Green preparation and spectroscopic characterization of plasmonic silver nanoparticles using fruits as reducing agents

• Jes Ærøe Hyllested,
• Marta Espina Palanco,
• Nicolai Hagen,
• Klaus Bo Mogensen and
• Katrin Kneipp

Beilstein J. Nanotechnol. 2015, 6, 293–299, doi:10.3762/bjnano.6.27

• near-infrared-excited surface enhanced Raman scattering. In addition to the surface plasmon band, UV–visible absorption spectra show features in the UV range which indicates also the presence of small silver clusters, such as Ag42+. The increase of the plasmon absorption correlates with the decrease of

• extinction appears in the red and near infrared region. For pineapple extract, the formation of silver nanoparticles is a faster process. The first sign of a plasmonic band can be seen already after 4 minutes and the process stops after 30 minutes. The peak of the plasmon spectrum appears at 450 nm and shows

• Raman signal of the molecule. Using excitation in the NIR, the green silver nanoparticles provide only modest enhancement factors between 10 and 100 in agreement with computations of field enhancement factors for individual small silver spheres in the near infrared (NIR) [24]. The poor aggregation

Overview about the localization of nanoparticles in tissue and cellular context by different imaging techniques

• Anja Ostrowski,
• Daniel Nordmeyer,
• Alexander Boreham,
• Cornelia Holzhausen,
• Lars Mundhenk,
• Christina Graf,
• Martina C. Meinke,
• Annika Vogt,
• Sabrina Hadam,
• Jürgen Lademann,
• Eckart Rühl,
• Ulrike Alexiev and
• Achim D. Gruber

Beilstein J. Nanotechnol. 2015, 6, 263–280, doi:10.3762/bjnano.6.25

• emission of light at shorter wavelength than the excitation wavelength [91]. UCNP feature a reduced cytotoxicity compared to QD and are, in contrast to fluorescent dyes or QD, excited by near infrared (NIR) light. By using long-wavelength NIR instead of ultra violet (UV) light, background autofluorescence

Tunable light filtering by a Bragg mirror/heavily doped semiconducting nanocrystal composite

• Ilka Kriegel and
• Francesco Scotognella

Beilstein J. Nanotechnol. 2015, 6, 193–200, doi:10.3762/bjnano.6.18

• near infrared (vis–NIR) spectral region when employing varying carrier densities. As the tunable component, we implemented a dispersion of copper selenide (Cu2−xSe) NCs and a film of indium tin oxide (ITO) NCs, which are known to show optical tunablility with chemical or electrochemical treatments. We

Interaction of dermatologically relevant nanoparticles with skin cells and skin

• Annika Vogt,
• Fiorenza Rancan,
• Sebastian Ahlberg,
• Berouz Nazemi,
• Chun Sik Choe,
• Maxim E. Darvin,
• Sabrina Hadam,
• Ulrike Blume-Peytavi,
• Kateryna Loza,
• Jörg Diendorf,
• Matthias Epple,
• Christina Graf,
• Eckart Rühl,
• Martina C. Meinke and
• Jürgen Lademann

Beilstein J. Nanotechnol. 2014, 5, 2363–2373, doi:10.3762/bjnano.5.245

• microscopic measurements were performed by using the skin composition analyzer (River Diagnostics, Model 3510, Rotterdam, The Netherlands). The fingerprint region (400–2000 cm−1) excited by near-infrared laser radiation (785 nm, 25 mW on the skin) was used for sample analyses. Raman spectra were recorded from

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• and compositions, which altogether define the light absorbance, and so the LSPR spectral peak. As shown in Figure 4, depending on those parameters, the resonance frequency can be tuned over all the visible and near-infrared ranges [9][10][11][12][15]. For example, gold nanorods (Figure 4a) present two

Photodetectors based on carbon nanotubes deposited by using a spray technique on semi-insulating gallium arsenide

• Domenico Melisi,
• Maria Angela Nitti,
• Marco Valentini,
• Antonio Valentini,
• Teresa Ligonzo,
• Giuseppe De Pascali and
• Marianna Ambrico

Beilstein J. Nanotechnol. 2014, 5, 1999–2006, doi:10.3762/bjnano.5.208

• light in the range from ultraviolet to near infrared. The device spectral efficiency obtained from the electrical characterization is finally reported and an improvement of the photodetector behavior due to the nanotubes is presented and discussed. Keywords: multi-wall carbon nanotubes; photodetectors

Carbon-based smart nanomaterials in biomedicine and neuroengineering

• Antonina M. Monaco and
• Michele Giugliano

Beilstein J. Nanotechnol. 2014, 5, 1849–1863, doi:10.3762/bjnano.5.196

• near-infrared region as a photothermal agent for in vivo cancer treatment, while scrutinising the effects originating from different graphene sizes and coatings [97]. Several research groups have focused on graphene as biosensors. Dey et al. [98] developed an amperometric cholesterol biosensor; Tang

Silicon and germanium nanocrystals: properties and characterization

• Ivana Capan,
• Alexandra Carvalho and
• José Coutinho

Beilstein J. Nanotechnol. 2014, 5, 1787–1794, doi:10.3762/bjnano.5.189

• luminescence intensity in the visible and near-infrared region. A size-dependent blue shift of the luminescence comparable to porous Si is well documented. Figure 1 shows PL spectra of Si NCs produced by ion implantation and subsequent annealing [34]. The emission is tuned by varying the implantation and

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• , although graphene-based biomaterials are out of the scope of this mini-review, GO has been covalently functionalized with peptides, antibodies and other biomolecules for applications in diagnostics, novel therapeutic approaches and near infrared (NIR) photo-thermal therapies [53]. A representative work

Microstructural and plasmonic modifications in Ag–TiO₂ and Au–TiO₂ nanocomposites through ion beam irradiation

• Venkata Sai Kiran Chakravadhanula,
• Yogendra Kumar Mishra,
• Venkata Girish Kotnur,
• Devesh Kumar Avasthi,
• Thomas Strunskus,
• Vladimir Zaporotchenko,
• Dietmar Fink,
• Lorenz Kienle and
• Franz Faupel

Beilstein J. Nanotechnol. 2014, 5, 1419–1431, doi:10.3762/bjnano.5.154

• ,b suggest that each spectrum mainly consists of two types of information, i.e., i) band-edge at lower wavelength (~320 nm) which is due to TiO2 matrix and ii) a peak in the visible–near infrared region (from about 580 nm to 650 nm for the different spectra) that arises from surface plasmon resonance

Optimizing the synthesis of CdS/ZnS core/shell semiconductor nanocrystals for bioimaging applications

• Li-wei Liu,
• Si-yi Hu,
• Ying Pan,
• Jia-qi Zhang,
• Yue-shu Feng and
• Xi-he Zhang

Beilstein J. Nanotechnol. 2014, 5, 919–926, doi:10.3762/bjnano.5.105

• organic dyes, QDs have narrow emission peaks that can be systematically tuned from visible to near-infrared by manipulating their size, composition, and shape [1][2][3][4][5][6][7]. In addition, QDs exhibit a continuous absorption band behaviour that allows a single laser light source to excite

• functionalization, which demonstrates that the toxicity of cadmium QDs can be reduced by encapsulating them. Furthermore, it is possible to fabricate CdS/ZnS QDs that emit from the visible to the near-infrared (NIR) regions, and hence are suitable for bioimaging [22][23]. Several reports in the literature

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• also be utilized as “organic dyes” for the conversion of light to current under visible and/or near-infrared light irradiation [90][91][92]. These gold clusters with tens of atoms are much smaller than gold nanoparticles, which caused gold clusters to exhibit no localized SPR but a molecular orbital

• due to the photosensitization of carbon nanodots. By virtue of PL upconversion properties, carbon nanodots can also be used as photosensitizer to harness near-infrared light to further enhance the photocatalytic activity of some visible-light active semiconductors. Kang et al. recently reported that

• photoelectrochemcial hydrogen generation has also been explored [147]. In this case, carbon nanodots absorb near-infrared photons (λ > 750 nm) and emit visible photons through the upconversion effect to excite CdSe again. The strategy of these studies may pave the way for the design of near-infrared active

Hole-mask colloidal nanolithography combined with tilted-angle-rotation evaporation: A versatile method for fabrication of low-cost and large-area complex plasmonic nanostructures and metamaterials

• Jun Zhao,
• Bettina Frank,
• Frank Neubrech,
• Chunjie Zhang,
• Paul V. Braun and
• Harald Giessen

Beilstein J. Nanotechnol. 2014, 5, 577–586, doi:10.3762/bjnano.5.68

• near-infrared spectral range as well as antenna-assisted surface-enhanced infrared absorption (SEIRA) were demonstrated [9][10]. Also, nano-antennas with their ability to enhance light emission from single emitters as well as to concentrate incoming light into hot spots were utilized. Metamaterials

In vitro toxicity and bioimaging studies of gold nanorods formulations coated with biofunctional thiol-PEG molecules and Pluronic block copolymers

• Tianxun Gong,
• Douglas Goh,
• Malini Olivo and
• Ken-Tye Yong

Beilstein J. Nanotechnol. 2014, 5, 546–553, doi:10.3762/bjnano.5.64

• longitudinal absorption peak within the range from 600 to 1500 nm [6]. It is well recognized that near infrared (NIR) light is able to penetrate the human tissue up to a few centimeters since water and blood cells absorb light only minimally at this region. AuNRs can be designed to absorb light specifically in

One-step synthesis of high quality kesterite Cu₂ZnSnS₄ nanocrystals – a hydrothermal approach

• Vincent Tiing Tiong,
• John Bell and
• Hongxia Wang

Beilstein J. Nanotechnol. 2014, 5, 438–446, doi:10.3762/bjnano.5.51

• has a theoretical band gap of 1.5 eV and has high light absorption coefficient (>104 cm−1) in the range of visible and near infrared irradiation of solar spectrum [2][3][4]. Shockley–Queisser balanced calculations have predicted that the theoretical efficiency of PVs using light absorbers like CZTS is

Near-infrared dye loaded polymeric nanoparticles for cancer imaging and therapy and cellular response after laser-induced heating

• Tingjun Lei,
• Alicia Fernandez-Fernandez,
• Romila Manchanda,
• Yen-Chih Huang and
• Anthony J. McGoron

Beilstein J. Nanotechnol. 2014, 5, 313–322, doi:10.3762/bjnano.5.35

• that combine imaging and therapeutic agents. In our study, we use a new biocompatible and biodegradable polymer, termed poly(glycerol malate co-dodecanedioate) (PGMD), for the synthesis of nanoparticles (NPs) and loading of near-infrared (NIR) dyes. IR820 was chosen for the purpose of imaging and

• synthesis of PGMD polymer, PGMD NPs were also successfully formulated. Optical imaging has several advantages over more traditional imaging techniques (MRI, PET, CT, etc.), such as high spatial resolution, real time imaging, and systems that are usually smaller and less expensive. Near-infrared imaging dyes

• elimination half-life of over 30 h for IR820 compared to approximately 2 h for ICG [8]. Based on these advantages we chose IR820 as our near-infrared agent and we synthesized and characterized IR820-PGMD NPs for cancer imaging and HT applications. HT is used clinically as an adjuvant treatment with

Dye-doped spheres with plasmonic semi-shells: Lasing modes and scattering at realistic gain levels

• Nikita Arnold,
• Boyang Ding,
• Calin Hrelescu and
• Thomas A. Klar

Beilstein J. Nanotechnol. 2013, 4, 974–987, doi:10.3762/bjnano.4.110

• ; spaser; Introduction Noble metal nanoparticles are of current interest both in fundamental and applied science because of their localized plasmonic resonances (LPR) in the visible and near infrared range of the optical spectrum. The simplest nanoparticle geometry is spherical, but the spectral position

Template based precursor route for the synthesis of CuInSe₂ nanorod arrays for potential solar cell applications

• Mikhail Pashchanka,
• Jonas Bang,
• Niklas S. A. Gora,
• Ildiko Balog,
• Rudolf C. Hoffmann and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2013, 4, 868–874, doi:10.3762/bjnano.4.98

• range and a part of the near infrared diapason as well (with a threshold that corresponds to a bandgap energy of 1.03 eV). A future challenge would be the incorporation of the 3D aligned CISe nanorod arrays as absorber material in a solar cell. Obviously, one of the main challenges towards this end is

Probing the plasmonic near-field by one- and two-photon excited surface enhanced Raman scattering

• Katrin Kneipp and
• Harald Kneipp

Beilstein J. Nanotechnol. 2013, 4, 834–842, doi:10.3762/bjnano.4.94

• Plasmonic silver nanoaggregates The highest SERS enhancement levels obtained so far are related to silver or gold nanoparticles that form aggregates as “SERS-active substrates” and by using excitation in the near infrared [20][21][22]. The first SERS spectra of single molecules had been measured by using

Controlling the near-field excitation of nano-antennas with phase-change materials

• Tsung Sheng Kao,
• Yi Guo Chen and
• Ming Hui Hong

Beilstein J. Nanotechnol. 2013, 4, 632–637, doi:10.3762/bjnano.4.70

• switching the phase states of a GST thin film can be easily accomplished by various well-developed methods, such as electric current, optical pumping and thermal stimulus [23][24]. In the near-infrared (NIR) range, a drastic change in the real part of the refractive index from the phase transition and low

How to remove the influence of trace water from the absorption spectra of SWNTs dispersed in ionic liquids

• Juan Yang,
• Daqi Zhang and
• Yan Li

Beilstein J. Nanotechnol. 2011, 2, 653–658, doi:10.3762/bjnano.2.69

• to their chiralities is of great importance in the quantitative analysis of bulk SWNT samples. However, because water has strong absorption bands in the near-infrared (NIR) region where the E11 of semiconducting SWNTs lies, even a trace amount of water dissolved in an IL may introduce notable peaks

Precursor concentration and temperature controlled formation of polyvinyl alcohol-capped CdSe-quantum dots

• Chetan P. Shah,
• Madhabchandra Rath,
• Manmohan Kumar and
• Parma N. Bajaj

Beilstein J. Nanotechnol. 2010, 1, 119–127, doi:10.3762/bjnano.1.14

• samples were fluorescent at room temperature; the green fluorescence was assigned to band edge emission, and the near-infrared fluorescence peaks at about 665 and 865 nm were assigned to shallow and deep trap states emissions, respectively. The quantum dots were fairly stable up to several days. Keywords