Direct writing of gold nanostructures with an electron beam: On the way to pure nanostructures by combining optimized deposition with oxygen-plasma treatment

• Domagoj Belić,
• Mostafa M. Shawrav,
• Emmerich Bertagnolli and
• Heinz D. Wanzenboeck

Beilstein J. Nanotechnol. 2017, 8, 2530–2543, doi:10.3762/bjnano.8.253

• well as in nanomedicine [30]. Many applications require precise positioning of Au structures on the nanoscale, e.g., for fabrication of interconnects [31][32] and field emission tips [33] or in direct writing of plasmonic and photonic nanostructures and devices [4][34][35][36][37][38][39][40]. We

Refractive index sensing and surface-enhanced Raman spectroscopy using silver–gold layered bimetallic plasmonic crystals

• Somi Kang,
• Sean E. Lehman,
• Matthew V. Schulmerich,
• An-Phong Le,
• Tae-woo Lee,
• Stephen K. Gray,
• Rohit Bhargava and
• Ralph G. Nuzzo

Beilstein J. Nanotechnol. 2017, 8, 2492–2503, doi:10.3762/bjnano.8.249

• /bjnano.8.249 Abstract Herein we describe the fabrication and characterization of Ag and Au bimetallic plasmonic crystals as a system that exhibits improved capabilities for quantitative, bulk refractive index (RI) sensing and surface-enhanced Raman spectroscopy (SERS) as compared to monometallic

• plasmonic crystals of similar form. The sensing optics, which are bimetallic plasmonic crystals consisting of sequential nanoscale layers of Ag coated by Au, are chemically stable and useful for quantitative, multispectral, refractive index and spectroscopic chemical sensing. Compared to previously reported

• homometallic devices, the results presented herein illustrate improvements in performance that stem from the distinctive plasmonic features and strong localized electric fields produced by the Ag and Au layers, which are optimized in terms of metal thickness and geometric features. Finite-difference time

Ta₂N₃ nanocrystals grown in Al₂O₃ thin layers

• Krešimir Salamon,
• Maja Buljan,
• Iva Šarić,
• Mladen Petravić and
• Sigrid Bernstorff

Beilstein J. Nanotechnol. 2017, 8, 2162–2170, doi:10.3762/bjnano.8.215

• magnetic recording [6]. Currently, research in these fields is dominated by nanoparticles based on noble metals due to their strong plasmonic resonance in the visible part of the electromagnetic spectrum [7]. However, due to the wide range of parameters for separate applications, such as operation at

• longer wavelengths, high temperature durability, chemical stability, corrosion resistance, low cost or mechanical hardness, there is an increasing interest in various alternative materials that could optimize the device performance for specific plasmonic applications [8][9][10]. One promising group of

• alternative plasmonic materials includes the transition-metal nitrides such as TiN, ZrN, TaN or HfN [11][12][13]. Their advantages are compatibility with the silicon CMOS technology and physical properties suitable for harsh environments (high melting point, chemical stability) [14]. In addition, most of

Synthesis and characterization of noble metal–titania core–shell nanostructures with tunable shell thickness

• Bartosz Bartosewicz,
• Marta Michalska-Domańska,
• Malwina Liszewska,
• Dariusz Zasada and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2017, 8, 2083–2093, doi:10.3762/bjnano.8.208

• observed formation of the multi-core@shell particles, which are also very interesting due to the combined plasmonic effect of metallic cores. In the case of AgNPs, the synthesized metal NPs were stabilized with citrate ions either during the synthesis or after, in order to prevent aggregation in the

• interesting materials for application in dye-sensitized solar cells (DSSCs) and photocatalysis. In fact, it has been shown that plasmonic nanostructures can enhance the efficiency of DSSCs by four possible mechanisms [66]. The far-field coupling of scattered light and the near-field coupling of

• number of e−/h+ pairs should also result in improved photocatalytic properties of titania-based plasmonic nanostructures. Conclusion In this paper, we have shown that by using a general and simple approach it is possible to synthesize Ag@TiO2 and Au@TiO2 CSNs with shell thickness of ≈40–70 nm and 90 nm

Methionine-mediated synthesis of magnetic nanoparticles and functionalization with gold quantum dots for theranostic applications

• Arūnas Jagminas,
• Agnė Mikalauskaitė,
• Vitalijus Karabanovas and
• Jūrate Vaičiūnienė

Beilstein J. Nanotechnol. 2017, 8, 1734–1741, doi:10.3762/bjnano.8.174

• magneto-plasmonic cobalt ferrite NPs decorated with Au0/Au1+ quantum dots (QDs) were formed for the first time. The formation of plasmonic gold QDs at the surface of iron oxide-based NPs was confirmed by HRTEM, AFM, FTIR, XPS and chemical analysis. Results and Discussion Synthesis and characterization of

• additional shoulder peaked at 85.74 eV indicating the presence of Au+ species [31][32]. Their relative distribution reveals a fraction of about 13.7% of Au+ on the NPs surface of the total deposited gold content of 1.39% (Table 1). It is noticeable that plasmonic gold NPs upon excitation with nanosecond

• specific targeting ligands, such as aptamers and antibodies. This synthesis way may also be explored in future to design superparamagnetic, methionine-stabilized plasmonic magnetite NPs decorated with Au0/Au+1 QDs. Experimental Chemicals: All chemicals, including Co(II) and Fe(III) chlorides, and HAuCl4

Near-infrared-responsive, superparamagnetic Au@Co nanochains

• Varadee Vittur,
• Arati G. Kolhatkar,
• Shreya Shah,
• Irene Rusakova,
• Dmitri Litvinov and
• T. Randall Lee

Beilstein J. Nanotechnol. 2017, 8, 1680–1687, doi:10.3762/bjnano.8.168

• applications [7][8]. In parallel, there have been significant advances in the development of plasmonic nanoparticles (e.g., gold and silver), and efforts to tune the extinction wavelength (e.g., into the near infrared (NIR)) are ongoing [9]. Plasmonic nanoparticles exhibit intense colors and have been used in

• ][20]. Importantly, studies have focused on the synthesis of magnetic core–plasmonic shell structures to obtain versatile, hybrid nanoparticles with dual functionality [21][22][23]. The NIR region of light from approximately 800 to 1200 nm can penetrate human tissue (i.e., the ”water window”) and is

• minimally absorbed by tissue chromophores and water [24]. Therefore, tunable plasmonic nanoparticles that can respond to NIR light and can be manipulated with a magnetic field hold great promise. Among various magnetic nanoparticles, cobalt nanoparticles have attracted much interest due to their strong

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

Fixation mechanisms of nanoparticles on substrates by electron beam irradiation

• Daichi Morioka,
• Tomohiro Nose,
• Taiki Chikuta,
• Kazutaka Mitsuishi and
• Masayuki Shimojo

Beilstein J. Nanotechnol. 2017, 8, 1523–1529, doi:10.3762/bjnano.8.153

• -1 Sengen, Tsukuba, 305-0047, Japan 10.3762/bjnano.8.153 Abstract For applications such as the fabrication of plasmonic waveguides we developed a patterning technique to fabricate an array of nanoparticles on a substrate using focused electron beams (Noriki, T.; Abe, S.;.Kajikawa, K.; Shimojo, M

• been attracting attention because these arrays and patterns offer unique electrical and optical properties. One of the applications of such nanostructure arrays is plasmonic waveguides, in which the energy of light propagates because of the localized surface plasmon resonance (LSPR) effect [1][2]. In

• electron microscopy (SEM) images of the gold nanoparticles, the diameter of which was 50 nm for these images, on a silicon substrate. The particles arranged two-dimensionally without three-dimensional aggregation. As the distance between particles is important for plasmonic coupling, the distribution of

Two-dimensional silicon and carbon monochalcogenides with the structure of phosphorene

• Dario Rocca,
• Ali Abboud,
• Ganapathy Vaitheeswaran and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2017, 8, 1338–1344, doi:10.3762/bjnano.8.135

• dependent on the direction, with a value in the zigzag direction almost 100 times larger than the value in the armchair direction. Accordingly, this material is expected to exhibit a huge anisotropy in the hole mobility that might be of interest for less conventional plasmonic and thermoelectric devices, as

Surface-enhanced Raman spectroscopy of cell lysates mixed with silver nanoparticles for tumor classification

• Mohamed Hassoun,
• Iwan W.Schie,
• Tatiana Tolstik,
• Sarmiza E. Stanca,
• Christoph Krafft and
• Juergen Popp

Beilstein J. Nanotechnol. 2017, 8, 1183–1190, doi:10.3762/bjnano.8.120

• molecules. The plasmonic properties of SERS-active nanoparticles depend on the preparation conditions, the type of metal, the size and the shape of these nanoparticles [6][7][8][9][10], and their aggregation state [11][12]. Increasing the size of nanoparticle aggregates shifts the excitation wavelength to

Optical response of heterogeneous polymer layers containing silver nanostructures

• Miriam Carlberg,
• Florent Pourcin,
• Olivier Margeat,
• Judikaël Le Rouzo,
• Gérard Berginc,
• Rose-Marie Sauvage,
• Jörg Ackermann and
• Ludovic Escoubas

Beilstein J. Nanotechnol. 2017, 8, 1065–1072, doi:10.3762/bjnano.8.108

• properties. Thin film layers with inclusions of differently shaped nanoparticles, such as nanospheres and nanoprisms, and of different sizes, are optically characterized. The nanoparticles are produced by a simple chemical synthesis at room temperature in water. The plasmonic resonance peaks of the different

• the nanoparticles to complete the optical characterization. A simple analysis method is proposed to obtain the complex refractive index of nanospheres and nanoprisms in a polymer matrix. Keywords: nanoprisms; nanospheres; plasmonic nanoparticles; spectroscopic ellipsometry; thin film layers

• NPs, the thin film layers will absorb in the visible wavelength range. This leads to applications of plasmonic thin film layers for photodetectors [10], photovoltaics [6][11] or nonreflective coatings [12][13][14]. In this works, silver NPs were chosen for their high electric field enhancement in the

Nanoantenna-assisted plasmonic enhancement of IR absorption of vibrational modes of organic molecules

• Alexander G. Milekhin,
• Olga Cherkasova,
• Sergei A. Kuznetsov,
• Ilya A. Milekhin,
• Ekatherina E. Rodyakina,
• Alexander V. Latyshev,
• Sreetama Banerjee,
• Georgeta Salvan and
• Dietrich R. T. Zahn

Beilstein J. Nanotechnol. 2017, 8, 975–981, doi:10.3762/bjnano.8.99

• /bjnano.8.99 Abstract Nanoantenna-assisted plasmonic enhancement of IR absorption and Raman scattering was employed for studying the vibrational modes in organic molecules. Ultrathin cobalt phthalocyanine films (3 nm) were deposited on Au nanoantenna arrays with specified structural parameters. The

• conditions of plasmonic enhancement, a magnetic material can be employed for a wide range of applications [11]. A relatively low optical signal from the vibrational modes of organic molecules using conventional spectroscopic techniques such as infrared (IR) and Raman spectroscopy restricts their detection

• limit, which is crucial for sensor applications. The sensitivity of these optical methods can be drastically increased by implementation of nanoantenna-assisted plasmonic-enhanced spectroscopy techniques such as surface-enhanced IR absorption (SEIRA) [12] or surfaced-enhanced Raman scattering (SERS) [13

Near-field surface plasmon field enhancement induced by rippled surfaces

• Mario D’Acunto,
• Francesco Fuso,
• Ruggero Micheletto,
• Makoto Naruse,
• Francesco Tantussi and
• Maria Allegrini

Beilstein J. Nanotechnol. 2017, 8, 956–967, doi:10.3762/bjnano.8.97

• roughness patterns is analyzed, producing many different realizations of rippled surfaces. We demonstrate that irregular patterns act as metal–dielectric–metal local nanogaps (cavities) for the resonant plasmonic field. In turn, the numerical results are compared to experimental data obtained via aperture

• spectroscopy (TERS) [5], plasmonic photovoltaics [6][7][8], plasmonic nanosensors [9][10], and near-field optical theory [2][11][12]. It is commonly accepted that enormous field enhancements at the resonance of the optical response applied to randomly patterned metal nanostructures are highly dependent upon

• and height much smaller than the wavelength of typical plasmon resonances. Different top-down or bottom-up fabrication techniques have been introduced to produce metal nanostructures with active plasmonic reactivity [14]. For example, ion beam sputtering (IBS) is a widely employed bottom-up technique

3D Nanoprinting via laser-assisted electron beam induced deposition: growth kinetics, enhanced purity, and electrical resistivity

• Brett B. Lewis,
• Robert Winkler,
• Xiahan Sang,
• Pushpa R. Pudasaini,
• Michael G. Stanford,
• Harald Plank,
• Raymond R. Unocic,
• Jason D. Fowlkes and
• Philip D. Rack

Beilstein J. Nanotechnol. 2017, 8, 801–812, doi:10.3762/bjnano.8.83

• including: sensors [13][14][15], field emission cathodes [16][17], plasmonic elements [3][18], lithographic mask repair [19][20][21], scanning probe tips [22][23][24][25], photonic materials [26], magnetic materials [27][28], nanoparticle separations [29], and lithographic techniques [30][31] to name a few

Selective detection of Mg²⁺ ions via enhanced fluorescence emission using Au–DNA nanocomposites

• Tanushree Basu,
• Khyati Rana,
• Niranjan Das and
• Bonamali Pal

Beilstein J. Nanotechnol. 2017, 8, 762–771, doi:10.3762/bjnano.8.79

• to the size and shape dependent plasmonic interactions of AuNPs (33–78 nm) with DNA, the resultant Au–DNA nanocomposites (NCs) exhibit superior fluorescence emission due to chemical binding with Ca2+, Fe2+ and Mg2+ ions. A significant increase in fluorescence emission (λex = 260 nm) of Au–DNA NCs was

• , drug delivery, and DNA decoding. The importance of AuNPs is due to their unique optical properties related to the collective oscillation of the surface electrons, called surface plasmonic resonance (SPR) [1]. Since the frequency of this SPR band depends on the size, shape and chemical environment of

• modifications in the plasmonic spectra. The biophysical properties of DNA make it compatible for linkage with metals, which are useful in a variety of applications such as biosensor development. They can also be stabilized with a wide variety of molecules because of the alkyl thiol adsorption phenomena [3

Comparison of four methods for the biofunctionalization of gold nanorods by the introduction of sulfhydryl groups to antibodies

• Xuefeng Wang,
• Zhong Mei,
• Yanyan Wang and
• Liang Tang

Beilstein J. Nanotechnol. 2017, 8, 372–380, doi:10.3762/bjnano.8.39

• sizes with distinct plasmonic peaks and with aspect ratios of 3.5 and 5.0 were determined by TEM images; the longitudinal SPR peak wavelengths were 728 nm and 930 nm, respectively. Six nanometers of red shift were observed for the 728 nm GNRs upon binding of thiolated anti-IgG by Traut’s reagent, DTT

• –3 nm, whereas the biochip using SH-PEG-NH2/EDC modified antibody could not probe human IgG at 10 nM (only at 40 nM and above). Thus, the sensitivity of the label-free, plasmonic GNR nanochips resulting from SH-PEG-NH2 and EDC reaction is the lowest among the four methods. This decrease in

• glass substrates to construct a functional GNR biochip with thiolated anti-IgG using (A) Traut’s reagent, (B) DTT, (C) PEG6-CONHNH2, and (D) SH-PEG-NH2 combined with EDC reaction. Left: absorption spectra of GNRs with 728 and 930 nm longitudinal plasmonic bands. Right: fluorescence microscopy of the GNR

Laser irradiation in water for the novel, scalable synthesis of black TiO_x photocatalyst for environmental remediation

• Massimo Zimbone,
• Giuseppe Cacciato,
• Mohamed Boutinguiza,
• Vittorio Privitera and
• Maria Grazia Grimaldi

Beilstein J. Nanotechnol. 2017, 8, 196–202, doi:10.3762/bjnano.8.21

• dots [10], to the use of metal grafting [11][12][13][14] or plasmonic metal nanostructures [15][16][17][18][19] and the preparation of oxygen-deficient and/or hydrogen-rich TiOx [20][21][22]. We are interested, in particular, in this last approach. Hydrogenated black TiO2 has attracted attention due to

Tunable plasmons in regular planar arrays of graphene nanoribbons with armchair and zigzag-shaped edges

• Cristian Vacacela Gomez,
• Michele Pisarra,
• Mario Gravina and
• Antonello Sindona

Beilstein J. Nanotechnol. 2017, 8, 172–182, doi:10.3762/bjnano.8.18

• width, chirality and unit-cell length of each ribbon, as well as the in-plane vacuum distance between two contiguous ribbons. Our predictions, based on time-dependent density functional theory, in the random phase approximation, are expected to be of immediate help for measurements of plasmonic features

• losses with respect to more conventional plasmonic nanoparticles, such as, for example, silver and gold [17]. With the rise of low-dimensional materials, a number of theoretical and experimental studies have been oriented to launch, control, manipulate and detect plasmons in graphene-related and beyond

• support this result, we report in Figure 3 the macroscopic dielectric function and the EL function of the different GNR arrays for a selected momentum value (q = 0.011 Å−1) and a negative doping level (ΔEF = −0.1 eV). We see that 10ZGNR and 4ZGNR present similar plasmonic features, with the intraband

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

• is of critical importance in SERS [23]. The SEM images reported in Figure 1 show the good control achieved in both mean pore size and its dispersion and prove the long range uniformity of the surfaces with the Au coating to make it plasmonic-active. tAPA–Au substrates could possibly be used as a

Effect of Anderson localization on light emission from gold nanoparticle aggregates

• Mohamed H. Abdellatif,
• Marco Salerno,
• Gaser N. Abdelrasoul,
• Ioannis Liakos,
• Alice Scarpellini,
• Sergio Marras and
• Alberto Diaspro

Beilstein J. Nanotechnol. 2016, 7, 2013–2022, doi:10.3762/bjnano.7.192

• electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The dielectric constant of the surrounding medium plays a crucial role in determining the aggregate geometry, which affects the Anderson localization of light in the aggregates and hence causes a red-shift in the plasmonic

• nanoparticles, the electron oscillation is nonisotropic and localized along the principal axis [15] or at the points of maximum surface curvature. The asymmetry in localization then gives rise to additional shape-dependent depolarization of the plasmon, which results in the splitting of the plasmonic resonance

• optical coupling of the visible electromagnetic radiation with the plasmon oscillation, this quantized plasma oscillation can propagate along the metal depending on the shape and size of the AuNP aggregates. The modulation of the plasmonic resonance to the inter-subband electron transition results in

Hydrophilic silver nanoparticles with tunable optical properties: application for the detection of heavy metals in water

• Paolo Prosposito,
• Federico Mochi,
• Erica Ciotta,
• Mauro Casalboni,
• Fabio De Matteis,
• Iole Venditti,
• Laura Fontana,
• Giovanna Testa and
• Ilaria Fratoddi

Beilstein J. Nanotechnol. 2016, 7, 1654–1661, doi:10.3762/bjnano.7.157

• of the maximal value were detected in the plasmonic feature. The presence of Cu2+, Nd3+ and Ca2+ on the contrary does not produce any substantial modifications in the plasmonic absorption neither in the intensity nor in the position and shape. To quantitatively test the properties of the NPs we

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 to achieve low detection limits. To address this issue nanomaterials ranging from metallic nanoparticles, carbon-based structures to liposomes were used [10][11][12]. Plasmonic transducers are sensitive to changes of optical properties such as the dielectric constant and hence the refractive index

• next to their surface. The exponential decay of the plasmonic field generates a response affected by the penetrated volume within the solution [13]. Within conventional SPR sensing propagating surface plasmons (PSP) are the main parameter, defined as propagating charge oscillations on the surface of a

• arrays, has been designed and applied to bioanalytical sensing applications [17][18][19][20]. Nanohole arrays, which are characterized by combining localized and propagating surface plasmons, offer a possibility to tune the plasmonic features and therefore optimize the sensing performance for a specific

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

• between plasmonic excitations of gold nanoantennas and optical phonons in SiO2 leads to the appearance of new plasmon–phonon modes observed in the infrared transmission spectra the frequencies of which are well predicted by the simulations. Keywords: nanoantenna array; localised surface plasmon resonance

• ; plasmon–phonon interaction; phonons; SiO2; Introduction Plasmonic metamaterials remain the object of keen interest both in fundamental and applied research due to their unique optical properties including negative and zero refraction, focusing, filtering, polarization manipulation, etc. [1][2][3][4

Electric field induced structural colour tuning of a silver/titanium dioxide nanoparticle one-dimensional photonic crystal

• Eduardo Aluicio-Sarduy,
• Simone Callegari,
• Diana Gisell Figueroa del Valle,
• Andrea Desii,
• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2016, 7, 1404–1410, doi:10.3762/bjnano.7.131

• switching; photonic crystal; plasmonic nanoparticles; Introduction Structural colour is colour due to the Bragg reflection (in photonic structures for example) as opposed to colour from pigments or colour centres [1]. The active tuning of the structural colour in photonic crystals is a subject that has

• Figure 2, where the transmission spectrum of the photonic crystal is reported as a function of the applied voltage. The transmission is dominated by two strong bands at around 480 nm and 620 nm, ascribed to the plasmonic resonances of the silver nanoparticles and the photonic bandgap, respectively. We

• want to emphasize the fundamentally different nature of the two resonances observed in our device, namely the plasmonic resonance of the silver nanoparticle layer and that of the photonic bandgap. The pump–probe measurement in Figure 3a shows the transmission spectra of the transient absorption

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

• for larger-scale synthesis due to technical limitations. Other attempts such as assembling on templates of λ-DNA networks have not demonstrated the ability to generate discrete plasmonic modes, and, since they are substrate-based, lack the versatility of tuning the plasmonic bands [24]. Surfactant

• 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

• to transverse and longitudinal plasmon resonances, respectively (see numerical simulations and Figure 2). The red shift in the longitudinal plasmon is due to plasmonic coupling between extremely closely spaced particles enhanced by the short length of the ligands (0.7–1 nm). The appearance of a well