| 1. |
- Agostini, Marco, 1987, et al.
(författare)
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Designing Highly Conductive Functional Groups Improving Guest-Host Interactions in Li/S Batteries
- 2020
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 16:2
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Tidskriftsartikel (refereegranskat)abstract
- Li-sulfur batteries are of great interest due to their potential to surpass the energy densities of other battery types, but the low electronic conductivity of both sulfur and its discharge products requires the use of a conductive host material. The most common is the use of different porous carbons which normally are hydrophobic and hardly retain the polar discharge products of the Li/S reaction, such as Li2S and lithium polysulfides (LiPs), at the working electrode. Functionalized hosts have been proposed as a strategy to improve LiPs interactions, including the use of heteroatom doping, organic frameworks, metals, metal oxides, sulfide particles, and conductive polymers. Despite demonstrating an improved cycle life, the functionalized structures often have an intrinsic limitation related to a low electronic conductivity resulting in slow kinetics and poor rate capability of Li/S cells. Herein, recent research trends aimed at designing sulfur electrodes with highly conductive functional groups on nanostructured hosts surface are reviewed. The main concepts, key developments, and parameters for building 3D hosts architectures that enable fast charge rates and long cycle life at high sulfur loadings are discussed.
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| 2. |
- Ahsan, Aisha, et al.
(författare)
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Phase Transitions in Confinements: Controlling Solid to Fluid Transitions of Xenon Atoms in an On-Surface Network
- 2019
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Ingår i: Small. - : WILEY-V C H VERLAG GMBH. - 1613-6810 .- 1613-6829. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- This study reports on "phase" transitions of Xe condensates in on-surface confinements induced by temperature changes and local probe excitation. The pores of a metal-organic network occupied with 1 up to 9 Xe atoms are investigated in their propensity to undergo "condensed solid" to "confined fluid" transitions. Different transition temperatures are identified, which depend on the number of Xe atoms in the condensate and relate to the stability of the Xe clustering in the condensed "phase." This work reveals the feature-rich behavior of transitions of confined planar condensates, which provide a showcase toward future "phase-transition" storage media patterned by self-assembly. This work is also of fundamental interest as it paves the way to real space investigations of reversible solid to fluid transitions of magic cluster condensates in an array of extremely well-defined quantum confinements.
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| 3. |
- Aili, Daniel, 1977-, et al.
(författare)
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Colorimetric Protein Sensing by Controlled Assembly of Gold Nanoparticles Functionalized with Synthetic Receptors
- 2009
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 5:21, s. 2445-2452
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Tidskriftsartikel (refereegranskat)abstract
- A novel strategy is described for the colorimetric sensing of proteins, based on polypeptide-functionalized gold nanoparticles. Recognition is accomplished using a polypeptide sensor scaffold designed to specifically bind to the model analyte, human carbonic anhydrase II (HCAII). The extent of particle aggregation, induced by the Zn2+-triggered dimerization and folding of a second polypeptide also present on the surface of the gold nanoparticle, gives a readily detectable colorimetric shift that is dependent on the concentration of the target protein. In the absence of HCAII, particle aggregation results in a major redshift of the plasmon peak, whereas analyte binding prevented the formation of dense aggregates, significantly reducing the magnitude of the redshift. The versatility of the technique is demonstrated using a second model system based on the recognition of a peptide sequence from the tobacco mosaic virus coat protein (TMVP) by a recombinant antibody fragment (Fab57P). Concentrations down to approximate to 10 nM and approximate to 25 nM are detected for HCAII and Fab57P, respectively. This strategy is proposed as a generic platform for robust and specific protein analysis that can be further developed to monitor a wide range of target proteins.
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| 4. |
- Aili, Daniel, et al.
(författare)
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Colorimetric sensing: Small 21/2009
- 2009
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Ingår i: Small. - : John Wiley & Sons. - 1613-6810 .- 1613-6829. ; 5:21
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The cover picture illustrates a novel concept for colorimetric protein sensing based on the controllable assembly of polypeptide-functionalized gold nanoparticles. Recognition of the analyte is accomplished by polypeptide-based synthetic receptors immobilized on gold nanoparticles. Also present on the particle surface is a de novo-designed helix-loop-helix polypeptide that homodimerizes and folds into four-helix bundles in the presence of Zn2+, resulting in particle aggregation. Analyte binding interferes with the folding-induced aggregation, giving rise to a clearly detectable colorimetric response.
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| 5. |
- Andersson, Per Ola, et al.
(författare)
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Polymorph and size dependent uptake and toxicity of TiO2 nanoparticles in living lung epithelial cells
- 2011
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 7:4, s. 514-523
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Tidskriftsartikel (refereegranskat)abstract
- The cellular uptake and distribution of five types of well-characterized anatase and rutile TiO(2) nanoparticles (NPs) in A549 lung epithelial cells is reported. Static light scattering (SLS), in-vitro Raman microspectroscopy (mu-Raman) and transmission electron spectroscopy (TEM) reveal an intimate correlation between the intrinsic physicochemical properties of the NPs, particle agglomeration, and cellular NP uptake. It is shown that mu-Raman facilitates chemical-, polymorph-, and size-specific discrimination of endosomal-particle cell uptake and the retention of particles in the vicinity of organelles, including the cell nucleus, which quantitatively correlates with TEM and SLS data. Depth-profiling mu-Raman coupled with hyperspectral data analysis confirms the location of the NPs in the cells and shows that the NPs induce modifications of the biological matrix. NP uptake is found to be kinetically activated and strongly dependent on the hard agglomeration size-not the primary particle size-which quantitatively agrees with the measured intracellular oxidative stress. Pro-inflammatory responses are also found to be sensitive to primary particle size.
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| 6. |
- Andõn, F. T., et al.
(författare)
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Biodegradation of Single-Walled Carbon Nanotubes by Eosinophil Peroxidase
- 2013
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Ingår i: Small. - : Wiley-VCH Verlagsgesellschaft. - 1613-6810 .- 1613-6829. ; 9:16, s. 2721-2729
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Tidskriftsartikel (refereegranskat)abstract
- Eosinophil peroxidase (EPO) is one of the major oxidant-producing enzymes during inflammatory states in the human lung. The degradation of single-walled carbon nanotubes (SWCNTs) upon incubation with human EPO and H2O 2 is reported. Biodegradation of SWCNTs is higher in the presence of NaBr, but neither EPO alone nor H2O2 alone caused the degradation of nanotubes. Molecular modeling reveals two binding sites for SWCNTs on EPO, one located at the proximal side (same side as the catalytic site) and the other on the distal side of EPO. The oxidized groups on SWCNTs in both cases are stabilized by electrostatic interactions with positively charged residues. Biodegradation of SWCNTs can also be executed in an ex vivo culture system using primary murine eosinophils stimulated to undergo degranulation. Biodegradation is proven by a range of methods including transmission electron microscopy, UV-visible-NIR spectroscopy, Raman spectroscopy, and confocal Raman imaging. Thus, human EPO (in vitro) and ex vivo activated eosinophils mediate biodegradation of SWCNTs: an observation that is relevant to pulmonary responses to these materials. Human eosinophil peroxidase (EPO) is able to degrade SWCNTs in vitro in the presence of H2O2. EPO is one of the major oxidant-generating enzymes present in human lungs during inflammatory states. The biodegradation of SWCNTs is evidenced also in an ex vivo culture system using primary murine eosinophils stimulated to undergo degranulation. These results are relevant to potential respiratory exposure to carbon nanotubes.
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| 7. |
- Ao, Xianyu, et al.
(författare)
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Broadband Metallic Absorber on a Non-Planar Substrate
- 2015
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 11:13, s. 1526-1530
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Tidskriftsartikel (refereegranskat)abstract
- Absorbers for visible and near-infrared light are realized by depositing a thin iron layer on arrays of cones which are replicated from a porous template. The replicated conic structure itself is of several micrometers and ineffective at antireflection, but the subsequent deposition of iron on top generates nanometer-size columnar structures, and thus broadband absorption enhancement is achieved.
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| 8. |
- Baldwin, William J., et al.
(författare)
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Dynamic Local Structure in Caesium Lead Iodide: Spatial Correlation and Transient Domains
- 2023
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Ingår i: Small. - : WILEY-V C H VERLAG GMBH. - 1613-6810 .- 1613-6829.
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Tidskriftsartikel (refereegranskat)abstract
- Metal halide perovskites are multifunctional semiconductors with tunable structures and properties. They are highly dynamic crystals with complex octahedral tilting patterns and strongly anharmonic atomic behavior. In the higher temperature, higher symmetry phases of these materials, several complex structural features are observed. The local structure can differ greatly from the average structure and there is evidence that dynamic 2D structures of correlated octahedral motion form. An understanding of the underlying complex atomistic dynamics is, however, still lacking. In this work, the local structure of the inorganic perovskite CsPbI3 is investigated using a new machine learning force field based on the atomic cluster expansion framework. Through analysis of the temporal and spatial correlation observed during large-scale simulations, it is revealed that the low frequency motion of octahedral tilts implies a double-well effective potential landscape, even well into the cubic phase. Moreover, dynamic local regions of lower symmetry are present within both higher symmetry phases. These regions are planar and the length and timescales of the motion are reported. Finally, the spatial arrangement of these features and their interactions are investigated and visualized, providing a comprehensive picture of local structure in the higher symmetry phases.
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| 9. |
- Bally, Marta, 1981, et al.
(författare)
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Liposome and lipid bilayer arrays towards biosensing applications
- 2010
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 6:22, s. 2481-2497
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Tidskriftsartikel (refereegranskat)abstract
- Sensitive and selective biosensors for high-throughput screening are having an increasing impact in modern medical care. The establishment of robust protein biosensing platforms however remains challenging, especially when membrane proteins are involved. Although this type of proteins is of enormous relevance since they are considered in >60% of the pharmaceutical drug targets, their fragile nature (i.e., the requirement to preserve their natural lipid environment to avoid denaturation and loss of function) puts strong additional prerequisites onto a successful biochip. In this review, the leading approaches to create lipid membrane-based arrays towards the creation of membrane protein biosensing platforms are described. Liposomes assembled in micro- and nanoarrays and the successful set-ups containing functional membrane proteins, as well as the use of liposomes in networks, are discussed in the first part. Then, the complementary approaches to create cell-mimicking supported membrane patches on a substrate in an array format will be addressed. Finally, the progress in assembling free-standing (functional) lipid bilayers over nanopore arrays for ion channel sensing will be reported. This review illustrates the rapid pace by which advances are being made towards the creation of a heterogeneous biochip for the high-throughput screening of membrane proteins for diagnostics, drug screening, or drug discovery purposes.
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| 10. |
- Bansal, Akshaya, et al.
(författare)
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Quasi-Continuous Wave Near-Infrared Excitation of Upconversion Nanoparticles for Optogenetic Manipulation of C. elegans
- 2016
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 12:13, s. 1732-1743
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Tidskriftsartikel (refereegranskat)abstract
- Optogenetics is an emerging powerful tool to investigate workings of the nervous system. However, the use of low tissue penetrating visible light limits its therapeutic potential. Employing deep penetrating near-infrared (NIR) light for optogenetics would be beneficial but it cannot be used directly. This issue can be tackled with upconversion nanoparticles (UCNs) acting as nanotransducers emitting at shorter wavelengths extending to the UV range upon NIR light excitation. Although attractive, implementation of such NIR-optogenetics is hindered by the low UCN emission intensity that necessitates high NIR excitation intensities, resulting in overheating issues. A novel quasi-continuous wave (quasi-CW) excitation approach is developed that significantly enhances multiphoton emissions from UCNs, and for the first time NIR light-triggered optogenetic manipulations are implemented in vitro and in C. elegans. The approach developed here enables the activation of channelrhodopsin-2 with a significantly lower excitation power and UCN concentration along with negligible phototoxicity as seen with CW excitation, paving the way for therapeutic optogenetics.
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