-
Gentry Peters posted an update 6 months, 2 weeks ago
Understanding of cobalt nanorods’ (Co NRs) formation still remains challenging when it comes to enhancing their anisotropic properties applicable in magnetic or catalytic areas. Herein, we propose a mechanism for the morphological transition from spherical cobalt nanoparticles (NPs) to Co NRs over time (9 h) in a mixture of and oleylamine (OAm). In the literature, we described how spherical Co NPs are synthesized via a disproportionation process. Based on in situ and pseudo in situ observations, two steps of this unique mechanism are characterized first by the dissolution of the spheres and then the regrowth in rods’ shape in the presence of an OAm template. Furthermore, ex situ experiments show that these steps are the result of interdependent reactions occurring between Co NPs, cobalt(ii) and OAm. The latter plays numerous roles in this synthesis as a surfactant, a disproportionation promoter, and a hydrogen source allowing the reduction of cobalt(ii) complexes; its ammonium salt derivative is involved in oxidative etching of Co NPs and it promotes the anisotropic growth in NRs. These coupling actions of reduction and etching generate two cobalt reservoirs of nuclei under thermodynamic conditions.A new paddlewheel-type diruthenium complex with 2-amino-3-(trifluoromethyl)pyridine (amtfmp) (), which shows intense and characteristic near-infrared (NIR) and visible absorption, has been developed and structurally characterized by single crystal X-ray diffraction (SCXRD) analyses. check details This complex exhibits reversible and dramatic NIR and visible electrochromic behavior from deep-blue () to pink (-) due to the ON-OFF switching of its characteristic ligand-to-metal charge transfer (LMCT) and d-d absorption bands in response to an external voltage or chemical reagent such as decamethylcobaltocene (CoCp*2). The one-electron reduced species of , i.e., , was successfully isolated and fully characterized via SCXRD, the temperature dependence of the magnetic susceptibility, and mass spectroscopy, proving that this electrochromic behavior occurs without significant structural reorganization of .Fe/N/C full of ultrafine Fe-based species and pores is synthesized by pyrolyzing a g-C3N4-coordinated Fe matrix embedded in carbon for oxygen reduction. Enhanced oxygen reduction activity is observed on Fe/N/C with higher pore volume and the Fe/N/C catalyst with the largest pore volume shows the highest half-wave potential of 0.890 V.Correction for ‘Exploring the 3D structure and defects of a self-assembled gold mesocrystal by coherent X-ray diffraction imaging’ by Jerome Carnis et al., Nanoscale, 2021, DOI 10.1039/D1NR01806J.Molecular dynamics calculations of inelastic collisions of atomic oxygen with molecular nitrogen are known to show orders of magnitude discrepancies with experimental results in the range from room temperature to many thousands of degrees Kelvin. In this work, we have achieved an unprecedented quantitative agreement with experiments even at low temperature, by including a non-adiabatic treatment involving vibronic states on newly developed potential energy surfaces. This result paves the way for the calculation of accurate and detailed databases of vibrational energy exchange rates for this collisional system. This is bound to have an impact on air plasma simulations under a wide range of conditions and on the development of Very Low Earth Orbit (VLEO) satellites, operating in the low thermosphere, objects of great technological interest due to their potential at a competitive cost.Biothiols are widely involved in various important physiological activities and play a significant role in maintaining redox homeostasis in living organisms. Herein, we designed and synthesized three new asymmetric fluorescent probes (BDP-S-Ph, BDP-S-ENE and BDP-S-R) to discriminate Cys from Hcy/GSH. These probes reacted with Cys to form meso-amino-BODIPYs via SNAr substitution-rearrangement, thereby inducing a fluorescence turn-on effect. Moreover, they could selectively and sensitively detect Cys in solution with low detection limits (50 nM, 28 nM and 87 nM, respectively). Through comparing the response rates of the three probes to Cys, we concluded that the increase of conformational restrictions led to a decrease in probe reactivity. Besides, the sensing mechanism was demonstrated by mass spectrometry. Furthermore, cell experiments indicated that the probes were able to image exogenous and endogenous Cys through green or red channels in living cells.The exploration of high-performance cathode candidates is of great significance for aqueous aluminum-metal batteries (AAMBs). Here, we, for the first time, report tetrachloro-1,4-benzoquinone (TCQ) as a superior organic AAMB cathode. Owing to its high reversible conversion between the carbonyl and hydroxyl groups, the TCQ cathode delivers a remarkable electrochemical performance.In recent years, public attention has drawn to food safety due to the constant outbreaks of foodborne diseases; subsequently, to control and prevent this group of diseases, early screening of foodborne pathogens has become significant. In this study, a new aptamer-based electrochemical sensor was proposed to detect Escherichia coli O157H7 (E. coli), one of the most threatening bacterial pathogens, using nanoparticles-modified glassy carbon electrode. Firstly, the electrode was coated with a reduced graphene oxide-poly(vinyl alcohol) and gold nanoparticles nanocomposite (AuNPs/rGO-PVA/GCE) to increase the electrode surface area and consequently raise the sensor sensitivity. Afterwards, to enhance the selectivity of the modified electrode, aptamers were attached to the surface of the prepared electrode. The prepared electrode was characterized using energy-dispersive spectroscopy, field-emission scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, and electrochemical impedance spectroscopy. The relationship of the E. coli concentration and the peak current in the range from 9.2 CFU mL-1 to 9.2 × 108 CFU mL-1 was linear, and the limit of detection was calculated as 9.34 CFU mL-1. The suitability of the proposed sensor for real sample measurements was investigated by recovery studies in tap water, milk, and meat samples. The results showed that the biosensor and traditional culture counting methods are equally sensitive for detecting E. coli.
Please follow & like us :)
All content contained on CatsWannaBeCats.Com, unless otherwise acknowledged,is the property of CatsWannaBeCats.Com and subject to copyright.