Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

• , which is known to enhance the SERS signal. An optimum value for interparticle gap and size of Au NPs is needed to enhance the SERS signal. In [68] and [34], the fabrication of highly ordered flower-like ZnO nanorods decorated with Ag NPs is described. Sub-10 nm nanogaps between adjacent Ag NPs were the

Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes

• Max Mennicken,
• Sophia Katharina Peter,
• Corinna Kaulen,
• Ulrich Simon and
• Silvia Karthäuser

Beilstein J. Nanotechnol. 2022, 13, 219–229, doi:10.3762/bjnano.13.16

• the redox behavior of the Ru(MPTP)2-complexes is preserved in the device geometry [15]. Here, we use nanodevices equipped with gaps between the nanoelectrodes in the range of 20 to 50 nm so that a countable number of Ru(MPTP)2–AuNP building blocks is needed to bridge the nanogaps. The thus formed Ru

• molecular building blocks. However, the nanogaps are bridged either directly by long Ru(TP)2-complex wires or with AuNPs functionalized with TP-based Ru complexes. We will show that it is not only a challenge to design and assemble a molecular device, but to address the constituting elements so that the

• electrically characterized before use to rule out material artifacts. Only nanogaps with a resistance above 10 TΩ were employed for further experiments. Representative SEM images of empty nanogaps, Ru(TP)2-complex wire devices and Ru(MPTP)2–AuNP devices are given in Supporting Information File 1, Figure S3

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

A silver-nanoparticle/cellulose-nanofiber composite as a highly effective substrate for surface-enhanced Raman spectroscopy

• Yongxin Lu,
• Yan Luo,
• Zehao Lin and
• Jianguo Huang

Beilstein J. Nanotechnol. 2019, 10, 1270–1279, doi:10.3762/bjnano.10.126

• and biological substances where the substrates are crucial for obtaining an enhanced Raman signal [43][44][45]. The Raman signal of SERS is enhanced remarkably in the “hot spots” that are generated in the nanogaps of plasmonic metal nanoparticles (e.g., Au, Ag and Cu) through the amplification of the

• electromagnetic field caused by localized surface plasmon resonance [46]. In order to create more nanogaps and to generate more hot spots to improve the SERS effect, a number of nanostructures based on metal particles were prepared by different methods, such as thermal evaporation [47], electrospray [48], inject

• demonstrated in Figure 1f, more nanogaps between the silver nanoparticles exist in the substrate Ag-NP/cellulose-NF–C, which would be beneficial for the enhanced SERS effect. Figure 2a shows the transmission electron microscopy (TEM) image of the sample Ag-NP/cellulose-NF–C showing the silver nanoparticles

Biomimetic synthesis of Ag-coated glasswing butterfly arrays as ultra-sensitive SERS substrates for efficient trace detection of pesticides

• Guochao Shi,
• Mingli Wang,
• Yanying Zhu,
• Yuhong Wang,
• Xiaoya Yan,
• Xin Sun,
• Haijun Xu and
• Wanli Ma

Beilstein J. Nanotechnol. 2019, 10, 578–588, doi:10.3762/bjnano.10.59

• a bio-scaffold for the coating with magnetron-sputtered Ag nanofilms. The thickness of Ag nanofilms and the size of the nanogaps deposited on the G.b. wing arrays can be easily controlled by tuning the sputtering time. In order to find the optimum SERS enhancement performance, the sputtering time is

• . Simultaneously, suitable nanogaps between the adjacent nanostructures were generated in which high near-field enhancement could be achieved. As shown in the inset of Figure 2e, where the Nano Measurer 1.2 software was used, the average width of the nanofilm was approximately 170 ± 10 nm (the average width was

• nanogaps can be easily controlled by adjusting the sputtering time. In addition, they reveal that our physical fabrication method could yield large-scale Ag nanofilms, unlike the synchronous reduction process reported in the previous report [28]. SERS sensitivity of 3D Ag-G.b. hybrid composites The Ag

Silencing the second harmonic generation from plasmonic nanodimers: A comprehensive discussion

• Jérémy Butet,
• Gabriel D. Bernasconi and
• Olivier J. F. Martin

Beilstein J. Nanotechnol. 2018, 9, 2674–2683, doi:10.3762/bjnano.9.250

• equation method. Various geometries are considered, including nanoantennas with cylindrical and rectangular arms as well as nanodimers with surface defects. The existence of the silencing of the second harmonic generation from plasmonic nanogaps is first confirmed, and the problem of the origin of the

• observations made for third order nonlinear optical processes. In that context, Berthelot et al. reported for the first time what they called the “silencing” of SHG from nanogaps, which could explain the low SHG observed experimentally [18]. These authors measured the SHG from the interstice between two gold

• nanowires with various gap sizes. They observed that the SHG does not increase as the gap between the two nanowires decreases, despite an increase of the fundamental field enhancement. Their experimental observations were supported by numerical results demonstrating that the SHG from nanogaps is not

Expanding the molecular-ruler process through vapor deposition of hexadecanethiol

• Alexandra M. Patron,
• Timothy S. Hooker,
• Daniel F. Santavicca,
• Corey P. Causey and
• Thomas J. Mullen

Beilstein J. Nanotechnol. 2017, 8, 2339–2344, doi:10.3762/bjnano.8.233

• employed to produce registered nanogaps between metal features. Expansion of this methodology to include molecules with other chemical functionalities could greatly expand the overall versatility, and thus the utility, of this process. Herein, we explore the use of alkanethiol molecules as the terminating

• layer of metal-ligated multilayers. During this study, it was discovered that the solution deposition of alkanethiol molecules resulted in low overall surface coverage with features that varied in height. Because features with varied heights are not conducive to the production of uniform nanogaps via

• , metal-ligated multilayers, both with and without an alkanethiol capping layer, were utilized to create nanogaps between Au features using the molecular-ruler process. Keywords: hybrid nanolithography; metal-ligated multilayer; molecular ruler; self-assembled monolayers; vapor-phase deposition

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

• quantitatively estimate the enhancement induced by nanoantennas (EFN). It can be calculated as the ratio of the areas covered by the nanogaps to the entire nanoantenna array and amounts to about 1/1200. Here, we suppose that the IR absorption predominantly takes place in the nanogap. Taking the maximum EF = 5

• for the 3 nm thick CoPc film, the enhancement induced by nanogaps in the array reaches the value of EFN = 6000. In accordance with previous studies [18][20][35], the vibrational modes observed in the SEIRA spectra exhibit a clear Fano line shape. Further applications of SEIRA for biological compounds

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

• scanning near-field optical microscopy. Keywords: aperture scanning near-field optical microscopy; gold rippled surface; localized hot spots; metal–dielectric−metal nanogaps; surface plasmon resonance; Introduction Metal nanostructures capable of producing localized surface plasmon polaritons (SPPs) are

• –metal local nanogaps for the resonant plasmonic fields. In turn, the rippled shape of the surface corrugation makes the optical properties highly dependent on the polarization which can be switched between two directions, thus p- or s-polarizations have been considered. Rippled surfaces describing

Growth and morphological analysis of segmented AuAg alloy nanowires created by pulsed electrodeposition in ion-track etched membranes

• Ina Schubert,
• Loic Burr,
• Christina Trautmann and
• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2015, 6, 1272–1280, doi:10.3762/bjnano.6.131

• Abstract Background: Multicomponent heterostructure nanowires and nanogaps are of great interest for applications in sensorics. Pulsed electrodeposition in ion-track etched polymer templates is a suitable method to synthesise segmented nanowires with segments consisting of two different types of materials

• . Additionally, we have dissolved the middle Ag-rich segments in order to create small nanogaps with controlled gap sizes. Annealing of the created structures allows us to influence their morphology. Conclusion: AuAg alloy nanowires, segmented wires and nanogaps with controlled composition and size can be

• synthesised by electrodeposition in membranes, and are ideal model systems for investigation of surface plasmons. Keywords: AuAg alloy; cyclic voltammetry; electrodeposition; ion-track technology; nanogaps; segmented nanowires; Introduction The synthesis of multicomponent heterostructure nanowires is