A quick one-step synthesis of luminescent gold nanospheres

Soft Matter ◽  
2020 ◽  
Vol 16 (48) ◽  
pp. 10865-10868
Author(s):  
Angela Candreva ◽  
Giuseppe Di Maio ◽  
Massimo La Deda
Keyword(s):  
Visible Spectrum ◽  
Luminescence Properties ◽  
Gold Nanospheres ◽  
Step Procedure ◽  
Wide Range ◽  
One Step ◽  
Application Fields

Luminescent gold nanospheres emissive in a wide range of the visible spectrum have been synthesized by a quick one-step procedure; the coexistence of the plasmonic and luminescence properties makes them useful in various application fields.

One-Step Synthesis of Indolizino[3,4,5-ab]isoindoles by Manganese(I)-Catalyzed C–H Activation: Structural Studies and Photophysical Properties

2022 ◽  
Author(s):  
Sara Cembellin ◽  
Ivan Maisuls ◽  
Constantin Gabriel Daniliuc ◽  
Helena Osthues ◽  
Nikos Doltsinis ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Regioselective Synthesis ◽  
Luminescence Properties ◽  
Structural Studies ◽  
Step Procedure ◽  
One Step

Herein, a regioselective synthesis of indolizino[3,4,5-ab]isoindoles (INIs), a valuable class of heterocycles with interesting luminescence properties, is described using manganese(I)-catalyzed C−H activation. The reported transformation proceeds in a one-step procedure...

scholarly journals A Photo-Enzymatic Cascade to Transform Racemic Alcohols into Enantiomerically Pure Amines

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 305 ◽  
Author(s):  
Jenő Gacs ◽  
Wuyuan Zhang ◽  
Tanja Knaus ◽  
Francesco G. Mutti ◽  
Isabel W.C.E. Arends ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
Reductive Amination ◽  
Aerobic Oxidation ◽  
Secondary Alcohols ◽  
One Pot ◽  
Enantiomerically Pure ◽  
Step Procedure ◽  
Wide Range ◽  
Aldehydes And Ketones ◽  
One Step

The consecutive photooxidation and reductive amination of various alcohols in a cascade reaction were realized by the combination of a photocatalyst and several enzymes. Whereas the photocatalyst (sodium anthraquinone-2-sulfonate) mediated the light-driven, aerobic oxidation of primary and secondary alcohols, the enzymes (various ω-transaminases) catalyzed the enantio-specific reductive amination of the intermediate aldehydes and ketones. The system worked in a one-pot one-step fashion, whereas the productivity was significantly improved by switching to a one-pot two-step procedure. A wide range of aliphatic and aromatic compounds was transformed into the enantiomerically pure corresponding amines via the photo-enzymatic cascade.

Synthesis and photophysical properties of benzo[c]phenanthrene derivatives

2021 ◽  
Vol 18 ◽  
Author(s):  
Amira K. Hajri ◽  
Marzough A. Albalawi ◽  
Souad A. Moussa ◽  
Faouzi Aloui
Keyword(s):  
Small Molecules ◽  
Photophysical Properties ◽  
Stokes Shift ◽  
Visible Spectrum ◽  
Strong Emission ◽  
Step Procedure ◽  
Polycyclic Aromatic ◽  
One Step ◽  
Conjugated Compounds ◽  
Stokes Shifts

Background: Three polycyclic aromatic hydrocarbons derived from benzo[c]phenanthrene have been synthesized through a one-step procedure involving palladium Suzuki coupling and are characterized by 1 H and 13C NMR, MS and HRMS spectroscopies. Methods: UV-vis absorption and fluorescence properties of these π-conjugated compounds have been evaluated in solutions and strong emission in the blue region of the visible spectrum was noted. Results: The optical spectra of these small polycyclic aromatic compounds are unusual because absorption is entirely in the UV region (λmax = 281-285 nm), yet fluorescence occurs at 410-422 nm. Conclusion: This equates to a Stokes shift of 1.32-1.39 eV (10756-11256 cm−1 ) and is among the large Stokes shifts that have been reported for small molecules, making them promising candidates for optoelectronic applications.

scholarly journals A Wearable Optical Microfibrous Biomaterial with Encapsulated Nanosensors Enables Wireless Monitoring of Oxidative Stress

2020 ◽  
Author(s):  
Mohammad Moein Safaee ◽  
Mitchell Gravely ◽  
Daniel Roxbury
Keyword(s):  
Near Infrared ◽  
Structural Integrity ◽  
Wireless Monitoring ◽  
Step Procedure ◽  
Apparent Loss ◽  
Source Distance ◽  
Wide Range ◽  
One Step ◽  
The Individual ◽  
Walled Carbon Nanotubes

AbstractIn an effort to facilitate personalized medical approaches, the continuous and noninvasive monitoring of biochemical information using wearable technologies can enable a detailed understanding of an individual’s physiology. Reactive oxygen species (ROS) are a class of oxygen-containing free radicals which function in a wide range of biological processes. In wound healing applications, the continuous monitoring of ROS through a wearable diagnostics platform is essential for the prevention of chronicity and pathogenic infection. Here, a versatile one-step procedure is utilized to fabricate optical core-shell microfibrous textiles incorporating single-walled carbon nanotubes (SWCNTs) for the real-time optical monitoring of hydrogen peroxide concentrations in wounds. The environmentally sensitive and non-photobleachable fluorescence of SWCNTs enables continuous analyte monitoring without a decay in signal over time. The existence of multiple chiralities of SWCNTs emitting near-infrared fluorescence with narrow bandwidths allows a ratiometric signal readout invariant to the excitation source distance and exposure time. The individual fibers encapsulate the SWCNT nanosensors for at least 21 days without apparent loss in structural integrity. Moreover, the microfibrous textiles can be utilized to spatially resolve peroxide concentrations on a wound surface using a camera and can be integrated into commercial wound bandages without being altered or losing their optical properties.

Luminescence from individual dislocations in II-VI and III-V semiconductors

1991 ◽  
Vol 49 ◽  
pp. 834-835
Author(s):  
J W Steeds
Keyword(s):  
Group Iv ◽  
Luminescence Properties ◽  
Carrier Recombination ◽  
Transmission Electron ◽  
Wide Range ◽  
Basic Physics ◽  
Semiconducting Compounds ◽  
Diamond Group ◽  
Non Destructive ◽  
Technological Significance

There is a wide range of experimental results related to dislocations in diamond, group IV, II-VI, III-V semiconducting compounds, but few of these come from isolated, well-characterized individual dislocations. We are here concerned with only those results obtained in a transmission electron microscope so that the dislocations responsible were individually imaged. The luminescence properties of the dislocations were studied by cathodoluminescence performed at low temperatures (~30K) achieved by liquid helium cooling. Both spectra and monochromatic cathodoluminescence images have been obtained, in some cases as a function of temperature.There are two aspects of this work. One is mainly of technological significance. By understanding the luminescence properties of dislocations in epitaxial structures, future non-destructive evaluation will be enhanced. The second aim is to arrive at a good detailed understanding of the basic physics associated with carrier recombination near dislocations as revealed by local luminescence properties.

scholarly journals Electrochromic Performance and Capacitor Performance of α-MoO3 Nanorods Fabricated by a One-Step Procedure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 783
Author(s):  
Ying Duan ◽  
Chen Wang ◽  
Jian Hao ◽  
Yang Jiao ◽  
Yanchao Xu ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Average Diameter ◽  
Fast Response ◽  
Cycle Stability ◽  
Electrochromic Devices ◽  
Step Procedure ◽  
One Step ◽  
Supercapacitor Performance ◽  
First Time ◽  
Prepared Nanorods

In this paper, we propose for the first time the synthesis of α-MoO3 nanorods in a one-step procedure at mild temperatures. By changing the growth parameters, the microstructure and controllable morphology of the resulting products can be customized. The average diameter of the as-prepared nanorods is about 200 nm. The electrochromic and capacitance properties of the synthesized products were studied. The results show that the electrochromic properties of α-MoO3 nanorods at 550 nm have 67% high transmission contrast, good cycle stability and fast response time. The MoO3 nanorods also exhibit a stable supercapacitor performance with 98.5% capacitance retention after 10,000 cycles. Although current density varies sequentially, the nanostructure always exhibits a stable capacitor to maintain 100%. These results indicate the as-prepared MoO3 nanorods may be good candidates for applications in electrochromic devices and supercapacitors.

scholarly journals One-step preparation of antimicrobial silicone materials based on PDMS and salicylic acid: insights from spatially and temporally resolved techniques

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Luca Barbieri ◽  
Ioritz Sorzabal Bellido ◽  
Alison J. Beckett ◽  
Ian A. Prior ◽  
Jo Fothergill ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Laser Scanning ◽  
Pathogenic Bacteria ◽  
Pharmaceutical Products ◽  
Laser Scanning Microscopy ◽  
Wound Dressings ◽  
Confocal Laser ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
One Step

AbstractIn this work, we introduce a one-step strategy that is suitable for continuous flow manufacturing of antimicrobial PDMS materials. The process is based on the intrinsic capacity of PDMS to react to certain organic solvents, which enables the incorporation of antimicrobial actives such as salicylic acid (SA), which has been approved for use in humans within pharmaceutical products. By combining different spectroscopic and imaging techniques, we show that the surface properties of PDMS remain unaffected while high doses of the SA are loaded inside the PDMS matrix. The SA can be subsequently released under physiological conditions, delivering a strong antibacterial activity. Furthermore, encapsulation of SA inside the PDMS matrix ensured a diffusion-controlled release that was tracked by spatially resolved Raman spectroscopy, Attenuated Total Reflectance IR (ATR-IR), and UV-Vis spectroscopy. The biological activity of the new material was evaluated directly at the surface and in the planktonic state against model pathogenic bacteria, combining confocal laser scanning microscopy, electron microscopy, and cell viability assays. The results showed complete planktonic inhibition for clinically relevant strains of Staphylococcus aureus and Escherichia coli, and a reduction of up to 4 orders of magnitude for viable sessile cells, demonstrating the efficacy of these surfaces in preventing the initial stages of biofilm formation. Our approach adds a new option to existing strategies for the antimicrobial functionalisation of a wide range of products such as catheters, wound dressings and in-dwelling medical devices based on PDMS.

Peroxidase: a multifunctional enzyme in grapevines

2003 ◽  
Vol 30 (6) ◽  
pp. 577 ◽  
Author(s):  
Alfonso Ros Barceló ◽  
Federico Pomar ◽  
Matías López-Serrano ◽  
Maria Angeles Pedreño
Keyword(s):  
Cell Wall ◽  
Metabolic Regulation ◽  
Trichoderma Viride ◽  
Visible Spectrum ◽  
H2o2 Production ◽  
Class Iii ◽  
Absorption Bands ◽  
Peroxidase Isoenzyme ◽  
Wide Range ◽  
Uv C

Peroxidases are heme-containing enzymes that catalyse the one-electron oxidation of several substrates at the expense of H2O2. They are probably encoded by a large multigene family in grapevines, and therefore show a high degree of polymorphism. Grapevine peroxidases are glycoproteins of high thermal stability, whose molecular weight usually ranges from 35 to 45 kDa. Their visible spectrum shows absorption bands characteristic of high-spin class III peroxidases. Grapevine peroxidases are capable of accepting a wide range of natural compounds as substrates, such as the cell wall protein extensin, plant growth regulators such as IAA, and phenolics such as benzoic acids, stilbenes, flavonols, cinnamyl alcohols and anthocyanins. They are located in cell walls and vacuoles. These locations are in accordance with their key role in determining the final cell wall architecture, especially regarding lignin deposition and extensin insolubilization, and the turnover of vacuolar phenolic metabolites, a task that also forms part of the molecular program of disease resistance. Although peroxidase is a constitutive enzyme in grapevines, its levels are strongly modulated during plant cell development and in response to both biotic and abiotic environmental factors. To gain an insight into the metabolic regulation of peroxidase, several authors have studied how grapevine peroxidase and H2O2 levels change in response to a changing environment. Nevertheless, the results obtained are not always easy to interpret. Despite such difficulties, the response of the peroxidase–H2O2 system to both UV-C radiation and Trichoderma viride elicitors is worthy of study. Both UV-C and T. viride elicitors induce specific changes in peroxidase isoenzyme / H2O2 levels, which result in specific changes in grapevine physiology and metabolism. In the case of T. viride-elicited grapevine cells, they show a particular mechanism for H2O2 production, in which NADPH oxidase-like activities are apparently not involved. However, they offer a unique system whereby the metabolic regulation of peroxidase by H2O2, with all its cross-talks and downstream signals, may be elegantly dissected.

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