Hydrazone derivative of 2-hydroxyquinoline-3-carbaldehyde: an efficient anionic and cationic sensor

2020 ◽  
Vol 98 (12) ◽  
pp. 779-786
Author(s):  
Nilanjan Chakraborty ◽  
Arijit Chakraborty ◽  
Suman Das
Keyword(s):  
Copper Ions ◽  
Oral Care ◽  
Colour Change ◽  
Blue Shift ◽  
Acetonitrile Solution ◽  
Practical Applications ◽  
Light Yellow ◽  
Bluish Green ◽  
Fluoride Detection ◽  
Hydrazone Derivative

A hydrazone (1) based on 2-hydroxyquinoline-3-carbaldehyde was synthesized and its anion and cation detection ability were studied. It could detect both fluoride in acetonitrile selectively among anions and copper ions in semiaqueous medium among cations. The addition of fluoride ion to the acetonitrile solution of the receptor produced a sharp colour change from light yellow to bluish green. The corresponding UV–vis measurements showed a red shift of the band of receptor 1 for fluoride and a blue shift of the band for copper ions. The fluorescence intensity of the receptor 1 got quenched with both fluoride and copper ions. The detection limits for both the ions are in order of micromolar level. The practical applications of fluoride detection were extended to oral care products.

scholarly journals Enzyme Method-Based Microfluidic Chip for the Rapid Detection of Copper Ions

Micromachines ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1380
Author(s):  
Binfeng Yin ◽  
Xinhua Wan ◽  
Changcheng Qian ◽  
A. S. M. Muhtasim Fuad Sohan ◽  
Teng Zhou ◽  
...  
Keyword(s):  
Metal Ions ◽  
Microfluidic Chip ◽  
Limit Of Detection ◽  
Copper Ions ◽  
Practical Applications ◽  
Enzyme Method ◽  
In Series ◽  
High Concentrations ◽  
Biochemical Detection ◽  
Seawater Samples

Metal ions in high concentrations can pollute the marine environment. Human activities and industrial pollution are the causes of Cu2+ contamination. Here, we report our discovery of an enzyme method-based microfluidic that can be used to rapidly detect Cu2+ in seawater. In this method, Cu2+ is reduced to Cu+ to inhibit horseradish peroxidase (HRP) activity, which then results in the color distortion of the reaction solution. The chip provides both naked eye and spectrophotometer modalities. Cu2+ concentrations have an ideal linear relationship, with absorbance values ranging from 3.91 nM to 256 μM. The proposed enzyme method-based microfluidic chip detects Cu2+ with a limit of detection (LOD) of 0.87 nM. Other common metal ions do not affect the operation of the chip. The successful detection of Cu2+ was achieved using three real seawater samples, verifying the ability of the chip in practical applications. Furthermore, the chip realizes the functions of two AND gates in series and has potential practical implementations in biochemical detection and biological computing.

Temperaturabhängiger Farbwechsel bei Larven der grünen Huschspinne Micromata rosea (Sparassidae) / Temperature-Dependent Colour Change in Larvae of the Green Spider Micromata rosea (Sparassidae)

1982 ◽  
Vol 37 (10) ◽  
pp. 1040-1041 ◽  
Author(s):  
Arthur Holl
Keyword(s):  
Absorption Band ◽  
Qualitative Analysis ◽  
Colour Change ◽  
Yolk Protein ◽  
Water Phase ◽  
Temperature Dependent ◽  
Green Colour ◽  
Bluish Green ◽  
Green Solution

Abstract In the green coloured larvae of Micromata rosea but not in adults temperature raise above 29 °C causes immediate colour change: green to bluish-green. Colour change is reversible by temperature decline below 29 °C. Qualitative analysis of the yolk pigment reveals the same biliverdin conjugates (micromatabilin) as previously identified for adult spiders. The bluish-green colour (above 29 °C) re­sults from an absorption band (675-680 nm, water phase, purified solution) modified to that of the green solution (below 29 °C). Presumably, the thermodependent, rever­sible colour change is due to a special yolk protein bond to the micromatabilin chromophor.

Design of Acyl Donor for Environmentally Benign Acylation of Cellulose Using an Ionic Liquid

2019 ◽  
Vol 72 (2) ◽  
pp. 61 ◽  
Author(s):  
Tokio Takeshita ◽  
Akihisa Kitagawa ◽  
Fumiya Yokosu ◽  
Ryo Matsumoto ◽  
Toshiki Nokami ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Uv Irradiation ◽  
Colour Change ◽  
Environmentally Benign ◽  
Acyl Donor ◽  
Dmso Solution ◽  
Base Catalyst ◽  
Strong Base ◽  
Light Yellow ◽  
Convenient Means

Esterification is the most important derivatization to utilise cellulose as a sustainable resource for the materials industry. Homogeneous esterification is generally the most convenient means to achieve this aim. We found that N-methyl-N-(2-methoxyethyl)pyrrolidinium acetate [P1ME][OAc] easily dissolved cellulose. To achieve the environmental benign acylation of cellulose, we attempted to design acyl donor molecules under strong base catalyst-free conditions. It was found that a [P1ME][OAc] solution of cellulose when mixed with 2,2,2-trifluoroethyl benzoates at 80°C afforded the corresponding cellulose benzoate with a perfect (3.0) degree of substitution (DS) value in almost quantitative yield. We also succeeded in preparing 4-[(4-hydroxyphenyl)diazenyl]benzoate or 4-[(4-methoxyphenyl)diazenyl]benzoate of the cellulose with a DS value of 2.38 or 2.67 by the same protocol, respectively; the DMSO solution prepared by the resulting compounds exhibited a photochromic property, although only a slight colour change from light yellow to colourless was obtained by UV irradiation.

scholarly journals Two novel colorimetric probes (5-HMBA-FH and 3-HMBA-FH) based on fluorescein for copper(II) ion detection

2018 ◽  
Vol 96 (12) ◽  
pp. 1037-1045 ◽  
Author(s):  
Guanhong Liu ◽  
Peipei Ren ◽  
Fan Yang ◽  
Xuekai Dou ◽  
Jun Wang ◽  
...  
Keyword(s):  
Infrared Spectrum ◽  
Simultaneous Determination ◽  
Copper Ions ◽  
Colour Change ◽  
High Sensitivity ◽  
Medical Applications ◽  
H Nmr ◽  
Determination Of Copper ◽  
C Nmr

Two novel isomeric colorimetric probes are established for simultaneous determination of copper ions using 2-hydroxy-5-methoxybenzaldehyde fluorescein hydrazone (5-HMBA-FH) and 2-hydroxy-3-methoxybenzaldehyde fluorescein hydrazone (3-HMBA-FH). They are synthesized by reacting fluorescein hydrazide with 2-hydroxy-5-methoxybenzaldehyde and 2-hydroxy-3-methoxybenzaldehyde, respectively, and then characterized by 1H-NMR, 13C-NMR, and infrared spectrum. The addition of copper ions to the solutions of two novel colorimetric probes can generate the obviously peaks at 498 nm in UV–vis absorption spectra along with a rapid colour change from colourless to dark yellow. The detection limits of the method for Cu2+ ion were 3.442 × 10−6 mol/L and 3.682 × 10−6 mol/L separately for 5-HMBA-FH and 3-HMBA-FH, respectively. The additions of other metal ions hardly affect the determination of copper ions. The proposed method was successfully applied to the analysis of Cu2+ ions in various samples. This method possesses high sensitivity, high simplicity, and minimized interference and will provide a great advantage in detecting copper ions in the environment, food, and medical applications.

scholarly journals Theoretical insights into a colorimetric azo-based probe to detect copper ions

RSC Advances ◽  
2020 ◽  
Vol 10 (39) ◽  
pp. 23196-23202
Author(s):  
Juan Pang ◽  
Li Shu ◽  
Ming Li ◽  
Xiaohong Hu
Keyword(s):  
Dft Calculations ◽  
Energy Gap ◽  
Copper Ions ◽  
Colour Change ◽  
Amino Group ◽  
Lumo Energy ◽  
Homo Lumo

DFT calculations indicated that the rotation of the N,N-di(carboxymethyl)amino group around the N–CAr bond by approximately 90°, resulted in a larger HOMO–LUMO energy gap, and led to the observed colour change.

Synthesis and characterization of triphenylamine-based polymers and their application towards solid-state electrochromic cells

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 78984-78993 ◽  
Author(s):  
Jaemyeng Jeong ◽  
Rangaraju Satish Kumar ◽  
Mergu Naveen ◽  
Young-A. Son
Keyword(s):  
Solid State ◽  
Color Change ◽  
Synthesis And Characterization ◽  
Light Blue ◽  
Light Yellow ◽  
Bluish Green ◽  
Dark Green

Triphenyl amine based new molecules have synthesized for electrochromic cells. We achieved color change forPJK1, orange to dark green; forPJK2, light yellow to reddish brown; forPJK3, light blue to grey; and forPJK4, green to bluish green.

Porifera, one new species Suberea purpureaflava n. sp. (Demospongiae, Verongida, Aplysinellidae) from northern Red Sea coral reefs, with short descriptions of Red Sea Verongida and known Suberea species

Zootaxa ◽  
2011 ◽  
Vol 2994 (1) ◽  
pp. 60 ◽  
Author(s):  
JOCHEN GUGEL ◽  
MARIT WAGLER ◽  
FRANZ Brümmer
Keyword(s):  
New Species ◽  
Coral Reefs ◽  
Red Sea ◽  
Colour Change ◽  
Gulf Of Aqaba ◽  
Light Yellow ◽  
Dark Violet ◽  
One New Species ◽  
Northern Red Sea

A new verongid sponge (Suberea purpureaflava n. sp.) is described from Dahab, Gulf of Aqaba, in the northern Red Sea. It has a pronounced colour change (a dark red ectosome with whitish pore sieves and a light yellow choanosome in the living specimen changes to a uniform dark violet in the fixed state) and rather rare dendritic fibres with pith and bark and a diameter of about 110–165µm, with the pith occupying 80–90 % of the fibre. Especially the pore sieves were very striking in situ. The new species is compared to all verongid sponges so far recorded from the Red Sea and to all known and accepted Suberea species worldwide. An identification key to all known Suberea species is given. This new species record brings the number of Suberea species described to a total of 11.

scholarly journals Colour Stability of Veneering Composites after Accelerated Aging

2010 ◽  
Vol 04 (02) ◽  
pp. 137-142 ◽  
Author(s):  
Triantafillos Papadopoulos ◽  
Aspasia Sarafianou ◽  
Andreas Hatzikyriakos
Keyword(s):  
Colour Change ◽  
Accelerated Aging ◽  
Blue Shift ◽  
Colour Stability ◽  
Before And After ◽  
Indirect Composites ◽  
Colour Changes ◽  
Indirect Composite ◽  
The Mean ◽  
One Way Anova

Objectives: To investigate the colour stability of four indirect composite restorative materials after accelerated aging.Methods: Four indirect composites (Gradia, Signum+, HFO and Adoro) were used. For each material, six specimens were prepared and subjected to accelerated aging (Suntest CPS+, Atlas, Chicago, IL, USA) according to ISO 7491. A Dr. Lange Microcolor Data Station colorimeter (Braive Instruments, Liege, Belgium) was used to measure specimen colour before and after aging. Measurements were performed according to the CIE L*a*b* system, and the mean L*, a* and b* values for each material were calculated. The equation ΔΕ = [(ΔL*)2 + (Δa*)2 + (Δb*)2]1/2 was used to measure the total colour change (ΔΕ), where ΔL*, Δa* and Δb* are the differences in the respective values before and after aging. One-way ANOVA were used to determine statistically significant differences in ΔL*, Δa*, Δb* and ΔΕ.Results: No statistically significant differences were found in ΔL*, Δa*, Δb* and ΔΕ among the materials tested (PΔL*=.063; PΔa*=.521; PΔb*=.984 and PΔE=.408). After aging, Gradia specimens showed an increase in lightness (ΔL*=0.36) and a green-yellow shift (Δa*=-1.18, Δb*=0.6), while Signum+ specimens exhibited an increase in lightness (ΔL*=0.5) and a green-blue shift (Δa*=-0.9, Δb*=- 0.45). HFO specimens exhibited an increase in lightness (ΔL*=0.75) and a green-yellow shift (Δa*=- 1.3, Δb*=0.06), and Adoro specimens exhibited an increase in lightness (ΔL*=2.07) and a green-yellow shift (Δa*=-1.3, Δb*=0.68).Conclusions: Colour changes were found to be within accepted values of perceptibility and clinical acceptance after accelerated aging, and no statistically significant differences were found in ΔL*, Δa*, Δb* and ΔΕ among the materials tested. (Eur J Dent 2010;4:137-142)

scholarly journals Degradation dynamics of quantum dots in white LED applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hsiao-Chien Chen ◽  
Abdul Shabir ◽  
Cher Ming Tan ◽  
Preetpal Singh ◽  
Jia-Hung Lin
Keyword(s):  
Quantum Dots ◽  
Light Intensity ◽  
White Light ◽  
Density Functional ◽  
Light Emission ◽  
Green Light ◽  
Blue Shift ◽  
Practical Applications ◽  
Initial Stage ◽  
Green Light Emission

AbstractQuantum Dots (QDs) are being investigated in a hybrid white light LED structure which inculcates phosphor in the package with a blue LED chip as the light source recently. In this work, Zn doped CdS QD with ZnS shell together with green light emission phosphor is used. Upon prolonged operation, degradation of the LEDs due to the degradation of QDs is observed, which can limit its practical applications. The degradation includes intensity reduction as well as blue shift of the emitted wavelength from the white light. Three stages of degradation are observed, namely an enhancement state where light intensity is found to increase, followed by a rapid degradation stage where light intensity decreases rapidly, and finally a slower degradation stage where the degradation rate of light intensity slows down and continues till the end of the test. Through various detail material analysis, with confirmation from the density functional theory (DFT) calculations, we find that the degradation of the LEDs is due to the time evolving degradation of CdS core structure, beginning from the oxidation of sulfur vacancy of CdS QDs by the nearby oxygen atoms as a result of imperfection of the ZnS protective coating around the QDs in the presence of blue light. This oxidation renders a transformation of CdS into CdO at the initial stage. The final stage is the formation of CdSO4 via some intermediate processes.

The mineralogy of metamorphosed basic rocks from the Willyama Complex, Broken Hill district, New South Wales. Part I. Hornblendes

1965 ◽  
Vol 35 (270) ◽  
pp. 306-326 ◽  
Author(s):  
R. A. Binns
Keyword(s):  
Colour Change ◽  
Titanium Content ◽  
Steady Increase ◽  
Lower Grade ◽  
Broken Hill ◽  
South Wales ◽  
Bluish Green ◽  
Hill District ◽  
Structural Formulae ◽  
Basic Rocks

SummaryThe typical hornblendes of metabasic rocks in the Willyama Complex change from bluish-green to deeply coloured brownish varieties with increase in metamorphic grade. Chemical analyses and optical properties of 23 representative hornblendes are interpreted as showing this colour change to reflect steady increase in titanium content of the hornblendes with increase in grade. High-grade hornblendes also differ from those of lower grade in that tetrahedral aluminium in the Z sites is balanced to an increased extent by alkalis entering the A site rather than by octahedral aluminium entering the Y site. Comparison between theoretical and measured densities of Willyama hornblendes suggest that a calculation based on 23 oxygen anion provides closer approximations than a 24 (O, OH, F) calculation to their structural formulae.

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