The influence of phthalocyanine aggregation in complexes with CdSe/ZnS quantum dots on the photophysical properties of the complexes

• Irina V. Martynenko,
• Anna O. Orlova,
• Vladimir G. Maslov,
• Anatoly V. Fedorov,
• Kevin Berwick and
• Alexander V. Baranov

Beilstein J. Nanotechnol. 2016, 7, 1018–1027, doi:10.3762/bjnano.7.94

• Technology, Dublin 8, Ireland 10.3762/bjnano.7.94 Abstract The formation of nonluminescent aggregates of aluminium sulfonated phthalocyanine in complexes with CdSe/ZnS quantum dots causes a decrease of the intracomplex energy transfer efficiency with increasing phthalocyanine concentration. This was

• ; Förster resonance energy transfer; photosensitizer; semiconductor nanocrystals; tetrapyrroles; Introduction Semiconductor quantum dots (QDs) and their complexes with organic molecules have been a subject of extensive research during the last couple of decades. In particular, complexes of QDs and

• , photoexcited tetrapyrrole molecules undergo intersystem crossing from a singlet state to a triplet state. Energy is then transferred from the triplet state to the surrounding oxygen molecules. This energy transfer converts oxygen to the extremely reactive singlet oxygen, which can destroy diseased cells [11

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

• input end to increase the energy transfer of incoming light into the input waveguide [22]. The gratings were excited through an inverted microscope set-up using a 633 nm wavelength laser, further details are provided in [22]. The plasmon propagation and coupling in the RI sensor was imaged using CdSe

Coupled molecular and cantilever dynamics model for frequency-modulated atomic force microscopy

• Michael Klocke and
• Dietrich E. Wolf

Beilstein J. Nanotechnol. 2016, 7, 708–720, doi:10.3762/bjnano.7.63

• integrals of the three cartesian components add up to zero (corresponding to energy transfer into lateral degrees of freedom) or not (corresponding to adhesion hysteresis). This is more elaborate and likely more error-prone than monitoring the energies directly. Simulation method It is not feasible to

• -values). It is due to an energy transfer into the lateral degree of freedom. A signature of this effect is that it is nearly equally strong on both sides of the points of strongest attraction between tip and substrate, so that the scan has two dissipation maxima per lattice constant, but only one

• soon as d becomes small enough and remains roughly constant below. At the same time, the frequency of the cantilever oscillation changes discontinuously. If the normal cantilever oscillation is damped, for lateral oscillations get excited, the energy transfer increases smoothly with decreasing d, due

Hierarchical coassembly of DNA–triptycene hybrid molecular building blocks and zinc protoporphyrin IX

• Rina Kumari,
• Sumit Singh,
• Mohan Monisha,
• Sourav Bhowmick,
• Anindya Roy,
• Neeladri Das and
• Prolay Das

Beilstein J. Nanotechnol. 2016, 7, 697–707, doi:10.3762/bjnano.7.62

• was chosen as a prototype where ROS generation is proportional to the extent of oxidation of DHR 123. The ROS generation was attributed to energy transfer from the PpIX molecules to neighboring oxygen atoms upon irradiation at 330 nm. The formation of R 123 from DHR 123 was quantified by steady-state

Fabrication and properties of luminescence polymer composites with erbium/ytterbium oxides and gold nanoparticles

• Julia A. Burunkova,
• Ihor Yu. Denisiuk,
• Dmitri I. Zhuk,
• Lajos Daroczi,
• Attila Csik,
• István Csarnovics and
• Sándor Kokenyesi

Beilstein J. Nanotechnol. 2016, 7, 630–636, doi:10.3762/bjnano.7.55

• nanoparticles is not always a good solution to the problem because of the possible decrease of luminescence intensity due to the counterproductive introduction of energy-transfer processes at high concentrations of rare earth ions. For example, as it was shown in [5] for Er-doped silicon materials, a practical

Organized films

• Maurizio Canepa and
• Helmuth Möhwald

Beilstein J. Nanotechnol. 2016, 7, 406–408, doi:10.3762/bjnano.7.35

• ]. Their impact on interface science over the last four decades was undoubtedly based on pioneering works such as the beautiful studies of Kuhn and Möbius on energy transfer between molecules arranged with angstrom precision [2], or the stimulating works of Roberts and Petty [3], which envisaged many

Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection

• Dinusha N. Udukala,
• Hongwang Wang,
• Sebastian O. Wendel,
• Aruni P. Malalasekera,
• Thilani N. Samarakoon,
• Asanka S. Yapa,
• Gayani Abayaweera,
• Matthew T. Basel,
• Pamela Maynez,
• Raquel Ortega,
• Yubisela Toledo,
• Leonie Bossmann,
• Colette Robinson,
• Katharine E. Janik,
• Olga B. Koper,
• Ping Li,
• Massoud Motamedi,
• Daniel A. Higgins,
• Gary Gadbury,
• Gaohong Zhu,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2016, 7, 364–373, doi:10.3762/bjnano.7.33

• sequence. A second dye (cyanine 5.5) is permanently linked to the dopamine coating (Figure 1). This design enables both, plasmon-resonance quenching (SET) [20][21] and Förster resonance energy transfer (FRET) quenching [20][22] of the tethered TCPP units. Once TCPP is released via proteolytic cleavage of

• -resonance quenching (dipole–surface energy transfer (SET) [20][21]) from TCPP to Fe/Fe3O4 and Förster resonance energy transfer (FRET [20][22]) from TCPP to cyanine 5.5. The latter is permanently tethered to the inorganic nanoparticle. For all of the employed consensus sequences, with the exceptions of

• effect” upon proteolytic cleavage: the fluorophore is switched on due to the increase in distance between the Fe/Fe3O4 core/shell nanoparticle, leading to decreased Förster resonance energy transfer (FRET) [21][24], k1, and dipole–surface energy transfer (SET) [20][22], k2. Further explanations are

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

• , researchers had the opportunity to investigate eco-friendly reagents and new energy transfer techniques. In order to substitute the harmful reagents with green ones, researchers worked on different types of saccharides, polyols, carboxylic acids, polyoxometalates and extracts of various plants that can play

• the role of reducers, stabilizers or solvents. Also, there are some reports on using ultraviolet (UV), gamma and microwave irradiation that are capable of reducing and provide uniform heating. According to the literature, it is possible to use green reagents and novel energy transfer techniques for

• production of NPs. However, these new synthesis routes should be optimized in terms of performance, cost, product quality (shape and size distribution) and scale-up capability. This paper presents a review on most of the employed green reagents and new energy transfer techniques for the production of

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

• Uliana Kostiv,
• Miroslav Šlouf,
• Hana Macková,
• Alexander Zhigunov,
• Hana Engstová,
• Katarína Smolková,
• Petr Ježek and
• Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

• nm) [14]. Upconversion proceeds by different mechanisms, such as energy transfer and excited-state absorption and photon avalanche. These three mechanisms are based on the sequential absorption of two or more photons. Upconversion emission proceeds by sequential absorption of two photons and leads to

• inorganic compounds at high temperatures. To investigate the optical properties of the OM–NaYF4:Yb3+/Er3+ nanoparticles prepared at different reaction temperatures, the upconversion emission spectra were recorded at 980 nm excitation (Figure 7a). The energy transfer upconversion started after sequential

• insufficient energy transfer to Er3+ and energy losses between the ions. When the particles were prepared at temperatures above 300 °C, luminescence intensities were slightly higher, indicating that maximum luminescence efficiency was achieved by optimizing the interatomic distance between the absorbers and

Nonconservative current-driven dynamics: beyond the nanoscale

• Brian Cunningham,
• Tchavdar N. Todorov and
• Daniel Dundas

Beilstein J. Nanotechnol. 2015, 6, 2140–2147, doi:10.3762/bjnano.6.219

• transport; failure mechanisms; nanoelectronic devices; nanomotors; Introduction The development of electronic devices at the nanoscale is a challenging avenue of research with the aim of improving their efficiency and performance. This requires an understanding of the mechanisms for energy transfer from

Thermoelectricity in molecular junctions with harmonic and anharmonic modes

• Bijay Kumar Agarwalla,
• Jian-Hua Jiang and
• Dvira Segal

Beilstein J. Nanotechnol. 2015, 6, 2129–2139, doi:10.3762/bjnano.6.218

• , Suzhou 215006, China 10.3762/bjnano.6.218 Abstract We study charge and energy transfer in two-site molecular electronic junctions in which electron transport is assisted by a vibrational mode. To understand the role of mode harmonicity/anharmonicity in transport behavior, we consider two limiting

• is notable that the only difference between the HO and AH models is the sign in the denominator. Note that we did not simplify the expression for the energy current above; the derivatives return energy transfer rates analogous to Equation 10, only with an additional energy variable in the integrand

Light-powered, artificial molecular pumps: a minimalistic approach

• Giulio Ragazzon,
• Massimo Baroncini,
• Serena Silvi,
• Margherita Venturi and
• Alberto Credi

Beilstein J. Nanotechnol. 2015, 6, 2096–2104, doi:10.3762/bjnano.6.214

• pseudorotaxane with respect to the axle. The excitation of the ring with 287 nm light is followed by energy transfer to the trans-axle, a process that can effectively take place only if the components are associated, and causes the trans→cis isomerization. Hence, upon irradiation at either 287 or 365 nm, the

The role of low-energy electrons in focused electron beam induced deposition: four case studies of representative precursors

• Rachel M. Thorman,
• Ragesh Kumar T. P.,
• D. Howard Fairbrother and
• Oddur Ingólfsson

Beilstein J. Nanotechnol. 2015, 6, 1904–1926, doi:10.3762/bjnano.6.194

• more important in FEBID is the fact that interaction of precursor molecules with the surface of the substrate may alter the DEA cross sections substantially. This may be simply due to the enabled energy transfer offering a new relaxation path that competes with DEA (and AD). Conversely, in other

• instances polarization interactions may stabilize the TNI with respect to autodetachment and facilitate DEA [41][42]. Dissociative ionization (Equation 2) is fundamentally different from DEA. Here, energy transfer from the incident electron leads to removal of a bound electron from the target molecule and

• increases as the electron energy increases and more higher-lying excitation channels open up, also contributing to the total cross section. Unlike DI, the energy transfer is largely confined to the electronic excitation energy, though the resulting electronic states may generally be expected to be

A facile method for the preparation of bifunctional Mn:ZnS/ZnS/Fe₃O₄ magnetic and fluorescent nanocrystals

• Houcine Labiadh,
• Tahar Ben Chaabane,
• Romain Sibille,
• Lavinia Balan and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2015, 6, 1743–1751, doi:10.3762/bjnano.6.178

• dominant one at approximately 584 nm (visible, orange wavelength region). The first emission is associated with transitions involving vacancy states of the ZnS host material [24][30], while the second one originates from the Mn2+ dopant, which is excited via energy transfer of the ZnS host followed by the

DNA–melamine hybrid molecules: from self-assembly to nanostructures

• Rina Kumari,
• Shib Shankar Banerjee,
• Anil K. Bhowmick and
• Prolay Das

Beilstein J. Nanotechnol. 2015, 6, 1432–1438, doi:10.3762/bjnano.6.148

• molecules can result in unique DNA-based nanostructures for application in molecular and cellular biophysics, as biomimetic systems, in energy transfer and photonics, and in diagnostics and therapeutics [18][19][20][21]. Moreover, as a bottom-up technique, such a methodology can contribute to molecular

Natural and artificial binders of polyriboadenylic acid and their effect on RNA structure

• Giovanni N. Roviello,
• Domenica Musumeci,
• Valentina Roviello,
• Marina Pirtskhalava,
• Alexander Egoyan and
• Merab Mirtskhulava

Beilstein J. Nanotechnol. 2015, 6, 1338–1347, doi:10.3762/bjnano.6.138

• affinity constant of about 104 M−1, (b) a remarkable energy transfer from adenine base pairs to the ligand, as well as (c) a significant conformational variation of the poly(rA) duplex. Calorimetry studies evidenced an exothermic- and enthalpy-driven binding of sanguinarine to double helical poly(rA) in

Electronic interaction in composites of a conjugated polymer and carbon nanotubes: first-principles calculation and photophysical approaches

• Florian Massuyeau,
• Jany Wéry,
• Jean-Luc Duvail,
• Serge Lefrant,
• Abu Yaya,
• Chris Ewels and
• Eric Faulques

Beilstein J. Nanotechnol. 2015, 6, 1138–1144, doi:10.3762/bjnano.6.115

• network when nanotubes are semiconducting. Keywords: composite; conjugated polymer; DFT calculations; energy transfer; photoconductivity; single wall carbon nanotubes; time-resolved photoluminescence; Introduction Electroactive conjugated polymers (ECPs) are technologically promising for organic light

• photoexcitation. The efficiency of this approach is strongly dependent on the internal junctions between the polymer and the electron acceptor or donor. However, many fundamental questions remain regarding the underlying energy transfer processes involved. Phase separation within domains should not in principle

• exceed the exciton diffusion length [12], which is the case for ECP–fullerene-based solar cells in which fullerene molecules are able to capture the negative charges while the holes remain on the conjugated polymer [13]. Still, evidence for similar photoinduced charge-transfer or energy-transfer

Optimization of phase contrast in bimodal amplitude modulation AFM

• Mehrnoosh Damircheli,
• Amir F. Payam and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 1072–1081, doi:10.3762/bjnano.6.108

• are not associated with changes in the sign of the average value of the force. The origin of those regimes are discussed in terms of the different energies of the system, kinetic energy of the exited modes [35][36][37][38], the input energy [36] or the energy transfer between the modes [37]. In

• has a higher Hamaker constant. The power dissipated by the 2nd mode also shows a maximum with A1/A01 near 0.2 (Figure 4c). A discussion about the energy transfer among different modes is presented by Solares and co-workers [48]. The data plotted in Figure 3 and Figure 4 has been obtained by using the

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• emitted green luminescent light due to Tb3+. In the excitation spectra, a peak centered at 254 nm was observed which was attributed to Ce3+→Tb3+ energy transfer transition. Zhang et al. [27] reported the synthesis of a hybrid nanocomposite material of magnetic and luminescent NPs inside silica spheres

Carrier multiplication in silicon nanocrystals: ab initio results

• Ivan Marri,
• Marco Govoni and
• Stefano Ossicini

Beilstein J. Nanotechnol. 2015, 6, 343–352, doi:10.3762/bjnano.6.33

• absorbs at least one photon. This process was explained by considering a new energy transfer-based CM scheme, space-separated quantum cutting (SSQC). CM by SSQC is driven by the Coulomb interaction between carriers of different NCs and differs from traditional CM dynamics because the generated e–h pairs

• , energy transfer process that occurs when a high energy electron (hole) decays toward the conduction (valence) band CB (VB) edge by promoting the formation of an extra e–h pair in a nearby NC. CDCT, instead, is a Coulomb-driven, charge transfer mechanism that occurs when an electron (hole) decays toward

Tunable white light emission by variation of composition and defects of electrospun Al₂O₃–SiO₂ nanofibers

• Jinyuan Zhou,
• Gengzhi Sun,
• Hao Zhao,
• Xiaojun Pan,
• Zhenxing Zhang,
• Yujun Fu,
• Yanzhe Mao and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 313–320, doi:10.3762/bjnano.6.29

• 2:1 mullites have a wide band gap of 7.7 ± 0.2 eV, which is too wide for our case. Therefore, based on the above analysis, we assign an energy transfer mechanism to describe our PL results, as shown in Figure 5d. First, most of the energy needed for the excitation of radical carbonyl defects (≡Si(Al

• . The inset optical photos in (a) and (c) are the corresponding light emission spot of Al6Si4 and Al4Si6 samples, respectively. (d) Energy transfer diagram indicating the mechanism for Al2O3–SiO2 nanocomposite emission. The dashed lines represent light absorption, the solid lines radiative transitions

Synthesis and characterization of fluorescence-labelled silica core-shell and noble metal-decorated ceria nanoparticles

• Rudolf Herrmann,
• Markus Rennhak and
• Armin Reller

Beilstein J. Nanotechnol. 2014, 5, 2413–2423, doi:10.3762/bjnano.5.251

• ]. Fluorescence lifetime imaging microscopy (FLIM) on CeO2 agglomerates (50 ± 5 nm diameter of the circumscribed sphere) with and without platinum decoration did not show any difference between both samples. We can therefore conclude that there is no efficient energy transfer between metal and fluorescence dye

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• local dielectric function surrounding the Au nanoparticles; it is decreased significantly by the conjugation of an electron deficient material such as MnO or Fe3O4. A different approach utilizes an energy transfer between the gold domain and the metal oxide to explain the bathochromic shift [79][80]. On

Nanobioarchitectures based on chlorophyll photopigment, artificial lipid bilayers and carbon nanotubes

• Marcela Elisabeta Barbinta-Patrascu,
• Stefan Marian Iordache,
• Ana Maria Iordache,
• Nicoleta Badea and
• Camelia Ungureanu

Beilstein J. Nanotechnol. 2014, 5, 2316–2325, doi:10.3762/bjnano.5.240

• efficient energy transfer between the Chla molecules incorporated in liposomes (ordered along SWCNTs) as a result of interaction with the carbon nanotube sidewall. These findings are in agreement with our previous studies [4][5]. As can be seen in both Figure 4 and Figure 5, the liquid crystal phase of

• biomimetic membranes (above 41 °C) exhibits low anisotropy and high fluorescence emission intensity due to an increase in the lipid bilayer mobility and hence the chlorophyll has the possibility to move and to minimize the energy transfer leading to fluorescence quenching. In the gel phase of the artificial

• their small size as compared to the samples without cholesterol (see Figure 2). This leads to fluorescence quenching due to the efficient energy transfer between chlorophyll molecules, which are closer in small vesicles. Morphological characterization of biohybrid architectures Figure 6 shows a partial

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

• distinct propagating wave frequencies, promote to fulfil the phase matching condition Δk = 0 in a collinear geometry (see Figure 2b and Figure 2d). Therefore, specific beam propagation angles have to be set to achieve the phase matching and ensure an optimal energy transfer from the incident beams to the