scholarly journals A Highly Water-Soluble Fluorescent and Colorimetric pH Probe

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 83 ◽  
Author(s):  
Rosita Diana ◽  
Ugo Caruso ◽  
Angela Tuzi ◽  
Barbara Panunzi
Keyword(s):  
Ph Value ◽  
Condensation Reaction ◽  
Ph Sensor ◽  
Water Soluble ◽  
Alkaline Solutions ◽  
Planar Geometry ◽  
Ph Titration ◽  
Ph Probe ◽  
Hydrogen Bonding Pattern ◽  
Colorimetric Response

A new 5-(4-((2-(benzothiazole-2-carbonyl)hydrazono)methyl)-3-hydroxyphenoxy)-N,N,N-trimethylpentan-1-aminium bromide (BTABr) fluorescent and colorimetric pH probe was easily synthesized by the condensation reaction of benzothiazole-2-carbohydrazide with 5-(4-formyl-3-hydroxyphenoxy)-N,N,N-trimethylpentan-1-aminium bromide. The benzothiazole moiety provided the emissive part of the molecule and the charged trimethyl amino group guaranteed outstanding solubility in water, for an organic molecule. pH titration experiments indicated that the probe is useful for monitoring acidic and alkaline solutions, turning reversibly in color/fluorescence just at a neutral pH value. Naked-eye colorimetric response was observed both in solution and in the solid state. In addition, the probe showed high stability and selectivity and large Stokes shifts. Because of these features, BTABr can potentially work as an on-off real-time pH sensor for intracellular pH imaging. The crystal structure of BTABr examined by single-crystal analysis showed a planar geometry of the molecule and confirmed the presence of a molecular stacking between molecules joined in a complex tridimensional hydrogen bonding pattern.

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

scholarly journals One-Pot Microwave-Assisted Synthesis of Water-Soluble Pyran-2,4,5-triol Glucose Amine Schiff Base Derivative: XRD/HSA Interactions, Crystal Structure, Spectral, Thermal and a DFT/TD-DFT

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
Yousef Hijji ◽  
Rajeesha Rajan ◽  
Hamdi Ben Yahia ◽  
Said Mansour ◽  
Abdelkader Zarrouk ◽  
...  
Keyword(s):  
Schiff Base ◽  
Molecular Orbital ◽  
Density Functional ◽  
Condensation Reaction ◽  
3D Structure ◽  
Water Soluble ◽  
Microwave Assisted Synthesis ◽  
One Pot ◽  
Microwave Assisted ◽  
Td Dft

The(3R,4R,6R)-3-(((E)-2-hydroxybenzylidene)amino)-6-(hydroxymethyl)tetrahydro-2H-pyran-2,4,5-triol water-soluble Glucose amine Schiff base (GASB-1) product was made available by condensation of 2-hydroxybenzaldehyde with (3R,6R)-3-amino-6-(hydroxymethyl)-tetra-hydro-2H-pyran-2,4,5-triol under mono-mode microwave heating. A one-pot 5-minute microwave-assisted reaction was required to complete the condensation reaction with 90% yield and without having byproducts. The 3D structure of GASB-1 was solved from single crystal X-ray diffraction data and computed by DFT/6-311G(d,p). The Hirshfeld surface analysis (HSA), molecular electronic potential (MEP), Mulliken atomic charge (MAC), and natural population analysis (NPA) were performed. The IR and UV-Vis spectra were matched to their density functional theory (DFT) relatives and the thermal behavior was resolved in an open-room condition via thermogravimetry/Derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC). The highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO), density of state (DOS), and time-dependence TD-DFT computations were correlated to the experimental electron transfer in water and acrylonitrile solvents.

scholarly journals Effects of Sugar Cane Molasses Addition on the Fermentation Quality, Microbial Community, and Tastes of Alfalfa Silage

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 355
Author(s):  
Runbo Luo ◽  
Yangdong Zhang ◽  
Fengen Wang ◽  
Kaizhen Liu ◽  
Guoxin Huang ◽  
...  
Keyword(s):  
Sugar Cane ◽  
Ph Value ◽  
Electronic Tongue ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Cane Molasses ◽  
Fermentation Quality ◽  
Alfalfa Silage ◽  
Additive Control

The objective was to study the effects of sugar cane molasses addition on the fermentation quality and tastes of alfalfa silage. Fresh alfalfa was ensiled with no additive (Control), 1% molasses (M1), 2% molasses (M2), and 3% molasses (M3) for 206 days. The chemical composition and fermentation characteristics of the alfalfa silages were determined, the microbial communities were described by 16S rRNA sequencing, and the tastes were evaluated using an electronic tongue sensing system. With the amount of added molasses (M), most nutrition (dry matter and crude protein) was preserved and water-soluble carbohydrates (WSC) were sufficiently used to promote the fermentation, resulting in a pH reduction from 5.16 to 4.48. The lactic acid (LA) content and LA/acetic acid (AA) significantly increased, indicating that the fermentation had turned to homofermentation. After ensiling, Enterococcus and Lactobacillus were the dominant genus in all treatments and the undesirable microbes were inhibited, resulting in lower propionic acid (PA), butyric acid (BA), and NH3-N production. In addition, bitterness, astringency, and sourness reflected tastes of alfalfa silage, while umami and sourness changed with the amount of added molasses. Therefore, molasses additive had improved the fermentation quality and tastes of alfalfa silage, and the M3 group obtained the ideal pH value (below 4.5) and the best condition for long-term preservation.

scholarly journals Characterizing Wool Keratin

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jeanette M. Cardamone ◽  
Alberto Nuñez ◽  
Rafael A. Garcia ◽  
Mila Aldema-Ramos
Keyword(s):  
Hydrogen Peroxide ◽  
Gel Electrophoresis ◽  
Water Soluble ◽  
Alkaline Solutions ◽  
Biodegradable Material ◽  
Alkaline Hydrogen Peroxide ◽  
Cortical Cells ◽  
Sds Page ◽  
Fibrous Matrices ◽  
Wool Keratin

Keratin from wool is a reactive, biocompatible, and biodegradable material. As the biological structural component of skin (soft keratins) and of nails, claws, hair, horn, feathers, and scales (hard keratins) pure keratin comprises up to 90% by weight of wool. Wool was treated in alkaline solutions to extract from 68% to 82% keratin within 2 to 5 hours of exposure at . The keratin products were water-soluble and were confirmed to contain intermediate filament and microfibrillar component-proteins of fractured, residual cuticle, and cortical cells. Oxidation of wool by peroxycarboximidic acid in alkaline hydrogen peroxide produced keratin products with distinct microcrystalline structures: descaled fibers, fibrous matrices, and lyophilized powders. Morphology and confirmation of peptide functionality were documented by SEM, Amino Acid Analysis, SDS-PAGE gel electrophoresis, MALDI-TOF/TOF, and FTIR analyses. The reactivity of keratin from wool models the reactivity of keratin from low-value sources such as cattle hair.

scholarly journals Development of a Stability Indicating Method for Simultaneous Analysis of Five Water-Soluble Vitamins by Liquid Chromatography

2018 ◽  
Vol 3 (4) ◽  
pp. 207-218 ◽  
Author(s):  
Mouloud Yessaad ◽  
Lise Bernard ◽  
Daniel Bourdeaux ◽  
Philip Chennell ◽  
Valérie Sautou
Keyword(s):  
Liquid Chromatography ◽  
Degradation Products ◽  
Pharmaceutical Preparations ◽  
Water Soluble ◽  
Alkaline Solutions ◽  
Array Detector ◽  
Forced Degradation ◽  
Metaphosphoric Acid ◽  
Stability Indicating ◽  
Stability Indicating Method

Abstract Background Water-soluble vitamins are often included simultaneously in pharmaceutical formulations as food complements or in parenteral nutrition mixtures. Given their sensitivity to heat, light or pH variations, it is important to study their stability using validated stability indicating methods. We thus aimed to validate a liquid chromatography (LC) stability-indicating method for the simultaneous quantification of 5 water-soluble vitamins. Methods We analyzed four water-soluble B vitamins (nicotinamide, pyridoxine, folic acid, cyanocobalamin) and ascorbic acid using a LC method with diode array detector. They were separated on a C18 stationary phase under gradient elution of solvent A [0.2 % of metaphosphoric acid in water and acetonitrile 98:2] and solvent B (100 % acetonitrile). All vitamins were subjected to forced degradation conditions and we showed that the obtained degradation products didn’t interfere with the vitamins. Results The method allows the separation of the 5 water-soluble vitamins in a 30 minute run without any interference from the breakdown products obtained with acid/alkaline solutions, hydrogen peroxide, temperature and light. It meets all the qualitative and quantitative criteria for validation with an acceptable accuracy and good linearity. Conclusions This stability-indicating method can be used for carrying out stability studies of water-soluble vitamins in pharmaceutical preparations.

STUDY ON TIME-CONSTANT MODELS OF SnO2pH SENSOR

2009 ◽  
Vol 21 (06) ◽  
pp. 449-452
Author(s):  
Chi-Wei Chen ◽  
Jung-Chuan Chou ◽  
Tai-Ping Sun ◽  
Shen-Kan Hsiung
Keyword(s):  
Time Constant ◽  
Electrochemical Impedance ◽  
Ph Value ◽  
Ph Sensor ◽  
Membrane Resistance ◽  
Hysteresis Effect ◽  
Equivalent Model ◽  
Resistance Change ◽  
Ph Buffer ◽  
Function Relationship

The aim of this study was to discuss the hysteresis effect of SnO2 pH sensor based on separative extended gate field effect transistor (SEGFET). Based on the theorem of three time-constants model, hysteresis model is linked with drift effect. Function relationship of pH value and time constant is also derived from the drift effects with difference pH value. Besides, electrochemical impedance spectroscopy (EIS) is utilized to interpret the mechanism of hysteresis effect. Experiments of EIS are carried out in different pH buffer solutions. An equivalent model of sensing membrane is obtained by theorem of EIS. The experimental results indicate that the equivalent circuit elements, such as membrane capacitance and membrane resistance, change with pH. This phenomenon is compared with other literatures and discussed on hysteresis effect.

scholarly journals Development of a Low-Cost pH Meter for Liquid Chemical Fertilizers

2020 ◽  
Vol 8 (4) ◽  
pp. 840-846
Author(s):  
Muhittin Yağmur Polat ◽  
Abdullah Beyaz ◽  
İbrahim Çilingir
Keyword(s):  
Ph Value ◽  
Low Cost ◽  
Ph Sensor ◽  
Field Application ◽  
Average Error ◽  
Chemical Fertilizers ◽  
Modern Agriculture ◽  
Ph Values ◽  
Water Ph ◽  
Liquid Chemical

Liquid chemical fertilizers are widely used in modern agriculture. The pH values of these fertilizers are important in terms of their effectiveness in the field application and their effect on the soil-water pH balance. Therefore, it is necessary to measure the pH and other properties of liquid fertilizers with fast, practical and inexpensive methods. With the advancing technology, pH value has been started to measure more accurately and efficiently with the help of low-cost devices. In this study, a low-cost pH meter was developed using a low-cost pH sensor, an Arduino UNO R3 microcontroller board, and a software written in the C/C++ programming language. The developed pH meter was used to measure the pH values of liquid chemical fertilizers. Close variations were observed between the values obtained from it and the values measured by an accredited, laboratory-type pH meter. According to the pH measurements of the two pH meters, R2 ranged 88.1% to 99.3%, average error range 0.14 to 0.28, and average error percentage ranged 1.56% to 6.81% for three different types of liquid fertilizers. In light of these results, it was shown that the developed low-cost pH meter can be useful for practical pH measurement applications.

scholarly journals The effect of bacterial inoculant supplementation on the fermentation process of crushed maize ears in laboratory silos

2005 ◽  
Vol 53 (4) ◽  
pp. 33-42
Author(s):  
Petr Doležal ◽  
Dušan Kořínek ◽  
Jan Doležal ◽  
Václav Pyrochta
Keyword(s):  
Lactic Acid ◽  
Ph Value ◽  
Lactobacillus Rhamnosus ◽  
Lactobacillus Brevis ◽  
Water Soluble ◽  
Bacterial Strains ◽  
Total Acid ◽  
Ethanol Content ◽  
Fermentation Quality ◽  
Biological Additive

In the experiment was the effect of biological additive on the fermentation quality of crushed maize ears of two hybrids by comparing with the untreated control. The bacterial inoculant „A“ contained selected bacterial strains of Lactobacillus rhamnosus (NCIMB 30121) and Enterococcus faecium (NCIMB 30122). As effective substances of bacterial water–soluble inoculant „B“ were selected bacterial strains of Lactobacillus rhamnosus (NCIMB 30121), Lactobacillus plantarum (DSM 12836), Lactobacillus brevis (DSM 12835), Lactobacillus buchneri (DSM 12856), Pediococcus acidialactici (P. pentosaceus) (DSM 12834). The addition of inoculant „A“ in our experiment conditions increased statistically significantly (P<0.01) the pH value (4.09±0.01), resp. 4.02±0.02 in second trial with Pedro hybrid. The bacterial inoculant „B“ increased significantly (P<0.01) the contents of lactic acid (50.95±0.1.87 g/kg DM), acetic acid (18.61±0.34 g/kg DM), sum of acids (69.55±1.62 g/kg DM) and decreased (P<0.01) in the first trial the ethanol content (5.41±0.45 g/kg DM). The highest DM content (P<0.01) was in all experimental inoculated silages with additive „A“ (54.26±0.86%, and 53.56±0.54%, resp.). The bacterial inoculant „A“ increased significantly (P<0.01) in comparison with control silage in the second trial the content of lactic acid (34.66Ī2.81 g/kg DM), sum of acids (44.68±3.54 g/kg DM), the total acids content (32.87±2.88 g/kg DM), and ethanol content (17.33±0.79 g/kg DM). The inoculation positive effect was demonstrated in reduction of ethanol amount and of total acid production. The pH value of inoculated silages was not significantly lower than that in the control silage.

scholarly journals Systematic Evaluation of Arduino Open Source for Automation and Control of Chemical Processes

2020 ◽  
Vol 10 (2) ◽  
pp. 2258-2271
Keyword(s):  
Open Source ◽  
Chemical Process ◽  
Ph Value ◽  
Low Cost ◽  
Ph Sensor ◽  
Chemical Processes ◽  
Systematic Evaluation ◽  
Feedback Signal ◽  
Automation And Control ◽  
And Control

Inceptions for chemical process automation are presented in this study. A chemical process demonstrated by neutralization reaction was designed, built, and tested experimentally towards evaluating automation and control algorithms through the Arduino Mega platform. The main objective parameter in this work was selected to be the product pH value, which was evaluated based on several scenarios that targeted various changes in direct and indirect effects. Two main branched ideas were investigated in this study; the first was dealt with the application of Arduino board in the automation of chemical process; the second was dedicated to studying integration of Arduino board in controlling the targeted pH parameter in the product side. Upon examining different automation scenarios, an algorithm was developed to approach the product quality of specific pH and temperature efficiently. The automation algorithm was further developed by integrating the process dynamics and control concepts towards speeding up the pH set point's reach. To make this happen, the pump's speed was corrected and tuned based on the feedback signal from the pH sensor. Consequently, the setpoint was reached in shorter periods, attaining considerable savings in time (≈ 35%). Based on the study outcomes, it is believed that Arduino open source is a challenging and promising low-cost platform, proved useful for mimicking control and automation of chemical processes.

scholarly journals TiO2 Nano Flowers Based EGFET Sensor for pH Sensing

Coatings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 251
Author(s):  
Chih-Chiang Yang ◽  
Kuan-Yu Chen ◽  
Yan-Kuin Su
Keyword(s):  
Ph Value ◽  
Ph Sensor ◽  
High Sensitivity ◽  
Experimental Result ◽  
Ph Sensing ◽  
Voltage Reference ◽  
Ph Sensors ◽  
Oxide Substrate ◽  
Ph Range ◽  
The Relationship

In this study, pH sensors were successfully fabricated on a fluorine-doped tin oxide substrate and grown via hydrothermal methods for 8 h for pH sensing characteristics. The morphology was obtained by high-resolution scanning electron microscopy and showed randomly oriented flower-like nanostructures. The TiO2 nanoflower pH sensors were measured over a pH range of 2–12. Results showed a high sensitivity of the TiO2 nano-flowers pH sensor, 2.7 (μA)1/2/pH, and a linear relationship between IDS and pH (regression of 0.9991). The relationship between voltage reference and pH displayed a sensitivity of a 46 mV/pH and a linear regression of 0.9989. The experimental result indicated that a flower-like TiO2 nanostructure extended gate field effect transistor (EGFET) pH sensor effectively detected the pH value.

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