Herrerabuur1367

The possibility of detecting genetic mutations rapidly in physiological media through liquid biopsy has attracted the attention within the materials science community. The physical properties of nanoparticles combined with robust transduction methods ensure an improved sensitivity and specificity of a given assay and its implementation into point-of-care devices for common use. Covering the last twenty years, this review gives an overview of the state-of-the-art of the research on the use of gold nanoparticles in the development of colorimetric biosensors for the detection of single-nucleotide polymorphism as cancer biomarker. We discuss the main mechanisms of the assays that either are assisted by DNA-based molecular machines or by enzymatic reactions, summarize their performance and provide an outlook towards future developments. Copyright © 2020, Iglesias and Grzelczak; licensee Beilstein-Institut.We present a quantitative study of the current-voltage characteristics (CVC) of SFIFS Josephson junctions (S = bulk superconductor, F = metallic ferromagnet, I = insulating barrier) with weak ferromagnetic interlayers in the diffusive limit. The problem is solved in the framework of the nonlinear Usadel equations. We consider the case of a strong tunnel barrier such that the left SF and the right FS bilayers are decoupled. We calculate the density of states (DOS) in SF bilayers using a self-consistent numerical method. Then we obtain the CVC of corresponding SFIFS junctions, and discuss their properties for different set of parameters including the thicknesses of ferromagnetic layers, the exchange field, and the magnetic scattering time. We observe an anomalous nonmonotonic CVC in case of weak ferromagnetic interlayers, which we attribute to DOS energy dependencies in the case of small exchange fields in the F layers. Copyright © 2020, Karabassov et al.; licensee Beilstein-Institut.In this study, a new nanoporous material comprising NiMoO4 nanorods and Co3O4 nanoparticles derived from ZIF-67 supported by a cellulose-based carbon aerogel (CA) has been successfully synthesized using a two-step hydrothermal method. Due to its chemical composition, the large specific surface and the hierarchical porous structure, the NiMoO4@Co3O4/CA ternary composite yields electrodes with an enhanced specific capacitance of 436.9 C/g at a current density of 0.5 A/g and an excellent rate capability of 70.7% capacitance retention at 5.0 A/g. Moreover, an advanced asymmetric supercapacitor (ASC) is assembled using the NiMoO4@Co3O4/CA ternary composite as the positive electrode and activated carbon as the negative electrode. The ASC device exhibits a large capacitance of 125.4 F/g at 0.5 A/g, a maximum energy density of 34.1 Wh/kg at a power density of 208.8 W/kg as well as a good cyclic stability (84% after 2000 cycles), indicating its wide applicability in energy storage. Finally, our results provide a general approach to the construction of CA and MOF-based composite materials with hierarchical porous structure for potential applications in supercapacitors. Copyright © 2020, Wang et al.; licensee Beilstein-Institut.Background Quantum dots connected to larger systems containing a continuum of states like charge reservoirs allow the theoretical study of many-body effects such as the Coulomb blockade and the Kondo effect. Results Here, we analyze the nonequilibrium Kondo effect and transport phenomena in a quantum dot coupled to pure monolayer graphene electrodes under external magnetic fields for finite on-site Coulomb interaction. The system is described by the pseudogap Anderson Hamiltonian. We use the equation of motion technique to determine the retarded Green's function of the quantum dot. An analytical formula for the Kondo temperature is derived for electron and hole doping of the graphene leads. The Kondo temperature vanishes in the vicinity of the particle-hole symmetry point and at the Dirac point. In the case of particle-hole asymmetry, the Kondo temperature has a finite value even at the Dirac point. The influence of the on-site Coulomb interaction and the magnetic field on the transport properties of the system shows a tendency similar to the previous results obtained for quantum dots connected to metallic electrodes. Most remarkably, we find that the Kondo resonance does not show up in the density of states and in the differential conductance for zero chemical potential due to the linear energy dispersion of graphene. An analytical method to calculate self-energies is also developed which can be useful in the study of graphene-based systems. Conclusion Our graphene-based quantum dot system provides a platform for potential applications of nanoelectronics. TJ-M2010-5 datasheet Furthermore, we also propose an experimental setup for performing measurements in order to verify our model. Copyright © 2020, Máthé and Grosu; licensee Beilstein-Institut.Lipid nanoemulsions are attractive drug delivery systems for lipophilic drugs. To produce nanoemulsions with droplets of very small diameter ( less then 100 nm), we investigated thermotropic phase transitions as an alternative to the standard procedure of high-pressure homogenization. Employing shock dilution with ice-cold water during the phase inversion gives the opportunity to produce nanoemulsions without any use of potentially toxic organic solvents. The systematic investigation of the relation of the three involved components surfactant, aqueous phase and lipid phase showed that depending on the ratio of surfactant to lipid the emulsions contained particles of diameters between 16 and 175 nm with narrow polydispersity index distributions and uncharged surfaces. Nanoemulsions with particles of 50 and 100 nm in diameter showed very little toxicity to fibroblast cells in vitro. An unusual, exponential-like nonlinear increase in osmolality was observed with increasing concentration of the nonionic surfactant Kolliphor HS 15. The experimental results indicate, that nanoemulsions with particles of small and tunable size can be easily formed without homogenization by thermal cycling. Copyright © 2020, Busmann et al.; licensee Beilstein-Institut.