This study investigated the effect of SWCNTs’ length on their antimicrobial activity to bacterial cells in suspensions. Three different lengths of SWCNTs (<1 μm, 1−5 μm, and ∼5 μm) were tested. At ...same weight concentration, longer SWCNTs exhibited stronger antimicrobial activity. The fluorescence and SEM images revealed that the longer SWCNTs aggregated with bacterial cells more effectively, whereas short length SWCNTs tended to aggregate themselves without involving many bacterial cells. Moreover, longer SWCNTs exhibited more pronounced concentration-dependence and treatment time-dependence on their antimicrobial activity.
The integration of different noble metal nanostructures, which exhibit desirable plasmonic and/or electrocatalytic properties, with electrospun polymer nanofibers, which display unique mechanical and ...thermodynamic properties, yields novel hybrid nanoscale systems of synergistic properties and functions. This review summarizes recent advances on how to incorporate noble metal nanoparticles into electrospun polymer nanofibers and illustrates how such integration paves the way towards chemical sensing applications with improved sensitivity, stability, flexibility, compatibility, and selectivity. It is expected that further development of this field will eventually make a wide impact on many areas of research.
Transition metal sulfide nanocrystals are developed as a theranostic platform through the protein‐nanoreactor approach with facile functionalization for multimodal NIRF/PA/SPECT/CT imaging and ...photothermal tumor ablation.
This study was designed to investigate the antimicrobial effects of CDots in combination with other antimicrobial reagents, including H2O2, Na2CO3, and AcOH (acetic acid). CDots were synthesized and ...passivated with 2,2'-(ethylenedioxy)bis(ethylamine) (EDA). The minimal inhibitory concentration (MIC) of CDots was 64 μg/mL on both Gram negative bacteria E.coli cells and Gram positive bacteria Bacillus subtilis cells. When CDots were combined with H2O2, antibacterial synergistic effects were observed based on the fractional inhibitory concentration (FIC) index, and further confirmed by an isobologram analysis and viable cell number counting methods. With the combination treatment of 10 μg/mL CDots with 8.82 mM H2O2, the viable E.coli cell numbers decreased 2.46 log, which was significant lower than the log reduction from 8.82 mM H2O2 (1.57 log) or 10 μg/mL CDots (0.14 log) treatment alone. However, the combination of CDots with Na2CO3 or AcOH did not show synergistic effects, instead, exhibiting indifference effects according to the FIC index. This study indicated that the combination of CDots with their synergistic antimicrobial reagents, such as H2O2, could reach the goal of inhibiting bacteria growth by using lower concentration of each individual chemical in the combination than using one chemical treatment alone, reduce the risks imposed on environmental health and the possibilities of the development of microbial resistances.
A straightforward procedure for removing commonly used surfactants in nanoparticle synthesis, PVP and oleylamine/oleic acid, from Pt nanocubes by electrochemical potential cycling in 0.5M NaOH is ...reported. The cyclic voltammetric results demonstrate that this procedure can effectively remove surfactants from Pt nanocubes, while preserving their surface structure.
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•Electrochemical potential cycling in 0.5M NaOH is applied to clean Pt NCbs.•PVP and oleylamine and/or oleic acid on Pt NCbs are efficiently removed.•The surface structure of Pt NCbs is preserved.
Carbon dots (CDots) are characterized by their optical properties including strong absorptions and bright and colorful fluorescence emissions in the visible spectrum and by their photoinduced redox ...characteristics as both potent electron acceptors and donors. The reported study was for a systematic comparison of CDots from different synthetic approaches based on the use of pre-existing small carbon nanoparticles sourced from pure carbon soot versus the formation of similar nanoparticles in situ via a one-pot thermal carbonization of organic molecular precursors, emphasizing spectroscopic characterizations over the visible spectrum. The results show that the CDots prepared by the latter under sufficiently robust processing conditions are generally no different from those from the former in terms of the observed optical properties and associated photoinduced redox characteristics in the application-wise more meaningful visible spectral region, suggesting a high stability or general applicability of the definition on CDots as surface-passivated small-carbon nanoparticles. Implications of the reported findings to the further understanding and mechanistic explorations of CDots, including the necessity to focus on the core carbon nanoparticles in CDots in such explorations, are highlighted and discussed.
Abstract
Rechargeable sodium-ion batteries are receiving intense interest as a promising alternative to lithium-ion batteries, however, the absence of high-performance anode materials limits their ...further commercialization. Here we prepare cobalt-doped tin disulfide/reduced graphene oxide nanocomposites via a microwave-assisted hydrothermal approach. These nanocomposites maintain a capacity of 636.2 mAh g
−1
after 120 cycles under a current density of 50 mA g
−1
, and display a capacity of 328.3 mA h g
−1
after 1500 cycles under a current density of 2 A g
−1
. The quantitative capacitive analysis demonstrates that the electrochemical performance of the nanocomposite originates from the combined effects of cobalt and sulfur doping, resulting in the enhanced pseudocapacitive contribution (52.8 to 89.8% at 1 mV s
−1
) of tin disulfide. This work provides insight into tuning the structure of layered transition metal dichalcogenides via heteroatom doping to develop high-performance anode materials for sodium-ion batteries.
Urchin-like hollow spheres (ULHS) with internal cavities and functional shells are critical for many applications such as drug delivery, catalysis and energy storage. We synthesized in this work the ...hexagonal structured (h-) (Gd, Eu)PO4 ULHS by a simple microwave method in the absence of any templates or surfactants in the reaction system, and the effects of subsequent calcination on the structure and morphology of the samples were investigated in detail. The products were formed by controlled aggregation and subsequent oriented growth of the (Gd, Eu)PO4 primary nanoparticles, and the average diameter of the sphere decreases with increasing Eu3+ incorporation. The mechanism of morphology evolution with the variation of reaction time, SO42-/RE3+ molar ratio, and pH value was also unveiled. Nitrogen adsorption-desorption measurement suggests the presence of mesopores (∼20 nm) in the ULHS. The integrated emission intensity of Eu3+ in h-(Gd0.90Eu0.10)PO4 ULHS is ∼1.5 times higher than that in nanorods (NR) benefit from the unique configuration of the coarse shell. Moreover, the h-(Gd0.90Eu0.10)PO4 ULHS exhibit sustained drug release behaviors, and a pH-sensitive drug-release pattern can be well achieved by changing the pH of the release medium. The facile synthesis strategy and the excellent performance of the h-(Gd0.90Eu0.10)PO4 ULHS may be of great significance for the preparation and application of other inorganic hollow spheres.
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•Urchin-like hollow spheres of (Gd,Eu)PO4 was realized by a simple microwave method.•The effects of Eu3+ doping and calcination on phase/morphology were deciphered.•Eu3+ emission intensity in h-(Gd0.90Eu0.10)PO4 ULHS is ∼1.5 times that in nanorods.•IBU releasing ability of ULHS was well defined at pH values of 2 and 9.
Density functional theory and time-dependent density functional theory investigations were performed on the geometrical structures, basic photophysical properties, phosphorescence quantum efficiency ...( Φ PL ), and reorganization energy ( λ ) calculations of a new potential class of tetradentate Pt( ii ) complexes Ptppz-O-Popy ( 1 ) (where ppz = phenyl-pyrazole; Popy = phenoxyl-pyridine), Ptpmi-O-Popy ( 2 ) (where pmi = phenyl-methylimidazole), Ptpmi-O-Cbpy ( 3 ) (where Cbpy = carbazolyl-pyridine) and Ptppz-O-Cbpy ( 4 ), which show highly efficient ( Φ PL > 80%) and deep-blue emission. Nonradiative decay processes were investigated in order to obtain a more reliable nonradiative decay rate comparison. The calculated results confirm that tetradentate Pt( ii ) complexes are conducive to maintaining the rigidity of the molecules. The extended conjugation complexes with carbazole groups in 3 and 4 can not only improve the structural rigidity but also enhance the capability and balance of charge transfer. Thereupon, the following two designed derivatives Ptpmi-O-Cbmi ( 5 ) and Ptpmi-O-Cbbm ( 6 ) which substitute pyridine with imidazole and benzimidazole based on complexes 3 and 4 are also considered for promising materials exploitation and theoretical understanding. The charge transfer balance performance and the radiative decay rate constant ( k r ) of 5 and 6 are greatly improved compared with 1–4 , and the better structural rigidity will weaken nonradiative decay pathways, which may result in a higher phosphorescence quantum efficiency. Therefore, complexes 5 and 6 through judicious molecular design will be promising candidates as highly efficient blue-emitting phosphorescent materials for applications.
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