‐Plasma‐Stripping‐of‐Photoresist Technique

A novel surface‐enhanced Raman scattering (SERS) sensor is developed for real‐time and highly repeatable detection of trace chemical and biological indicators. The sensor consists of a polydimethylsiloxane (PDMS) microchannel cap and a nanopillar forest‐based open SERS‐active substrate. The nanopillar forests are fabricated based on a new oxygen‐plasma‐stripping‐of‐photoresist technique. The enhancement factor (EF) of the SERS‐active substrate reaches 6.06 × 10⁶, and the EF of the SERS sensor is about 4 times lower due to the influence of the PDMS cap. However, the sensor shows much higher measurement repeatability than the open substrate, and it reduces the sample preparation time from several hours to a few minutes, which makes the device more reliable and facile for trace chemical and biological analysis.     

Sensitive and Reproducible Immunoassay of Multiple Mycotoxins Using Surface‐Enhanced Raman Scattering Mapping on 3D Plasmonic Nanopillar Arrays

A surface‐enhanced Raman scattering‐based mapping technique is reported for the highly sensitive and reproducible analysis of multiple mycotoxins. Raman images of three mycotoxins, ochratoxin A (OTA), fumonisin B (FUMB), and aflatoxin B1 (AFB1) are obtained by rapidly scanning the surface‐enhanced Raman scattering (SERS) nanotags‐anchoring mycotoxins captured on a nanopillar plasmonic substrate. In this system, the decreased gap distance between nanopillars by their leaning effects as well as the multiple hot spots between SERS nanotags and nanopillars greatly enhances the coupling of local plasmonic fields. This strong enhancement effect makes it possible to perform a highly sensitive detection of multiple mycotoxins. In addition, the high uniformity of the densely packed nanopillar substrate minimizes the spot‐to‐spot fluctuations of the Raman peak intensity in the scanned area when Raman mapping is performed. Consequently, this makes it possible to gain a highly reproducible quantitative analysis of mycotoxins. The limit of detections (LODs) are determined to be 5.09, 5.11, and 6.07 pg mL^?1 for OTA, FUMB, and AFB1, and these values are approximately two orders of magnitude more sensitive than those determined by the enzyme‐linked immunosorbent assays. It is believed that this SERS‐based mapping technique provides a facile tool for the sensitive and reproducible quantification of various biotarget molecules.     

Correct Spectral Conversion between Surface‐Enhanced Raman and Plasmon Resonance Scattering from Nanoparticle Dimers for Single‐Molecule Detection

Simultaneous measurement of surface‐enhanced Raman scattering (SERS) and localized surface plasmon resonance (LSPR) in nanoparticle dimers presents outstanding opportunities in molecular identification and in the elucidation of physical properties, such as the size, distance, and deformation of target species. SERS–LSPR instrumentation exists and has been used under limited conditions, but the extraction of SERS and LSPR readouts from a single measurement is still a challenge. Herein, the extraction of LSPR spectra from SERS signals is reported and a tool for measuring the interparticle distance from Raman enhancement data by the standardization of the SERS signal is proposed. The SERS nanoruler mechanism incorporates two important aspects (the LSPR scattering peak shift and the Raman shift for measuring interparticle distance), and signifies their exact one‐to‐one correspondence after spectral correction. The developed methodology is applied to calculate the interparticle distance between nanoparticle dimers from SERS signals, to detect and quantify DNA at the single‐molecule level in a base‐pair‐specific manner. It is also shown that the SERS nanoruler concept can be used in structural analysis for the specific detection of the interaction of immunoglobulin G (IgG) with its target from bianalyte Raman signals with identical shaping at single‐molecule resolution. The SERS profile shaping approach not only offers a new detection mechanism for single molecules, but also has excellent potential for studying protein interactions and the intracellular detection of mRNA.     

Bright Surface‐Enhanced Raman Scattering with Fluorescence Quenching from Silica Encapsulated J‐Aggregate Coated Gold Nanoparticles

Plexitonic nanoparticles offer variable optical properties through tunable excitations, in addition to electric field enhancements that far exceed molecular resonators. This study demonstrates a way to design an ultrabright surface‐enhanced Raman spectroscopy (SERS) signal while simultaneously quenching the fluorescence background through silica encapsulation of the semiconductor–metal composite nanoparticles. Using a multistep approach, a J‐aggregate‐forming organic dye is assembled on the surface of gold nanoparticles using a cationic linker. Excitonic resonance of the J‐aggregate–metal system shows an enhanced SERS signal at an appropriate excitation wavelength. Further encapsulation of the decorated particles in silica shows a significant reduction in the fluorescence signal of the Raman spectra (5× reduction) and an increase in Raman scattering (7× enhancement) when compared to phospholipid encapsulation. This reduction in fluorescence is important for maximizing the useful SERS enhancement from the particle, which shows a signal increase on the order of 10⁴ times greater than J‐aggregated dye in solution and 24 times greater than Oxonica S421 SERS tag. The silica layer also serves to promote colloidal stability. The combination of reduced fluorescence background, enhanced SERS intensity, and temporal stability makes these particles highly distinguishable with potential to enable high‐throughput applications such as SERS flow cytometry.     

Site‐Specific SERS Assay for Survivin Protein Dimer: From Ensemble Experiments to Correlative Single‐Particle Imaging

An assay for Survivin, a small dimeric protein which functions as modulator of apoptosis and cell division and serves as a promising diagnostic biomarker for different types of cancer, is presented. The assay is based on switching on surface‐enhanced Raman scattering (SERS) upon incubation of the Survivin protein dimer with Raman reporter‐labeled gold nanoparticles (AuNP). Site‐specificity is achieved by complexation of nickel‐chelated N‐nitrilo‐triacetic acid (Ni‐NTA) anchors on the particle surface by multiple histidines (His₆‐tag) attached to each C‐terminus of the centrosymmetric protein dimer. Correlative single‐particle analysis using light sheet laser microscopy enables the simultaneous observation of both elastic and inelastic light scattering from the same sample volume. Thereby, the SERS‐inactive AuNP‐protein monomers can be directly discriminated from the SERS‐active AuNP‐protein dimers/oligomers. This information, i.e. the percentage of SERS‐active AuNP in colloidal suspension, is not accessible from conventional SERS experiments due to ensemble averaging. The presented correlative single‐particle approach paves the way for quantitative site‐specific SERS assays in which site‐specific protein recognition by small chemical and in particular supramolecular ligands can be tested.     

Highly Surface‐roughened “Flower‐like” Silver Nanoparticles for Extremely Sensitive Substrates of Surface‐enhanced Raman Scattering

Surface‐enhanced Raman scattering (SERS) is a new optical spectroscopic analysis technique with potential for highly sensitive detection of molecules. Recently, many efforts have been made to find SERS substrates with high sensitivity and reproducibility. In this Research News article, we provide a focused review on the synthesis of monodispersed silver particles with a novel, highly roughened, “flower‐like” morphology by reducing silver nitrate with ascorbic acid in aqueous solutions. The nanometer‐scale surface roughness of the particles can provide several hot spots on a single particle, which significantly increases SERS enhancement. The incident polarization‐dependent SERS of individual particles is also studied. Although the different “hot spots” on a single particle can have a strong polarization dependency, the total Raman signals from an individual particle usually have no obvious polarization dependency. Moreover, these flower‐like silver particles can be measured by SERS with high enhancement several times, which indicates the high stability of the hot spots. Hence, the flower‐like silver particles here can serve as highly sensitive and reproducible SERS substrates.     

Competitive Reaction Pathway for Site‐Selective Conjugation of Raman Dyes to Hotspots on Gold Nanorods for Greatly Enhanced SERS Performance

Common methods to prepare SERS (surface‐enhanced Raman scattering) probes rely on random conjugation of Raman dyes onto metal nanostructures, but most of the Raman dyes are not located at Raman‐intense electromagnetic hotspots thus not contributing to SERS enhancement substantially. Herein, a competitive reaction between transverse gold overgrowth and dye conjugation is described to achieve site selective conjugation of Raman dyes to the hotspots (ends) on gold nanorods (GNRs). The preferential overgrowth on the nanorod side surface creates a barrier to prevent the Raman dyes from binding to the side surface except the ends of the GNRs, where the highest SERS enhancement factors are expected. The SERS enhancement observed from this special structure is dozens of times larger than that from conjugates synthesized by conventional methods. This simple and powerful strategy to prepare SERS probes can be extended to different anisotropic metal nanostructures with electromagnetic hotspots and has immense potential in in‐depth SERS‐based biological imaging and single‐molecule detection.     

Smart‐Dust‐Nanorice for Enhancement of Endogenous Raman Signal,Contrast in Photoacoustic Imaging,and T2‐Shortening in Magnetic Resonance Imaging

Raman microspectroscopy provides chemo‐selective image contrast, sub‐micrometer resolution, and multiplexing capabilities. However, it suffers from weak signals resulting in image‐acquisition times of up to several hours. Surface‐enhanced Raman scattering (SERS) can dramatically enhance signals of molecules in close vicinity of metallic surfaces and overcome this limitation. Multimodal, SERS‐active nanoparticles are usually labeled with Raman marker molecules, limiting SERS to the coating material. In order to realize multimodal imaging while acquiring the rich endogenous vibronic information of the specimen, a core–shell particle based on “Nanorice”, where a spindle‐shaped iron oxide core is encapsulated by a closed gold shell, is developed. An ultrathin layer of silica prevents agglomeration and unwanted chemical interaction with the specimen. This approach provides Raman signal enhancement due to plasmon resonance effects of the shell while the optical absorption in the near‐infrared spectral region provides contrast in photoacoustic tomography. Finally, T2‐relaxation of a magnetic resonance imaging (MRI) experiment is altered by taking advantage of the iron oxide core. The feasibility for Raman imaging is evaluated by nearfield simulations and experimental studies on the primate cell line COS1. MRI and photoacoustics are demonstrated in agarose phantoms illustrating the promising translational nature of this strategy for clinical applications in radiology.     

Native MicroRNA Targets Trigger Self‐Assembly of Nanozyme‐Patterned Hollowed Nanocuboids with Optimal Interparticle Gaps for Plasmonic‐Activated Cancer Detection

The modernized use of nucleic acid (NA) sequences to drive nanostructure self‐assembly has given rise to a new class of designed nanomaterials with controllable plasmonic functionalities for broad surface‐enhanced Raman scattering (SERS)‐based bioanalysis applications. Herein, dual usage of microRNAs (miRNAs) as both valuable cancer biomarkers and direct self‐assembly triggers is identified and capitalized upon for custom‐designed plasmonic nanostructures. Through strict NA hybridization of miRNA targets, Au nanospheres selectively self‐assemble onto hollowed Au/Ag alloy nanocuboids with ideal interparticle distances (≈2.3 nm) for optimal SERS signaling. The intrinsic material properties of the self‐assembled nanostructures further elevate miRNA detection performance via nanozyme catalytic SERS signaling cascades. This enables fM‐level miR‐107 detection limit within a clinically‐relevant range without any molecular target amplification. The miRNA‐triggered nanostructure self‐assembly approach is further applied in clinical patient samples, and showcases the potential of miR‐107 as a non‐invasive prostate cancer diagnostic biomarker. The use of miRNA targets to drive nanostructure self‐assembly holds great promise as a practical tool for miRNA detection in disease applications.     

Green synthesis of nanosilver‐decorated graphene oxide sheets

A green facile method has been successfully used for the synthesis of graphene oxide sheets decorated with silver nanoparticles (rGO/AgNPs), employing graphite oxide as a precursor of graphene oxide (GO), AgNO₃ as a precursor of Ag nanoparticles (AgNPs), and geranium (Pelargonium graveolens) extract as reducing agent. Synthesis was accomplished using the weight ratios 1:1 and 1:3 GO/Ag, respectively. The synthesised nanocomposites were characterised by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X‐ray diffraction, UV‐visible spectroscopy, Raman spectroscopy, energy dispersive X‐ray spectroscopy and thermogravimetric analysis. The results show a more uniform and homogeneous distribution of AgNPs on the surface of the GO sheets with the weight ratio 1:1 in comparison with the ratio 1:3. This eco‐friendly method provides a rGO/AgNPs nanocomposite with promising applications, such as surface enhanced Raman scattering, catalysis, biomedical material and antibacterial agent.Inspec keywords: silver, nanoparticles, graphene, nanocomposites, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X‐ray diffraction, ultraviolet spectra, visible spectra, X‐ray chemical analysis, surface enhanced Raman scattering, catalysis, nanofabricationOther keywords: antibacterial agent, biomedical material, catalysis, surface enhanced Raman scattering, rGO‐AgNP nanocomposite, eco‐friendly method, homogeneous distribution, thermogravimetric analysis, energy dispersive X‐ray spectroscopy, Raman spectroscopy, UV‐visible spectroscopy, X‐ray diffraction, atomic force microscopy, transmission electron microscopy, scanning electron microscopy, nanocomposites, reducing agent, geranium, graphene oxide sheets, graphite oxide, silver nanoparticles, green facile method     

Ag Nanoparticle‐Grafted PAN‐Nanohump Array Films with 3D High‐Density Hot Spots as Flexible and Reliable SERS Substrates

A facile fabrication approach of large‐scale flexible films is reported, with one surface side consisting of Ag‐nanoparticle (Ag‐NP) decorated polyacrylonitrile (PAN) nanohump (denoted as Ag‐NPs@PAN‐nanohump) arrays. This is achieved via molding PAN films with ordered nanohump arrays on one side and then sputtering much smaller Ag‐NPs onto each of the PAN‐nanohumps. Surface‐enhanced Raman scattering (SERS) activity of the Ag‐NPs@PAN‐nanohump array films can be improved by curving the flexible PAN film with ordered nanohump arrays during the Ag‐sputtering process to increase the density of the Ag‐NPs on the sidewalls of the PAN‐nanohumps. More 3D hot spots are thus achieved on a large‐scale. The Ag‐NPs@PAN‐nanohump array films show high SERS activity with good Raman signal reproducibility for Rhodamine 6G probe molecules. To trial their practical application, the Ag‐NPs@PAN‐nanohump array films are employed as SERS substrates for trace detection of trinitrotoluene and a congener of polychlorinated biphenyls. A lower detection limit of 10⁻¹²m and 10⁻⁵m can be achieved, respectively. Furthermore, the flexible Ag‐NPs@PAN‐nanohump array films can also be utilized as swabs to probe traces of methyl parathion on the surface of fruits such as apples. The as‐fabricated SERS substrates therefore have promising potential for applications in rapid safety inspection and environmental protection.     

Hybrid Structures for Surface‐Enhanced Raman Scattering: DNA Origami/Gold Nanoparticle Dimer/Graphene

A combination of three innovative materials within one hybrid structure to explore the synergistic interaction of their individual properties is presented. The unique electronic, mechanical, and thermal properties of graphene are combined with the plasmonic properties of gold nanoparticle (AuNP) dimers, which are assembled using DNA origami nanostructures. This novel hybrid structure is characterized by means of correlated atomic force microscopy and surface‐enhanced Raman scattering (SERS). It is demonstrated that strong interactions between graphene and AuNPs result in superior SERS performance of the hybrid structure compared to their individual components. This is particularly evident in efficient fluorescence quenching, reduced background, and a decrease of the photobleaching rate up to one order of magnitude. The versatility of DNA origami structures to serve as interface for complex and precise arrangements of nanoparticles and other functional entities provides the basis to further exploit the potential of the here presented DNA origami–AuNP dimer–graphene hybrid structures.