Surface-enhanced Raman scattering of self-assembled thiol monolayers and supported lipid membranes on thin anodic porous alumina

• Marco Salerno,
• Amirreza Shayganpour,
• Barbara Salis and
• Silvia Dante

Beilstein J. Nanotechnol. 2017, 8, 74–81, doi:10.3762/bjnano.8.8

• with ≈160 nm pore diameter and ≈80 nm corresponding wall thickness to be prepared. The tAPA surfaces were made SERS-active by coating with a thin (≈25 nm) gold (Au) layer. The as obtained tAPA–Au substrates were incubated first with different thiols, namely mercaptobenzoic acid (MbA) and aminothiol (AT

• ), and then with phospholipid vesicles of different composition to form a supported lipid bilayer (SLB). At each step, the SERS substrate functionality was assessed, demonstrating acceptable enhancement (≥100×). The chemisorption of thiols during the first step and the formation of SLB from the vesicles

• during the second step, were independently monitored by using a quartz crystal microbalance with dissipation monitoring (QCM-D) technique. The SLB membranes represent a simplified model system of the living cells membranes, which makes the successful observation of SERS on these films promising in view

Surface-enhanced infrared absorption studies towards a new optical biosensor

• Lothar Leidner,
• Julia Stäb,
• Jennifer T. Adam and
• Günter Gauglitz

Beilstein J. Nanotechnol. 2016, 7, 1736–1742, doi:10.3762/bjnano.7.166

• gained some importance in the field of sensor applications during the last three decades [8][9][10]. The theory of SEIRA is similar to the theory of surface-enhanced Raman spectroscopy (SERS) where electrochemical and chemical mechanisms seem to be responsible for the signal enhancement [11]. The effect

Graphene-enhanced plasmonic nanohole arrays for environmental sensing in aqueous samples

• Christa Genslein,
• Peter Hausler,
• Eva-Maria Kirchner,
• Rudolf Bierl,
• Antje J. Baeumner and
• Thomas Hirsch

Beilstein J. Nanotechnol. 2016, 7, 1564–1573, doi:10.3762/bjnano.7.150

• -enhanced Raman scattering (SERS) in the year 2015 alone. In contrast, in the same year only 25 publications report on the enhancement of SPR signals by introducing nanostructured surfaces. One reason can be attributed to the different size of the sensing spots used in these two prominent techniques

Localized surface plasmons in structures with linear Au nanoantennas on a SiO₂/Si surface

• Ilya A. Milekhin,
• Sergei A. Kuznetsov,
• Ekaterina E. Rodyakina,
• Alexander G. Milekhin,
• Alexander V. Latyshev and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2016, 7, 1519–1526, doi:10.3762/bjnano.7.145

• or terahertz frequencies [11][12][13][14]. Nanoantennas exhibiting the LSPR in the optical spectral range are already used for surface-enhanced Raman scattering (SERS) [15][16][17][18][19], and for fluorescence enhancements [20][21][22]. Nanoantennas with the LSPR energy located in the infrared

Dealloying of gold–copper alloy nanowires: From hillocks to ring-shaped nanopores

• Adrien Chauvin,
• Cyril Delacôte,
• Mohammed Boujtita,
• Benoit Angleraud,
• Junjun Ding,
• Chang-Hwan Choi,
• Pierre-Yves Tessier and
• Abdel-Aziz El Mel

Beilstein J. Nanotechnol. 2016, 7, 1361–1367, doi:10.3762/bjnano.7.127

• nanowires exhibit a very high roughness and high specific surface making of them a promising candidate for the development of SERS-based sensors. Keywords: copper; dealloying; gold; hillocks; nanoporous; Introduction Improvement in nanoscience involves fundamental evolution in the synthesis and

• size and shape coupled to the alignment and periodic organization of the nanowires is expected to promote the SERS effect originating from such gold nanostructures. Experimental Nanopatterned substrates The nanopatterned silicon substrates used as a template to grow the nanowires were prepared using a

Tunable longitudinal modes in extended silver nanoparticle assemblies

• Serene S. Bayram,
• Klas Lindfors and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2016, 7, 1219–1228, doi:10.3762/bjnano.7.113

• of modern applications in surface-enhanced Raman spectroscopy (SERS), optical sensing and emission enhancement of molecules residing in the near field [33][34]. In addition to applications in spectroscopy, plasmonic interactions may also be exploited in other light-based devices. The miniaturization

• and transverse plasmonic modes, in contrast to the observations reported here. For example, resorcinol-reduced silver nanoparticles were aggregated by heating, but the aggregates, despite their enhanced SERS signals, did not exhibit interesting spectral properties [39]. Likewise, AgNPs self-assembled

• anisotropy, as revealed by the simulation data. A stronger spectral anisotropy is achieved by deuterating the ligand due to the formation of highly dense anisotropic silver aggregates, offering a feasible method of preparing competent SHG (second harmonic generation) and SERS-active substrates. Based on

Sandwich-like layer-by-layer assembly of gold nanoparticles with tunable SERS properties

• Zhicheng Liu,
• Lu Bai,
• Guizhe Zhao and
• Yaqing Liu

Beilstein J. Nanotechnol. 2016, 7, 1028–1032, doi:10.3762/bjnano.7.95

• 10.3762/bjnano.7.95 Abstract Sandwich-like layer-by-layer thin films consisting of polyelectrolytes and gold nanoparticles were utilized to construct surface-enhanced Raman scattering (SERS) substrates with tunable SERS properties. It is found that both the size of the nanoparticles in the layers and the

• interlayer distance significantly influence the SERS performance of the multilayered thin film. These simple, low-cost, easily processable and controllable SERS substrates have a promising future in the field of molecular sensing. Keywords: assembly; layer-by-layer; multilayer thin film; nanoparticle

• ; polyelectrolyte; Introduction Surface-enhanced Raman scattering (SERS) spectroscopy, which relies on metal nanostructures made of noble metals (Au, Ag and Cu) that sustain localized surface plasmon resonance (LSPR), is applied as a promising analytical tool for detecting and identifying trace amounts of

Templated green synthesis of plasmonic silver nanoparticles in onion epidermal cells suitable for surface-enhanced Raman and hyper-Raman scattering

• Marta Espina Palanco,
• Klaus Bo Mogensen,
• Marina Gühlke,
• Zsuzsanna Heiner,
• Janina Kneipp and
• Katrin Kneipp

Beilstein J. Nanotechnol. 2016, 7, 834–840, doi:10.3762/bjnano.7.75

• nanostructures generated in the extracellular space of onion layers and within the epidermal cell walls can serve as enhancing plasmonic structures for one- and two-photon-excited spectroscopy such as surface enhanced Raman scattering (SERS) and surface enhanced hyper-Raman scattering (SEHRS). Our studies

• to the plasmonic nanostructures are probed by surface-enhanced Raman scattering (SERS) and two-photon-excited analogous surface-enhanced hyper-Raman scattering (SEHRS) [21][22]. While SERS signals scale with the local optical field strengths by 104, SEHRS signals have a scaling factor of 106. This

• high non-linearity makes SEHRS a very sensitive method to probe spatial variations in local fields and to localize plasmonic nanostructures, surpassing also SERS. Here we compare SEHRS images and bright field microscopy of the onion cell layers. Additionally, our SERS and SEHRS experiments give

Direct formation of gold nanorods on surfaces using polymer-immobilised gold seeds

• Majid K. Abyaneh,
• Pietro Parisse and
• Loredana Casalis

Beilstein J. Nanotechnol. 2016, 7, 809–816, doi:10.3762/bjnano.7.72

• ], photocatalysis [25], chemical sensing, biosensing [26][27] and surface-enhanced Raman spectroscopy (SERS) [28]. Last but not least, the synthesis process can be easily extended to screen printing or other thick film deposition processes for batch synthesis procedures [29]. Results and Discussion There are

Highly compact refractive index sensor based on stripe waveguides for lab-on-a-chip sensing applications

• Chamanei Perera,
• Kristy Vernon,
• Elliot Cheng,
• Juna Sathian,
• Esa Jaatinen and
• Timothy Davis

Beilstein J. Nanotechnol. 2016, 7, 751–757, doi:10.3762/bjnano.7.66

• highly sensitive to the surrounding dielectric environment. This unique property is incredibly useful in sensing applications. Mach–Zehnder (MZ) interferometry [1][2][3][4][5], surface enhanced Raman spectroscopy (SERS) [6][7][8][9], ring resonators [10] and surface plasmon resonance (SPR) [11][12][13

Antibacterial activity of silver nanoparticles obtained by pulsed laser ablation in pure water and in chloride solution

• Brunella Perito,
• Emilia Giorgetti,
• Paolo Marsili and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2016, 7, 465–473, doi:10.3762/bjnano.7.40

• previously observed a strong surface-enhanced Raman scattering (SERS) signal from such AgNPs by “activating” the NP surface by the addition of a small quantity of LiCl to the colloid. Such surface effects could also influence the antimicrobial activity of the NPs. Their activity, on the other hand, could

• a strong increase of the Raman response of molecular adsorbates in the SERS (Surface Enhanced Raman Scattering) effect. A strong SERS signal from such AgNPs can be obtained by “activating” the NP surface by addition of a small quantity of LiCl to the colloid. In addition, a sizeable catalytic effect

• in LiCl solutions obtained from both ps and ns ablation, the higher antimicrobial activity compared with that shown by the corresponding colloid ablated in pure water could be explained on the basis of the increased surface activity. This is evidenced by the increase of both the SERS and catalytic

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

Hemolysin coregulated protein 1 as a molecular gluing unit for the assembly of nanoparticle hybrid structures

• Tuan Anh Pham,
• Andreas Schreiber,
• Elena V. Sturm (née Rosseeva),
• Stefan Schiller and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2016, 7, 351–363, doi:10.3762/bjnano.7.32

• parameter for the formation of Au NP assembly is the specific ionic strength in the mixture. The resulting network-like structure of Au NPs is characterized by Raman spectroscopy, showing surface-enhanced Raman scattering (SERS) by a factor of 8·104 and a stable secondary structure of the Hcp1_cys3 unit. In

• ; nanoparticles; self-assembly; SERS; Introduction Self-assembly plays a pivotal role in bottom-up strategies for the synthesis of advanced nanostructures [1]. The resulting assemblies can be one-, two- or three-dimensional. One-dimensional nanostructures show particularly great promise due to their large

• nanomaterials. Furthermore, kinetic investigation of the formation of such 1D Au NP structures and the utilization of this structure, for example, as a SERS template and catalyst are also of great interest. The formation kinetics of Au NP networks triggered by Hcp1_cys3 is investigated using UV–vis spectroscopy

Linear and nonlinear optical properties of hybrid metallic–dielectric plasmonic nanoantennas

• Mario Hentschel,
• Bernd Metzger,
• Bastian Knabe,
• Karsten Buse and
• Harald Giessen

Beilstein J. Nanotechnol. 2016, 7, 111–120, doi:10.3762/bjnano.7.13

• itself is not the source of the signal, but rather an optically active species is responsible and the antenna is “dark”. This observation is in particular true for surface-enhanced Raman scattering (SERS) [45][46][47] and for experiments on surface-enhanced infrared absorption spectroscopy (SEIRA) [48

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

• Martina Banchelli,
• Bruno Tiribilli,
• Roberto Pini,
• Luigi Dei,
• Paolo Matteini and
• Gabriella Caminati

Beilstein J. Nanotechnol. 2016, 7, 9–21, doi:10.3762/bjnano.7.2

• Sesto Fiorentino, Italy Department of Chemistry and CSGI, University of Florence, Via della Lastruccia 3–13, I-50019 Sesto Fiorentino, Italy 10.3762/bjnano.7.2 Abstract Hybrid graphene oxide/silver nanocubes (GO/AgNCs) arrays for surface-enhanced Raman spectroscopy (SERS) applications were prepared by

• 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

Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• , 400084 Cluj-Napoca, Romania 10.3762/bjnano.6.259 Abstract Chemiresistors are a class of sensitive electrical devices capable of detecting (bio)chemicals by simply monitoring electrical resistance. Sensing based on surface enhanced Raman scattering (SERS) represents a radically different approach, in

• share a common principle: nanometric interparticle gaps are needed, for electron tunneling in chemiresistors, and for enhancing electromagnetic fields by plasmon coupling in SERS-based sensors. By exploiting such nano-gaps in self-assembled films of gold nanoparticles, we demonstrate the proof of

• concept of a dual electrical/optical sensor, with both chemiresistive and SERS capabilities. The proposed device is realized by self-assembling 15 nm gold nanoparticles into few micrometers-wide strips across commercially available interdigitated electrodes. The dual-mode operation of the device is

Surface-enhanced Raman scattering by colloidal CdSe nanocrystal submonolayers fabricated by the Langmuir–Blodgett technique

• Alexander G. Milekhin,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Volodymyr M. Dzhagan,
• Ovidiu D. Gordan,
• Sergey L. Veber,
• Cameliu Himcinschi,
• Alexander V. Latyshev and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2015, 6, 2388–2395, doi:10.3762/bjnano.6.245

• 10.3762/bjnano.6.245 Abstract We present the results of an investigation of surface-enhanced Raman scattering (SERS) by optical phonons in colloidal CdSe nanocrystals (NCs) homogeneously deposited on both arrays of Au nanoclusters and Au dimers using the Langmuir–Blodgett technique. The coverage of the

• deposited NCs was less than one monolayer, as determined by transmission and scanning electron microscopy. SERS by optical phonons in CdSe nanocrystals showed a significant enhancement that depends resonantly on the Au nanocluster and dimer size, and thus on the localized surface plasmon resonance (LSPR

• ) energy. The deposition of CdSe nanocrystals on the Au dimer nanocluster arrays enabled us to study the polarization dependence of SERS. The maximal SERS signal was observed for light polarization parallel to the dimer axis. The polarization ratio of the SERS signal parallel and perpendicular to the dimer

Green and energy-efficient methods for the production of metallic nanoparticles

• Mitra Naghdi,
• Mehrdad Taheran,
• Satinder K. Brar,
• M. Verma,
• R. Y. Surampalli and
• J. R. Valero

Beilstein J. Nanotechnol. 2015, 6, 2354–2376, doi:10.3762/bjnano.6.243

• , surface-enhanced Raman scattering (SERS) detection and catalysis of chemical reactions. Furthermore, biocompatible and functionalized NPs have applications in diagnosis and treatment of cancer. For these two purposes, fluorescent and magnetic nanocrystals for detection of tumors and also nanosystems for

Self-organization of gold nanoparticles on silanated surfaces

• Htet H. Kyaw,
• Salim H. Al-Harthi,
• Azzouz Sellai and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2015, 6, 2345–2353, doi:10.3762/bjnano.6.242

• structures [8]. AuNPs have been studied intensively for a wide range of applications such as catalysis [9], biosensing [10], colorimetric sensing [11], optical sensing (surface plasmon resonance (SPR) and surface-enhanced Raman scattering (SERS)) [12][13], photonics [13][14], photovoltaic devices [15] and

Au nanoparticle-based sensor for apomorphine detection in plasma

• Chiara Zanchi,
• Andrea Lucotti,
• Matteo Tommasini,
• Sebastiano Trusso,
• Ugo de Grazia,
• Emilio Ciusani and
• Paolo M. Ossi

Beilstein J. Nanotechnol. 2015, 6, 2224–2232, doi:10.3762/bjnano.6.228

• concentration range between 3.3 × 10−4 M and 3.3 × 10−7 M. The experimental parameters have been investigated and the dynamic concentration range of the sensor has been assessed by the selection of two apomorphine surface enhanced Raman scattering (SERS) peaks. The sensor behavior used to detect apomorphine in

• unfiltered human blood plasma is presented and discussed. Keywords: apomorphine; Au NPs; nano-roughened films; pulsed laser deposition; self-assembled films; SERS; Introduction In recent years, the analytical applications of Raman spectroscopy and its enhanced variant employing plasmonic media, the surface

• enhanced Raman scattering (SERS) effect, have significantly grown [1][2][3][4][5][6][7]. These applications have been fostered by the availability of noble metal nanostructures, which are either intentionally fabricated with the aim of optimizing the signal intensity and reproducibility [2][3] or carefully

Formation of substrate-based gold nanocage chains through dealloying with nitric acid

• Ziren Yan,
• Ying Wu and
• Junwei Di

Beilstein J. Nanotechnol. 2015, 6, 1362–1368, doi:10.3762/bjnano.6.140

• -enhanced Raman scattering (SERS), imaging [9], and catalysis [10][11]. Up to now, several methods, such as template-based methods, Kirkendall effect, Ostward ripening, and galvanic replacement, have been developed to synthesize hollow metal nanostructures [12][13][14]. Among them, the galvanic replacement

• the Ag dissolves to generate a hollow structure. This leads to the formation of Au NCs with hollow interiors and porous surfaces. In some applications such as catalysis, sensors, and SERS, it is favorable for metal nanomaterials to be supported by a solid substrate. Although the fabrication of Au NCs

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• techniques such as fluorescence spectroscopy [76][77], Fourier transform infrared spectroscopy [78], Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS) [36][79] as well as circular dichroism spectroscopy [6][47][53][80][81]. Also, other established techniques were used to study protein

• employed surface enhanced Raman spectroscopy (SERS) to elucidate mechanistic aspects on insulin adsorption onto Au nanoshells [36]. SERS is a very powerful technique to study the adsorption of molecules on metallic nano-surfaces [119][120][121][122] and has been described in great detail [123][124][125

• ][126]. In the context of protein adsorption, it needs to be pointed out that the enhancement effect in SERS strongly depends on the distance between the Raman/SERS active bond and the surface of the SERS substrate [121][123][124][125][126][127]. An intriguing aspect in the work of Grass and Treuel [36

Combination of surface- and interference-enhanced Raman scattering by CuS nanocrystals on nanopatterned Au structures

• Alexander G. Milekhin,
• Nikolay A. Yeryukov,
• Larisa L. Sveshnikova,
• Tatyana A. Duda,
• Ekaterina E. Rodyakina,
• Victor A. Gridchin,
• Evgeniya S. Sheremet and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2015, 6, 749–754, doi:10.3762/bjnano.6.77

• nanocrystals (NCs) with a low areal density fabricated through the Langmuir–Blodgett technology on nanopatterned Au nanocluster arrays using a combination of surface- and interference-enhanced Raman scattering (SERS and IERS, respectively). Micro-Raman spectra of one monolayer of CuS NCs deposited on a bare Si

• substrate reveal only features corresponding to crystalline Si. However, a new relatively strong peak occurs in the Raman spectrum of CuS NCs on Au nanocluster arrays at 474 cm−1. This feature is related to the optical phonon mode in CuS NCs and manifests the SERS effect. For CuS NCs deposited on a SiO2

• advantages of SERS and IERS and demonstrate stronger SERS enhancement allowing for the observation of Raman signals from CuS NCs with an ultra-low areal density. Keywords: copper sulfide (CuS) nanocrystals; interference-enhanced Raman spectroscopy; phonons; surface-enhanced Raman spectroscopy; Introduction

Electromagnetic enhancement of ordered silver nanorod arrays evaluated by discrete dipole approximation

• Guoke Wei,
• Jinliang Wang and
• Yu Chen

Beilstein J. Nanotechnol. 2015, 6, 686–696, doi:10.3762/bjnano.6.69

• The enhancement factor (EF) of surface-enhanced Raman scattering (SERS) from two-dimensional (2D) hexagonal silver nanorod (AgNR) arrays were investigated in terms of electromagnetic (EM) mechanism by using the discrete dipole approximation (DDA) method. The dependence of EF on several parameters, i.e

• nanoarrays and incident excitations will shine light on the optimal design of efficient SERS substrates and improved performance. Keywords: discrete dipole approximation (DDA); enhancement factor; near-field; silver nanorod array; surface-enhanced Raman scattering (SERS); Introduction Surface-enhanced

• Raman scattering (SERS) has attracted substantial interest over the past decades due to its potential applications in biological sensing and chemical analysis with molecular specificity and ultrahigh sensitivity, which can be even down to the level of single molecules [1][2]. In addition, SERS can be a

Hollow plasmonic antennas for broadband SERS spectroscopy

• Gabriele C. Messina,
• Mario Malerba,
• Pierfrancesco Zilio,
• Ermanno Miele,
• Michele Dipalo,
• Lorenzo Ferrara and
• Francesco De Angelis

Beilstein J. Nanotechnol. 2015, 6, 492–498, doi:10.3762/bjnano.6.50

• (SERS) and are activated by a wide range of excitation wavelengths. The three-dimensional hollow nanoantennas were produced on an optical resist by a secondary electron lithography approach, generated by fast ion-beam milling on the polymer and then covered with silver in order to obtain plasmonic

• functionalities. The optical properties of these structures have been studied through finite element analysis simulations that demonstrated the presence of broadband absorption and multiband enhancement due to the unusual geometry of the antennas. The enhancement was confirmed by SERS measurements, which showed a

• field enhancement; plasmonics; Raman spectroscopy; SERS; Introduction Cells are extremely complex systems that consist of hundreds of different molecules that can react and give rise to many different chemical processes. In addition to the complexity of the cellular chemical environment, it must also