Phenolphthalein Research Articles

Self-Assembled Chromogenic Polymeric Nanoparticle-Laden Nanocarrier as a Signal Carrier for Derivative Binary Responsive Virus Detection

In the current biosensor, the signal generation is limited to single virus detection in the reaction chamber. An adaptive strategy is required to enable the recognition of multiple viruses for diagnostics and surveillance. In this work, a nanocarrier is deployed to bring specific signal amplification into the biosensor, depending on the target viruses. The nanocarrier is designed using pH-sensitive polymeric nanoparticle-laden nanocarriers (PNLNs) prepared by sequential nanoprecipitation. The nanoprecipitation of two chromogens, phenolphthalein (PP) and thymolphthalein (TP), is investigated in three different solvent systems in which PNLNs demonstrate a high loading of the chromogen up to 59.75% in dimethylformamide (DMF)/dimethyl sulfoxide (DMSO)/ethanol attributing to the coprecipitation degree of the chromogens and the polymer. The PP-encapsulated PNLNs (PP@PNLNs) and TP-encapsulated PNLNs (TP@PNLNs) are conjugated to antibodies specific to target viruses, influenza virus A subtype H1N1 (IV/A/H1N1) and H3N2 (IV/A/H3N2), respectively. After the addition of anti-IV/A antibody-conjugated magnetic nanoparticles (MNPs) and magnetic separation, the enriched PNLNs/virus/MNPs sandwich structure is treated in an alkaline solution. It demonstrates a synergy reaction in which the degradation of the polymeric boundary and the pH-induced colorimetric development of the chromogen occurred. The derivative binary biosensor shows feasible detection on IV/A with excellent specificities of PP@PNLNs on IV/A/H1N1 and TP@PNLNs on IV/A/H3N2 with LODs of 27.56 and 28.38 fg mL-1, respectively. It intrigues the distinguished analytical signal in human serum with a variance coefficient of 25.8% and a recovery of 93.6-110.6% for one-step subtype influenza virus detection.

Colorimetric LPMO assay with direct implication for cellulolytic activity

BackgroundLytic polysaccharide monooxygenases (LPMOs) are important industrial enzymes known for their catalytic degradation of recalcitrant polymers such as cellulose or chitin. Their activity can be measured by lengthy HPLC methods, while high-throughput methods are less specific. A fast and specific LPMO assay would simplify screening for new or engineered LPMOs and accelerate biochemical characterization.ResultsA novel LPMO activity assay was developed based on the production of the dye phenolphthalein (PHP) from its reduced counterpart (rPHP). The colour response of rPHP oxidisation catalysed by the cellulose-specific LPMO from Thermoascus aurantiacus (TaAA9A), was found to increase tenfold by adding dehydroascorbate (DHA) as a co-substrate. The assay using a combination of rPHP and DHA was tested on 12 different metallo-enzymes, but only the LPMOs catalysed this reaction. The assay was optimized for characterization of TaAA9A and showed a sensitivity of 15 nM after 30 min incubation. It followed apparent Michaelis–Menten kinetics with kcat = 0.09 s−1 and KM = 244 µM, and the assay was used to confirm stoichiometric copper–enzyme binding and enzyme unfolding at a temperature of approximately 60 °C. DHA, glutathione and fructose were found to enhance LPMO oxidation of rPHP and in the optimized assay conditions these co-substrates also enabled cellulose degradation.ConclusionsThis novel and specific LPMO assay can be carried out in a convenient microtiter plate format ready for high-throughput screening and enzyme characterization. DHA was the best co-substrate tested for oxidation of rPHP and this preference appears to be LPMO-specific. The identified co-substrates DHA and fructose are not normally considered as LPMO co-substrates but here they are shown to facilitate both oxidation of rPHP and degradation of cellulose. This is a rare example of a finding from a high-throughput assay that directly translate into enzyme activity on an insoluble substrate. The rPHP-based assay thus expands our understanding of LPMO catalysed reactions and has the potential to characterize LPMO activity in industrial settings, where usual co-substrates such as ascorbate and oxygen are depleted.

Sensitive determination of hydrazine using poly(phenolphthalein), Au nanoparticles and multiwalled carbon nanotubes modified glassy carbon electrode.

This study reports a detailed analysis of an electrode material containing poly(phenolphthalein), carbon nanotubes and gold nanoparticles which shows superior catalytic effect towards to hydrazine oxidation in Britton–Robinson buffer (pH 10.0). Glassy carbon electrode was modified by electropolymerization of phenolphthalein (PP) monomer (poly(PP)/GCE) and the multiwalled carbon nanotubes (MWCNTs) was dropped on the surface. This modified surface was electrodeposited with gold nanoparticles (AuNPs/CNT/poly(PP)/GCE). The fabricated electrode was analysed the determination of hydrazine using cyclic voltammetry, linear sweep voltammetry and amperometry. The peak potential of hydrazine oxidation on bare GCE, poly(PP)/GCE, CNT/GCE, CNT/poly(PP)/GCE, and AuNPs/CNT/poly(PP)/GCE were observed at 596 mV, 342 mV, 320 mV, 313 mV, and 27 mV, respectively. A shift in the overpotential to more negative direction and an enhancement in the peak current indicated that the AuNPs/CNT/poly(PP)/GC electrode presented an efficient electrocatalytic activity toward oxidation of hydrazine. Modified electrodes were characterized with High-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). Amperometric current responses in the low hydrazine concentration range of 0.25–13 µM at the AuNPs/CNT/poly(PP)/GCE. The limit of detection (LOD) value was obtained to be 0.083 µM. A modified electrode was applied to naturel samples for hydrazine determination.

Manufacturing surface active shell and bisphenol A free thermochromic acrylic microcapsules for textile applications

Preparation and characterization of some new thermochromic microcapsules with surface reactivity, material safety and their incorporation to cotton, and wool fabrics were performed in this work. Poly(methyl methacrylate-co-methacrylic acid) P(MMA-co-MAA) was the shell of microencapsulated thermochromic system (TS). The TS acting as a core substance consisted of n-tetradecanol (TD) as solvent, crystal violet lactone (CVL) as a leuco dye and phenolphthalein (PP) as color developer. Particle photographs and average size distribution were evaluated using scanning electron microscopy (SEM) and particle size instruments, respectively. Microcapsules morphology was spherical and particle size average was 13.67 μm. Thermal treatment for thermophysical properties and degradation were performed by using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). DSC and TGA results indicated that microcapsules absorbed 203.6 J/g of latent heat and had good thermal stability for textile applications. Meanwhile, microcapsules had thermo-regulation property due to phase changing of the TD solvent, which was a solvent component of TS. Microencapsulation of TS into P(MMA-co-MAA) shell was proven by Fourier transform infrared (FTIR) spectroscopy. For thermally stimulated color change determination, UV-visible spectroscopy analysis and photographs taken at 25°C and 50°C were used during temperature increase. Some cotton and wool fabrics imparted microcapsules were prepared by exhaustion technique. The heat absorbance capacities of fabrics during melting were measured as 68.2 J/g for cotton fabric and 72.5 J/g for wool fabric. From T-history measurements, it was resulted that fabrics exhibited cooling and heating effect owing to the released or absorbed latent heat by TD. The color measurements based on CIELab system and photographs of fabrics taken at different temperatures showed that color of fabrics transformed from blue to colorless with increasing temperature. It was seen that the synthesized bifunctional thermochromic and energy storing microcapsules had great potential for production of textile materials, which served as reversible color change and thermal indicator.

Carbodiimide coupling versus click chemistry for nanoparticle surface functionalization: A comparative study for the encapsulation of sodium cholate by cellulose nanocrystals modified with β-cyclodextrin

Grafting beta-cyclodextrin (β-CD) onto cellulose nanocrystals (CNC) with the formation of well-dispersed nanoparticles (CNC-CD) and understanding their physicochemical properties are appealing but still challenging in controlled-release applications. Two immobilization methods were proposed and examined in this study; (i) copper (I) catalyzed click chemistry (CuACC) and (ii) carbodiimide coupling. Fourier-transform infrared spectroscopy (FTIR), UV–vis, elementary analysis, contact angle measurements, and thermogravimetric analysis (TGA) were conducted to elucidate the surface modifications. Phenolphthalein (PHTH) titration was used to quantify the grafting efficiency of β-CD on the CNC surface. The carbodiimide coupling in dimethyl sulfoxide was effective to introduce the highest amounts of β-CD (0.17 mmol/g sample) to the CNC in this study. The encapsulation process of bile surfactant, sodium cholate (NaC) was investigated by isothermal titration calorimeter (ITC), and the thermodynamic parameters were determined. The “molecular docking” brought by β-CD offers possible new applications of this sustainable nanohybrid system in the environmental, biomedical and pharmaceutical sectors.

Dialdehyde-β-cyclodextrin-crosslinked carboxymethyl chitosan hydrogel for drug release

A simple method was proposed for preparing the dialdehyde-β-cyclodextrin (DA-β-CD) cross-linked carboxymethyl chitosan (CMCS) hydrogels for drug delivery. DA-β-CD was yielded from the sodium periodate oxidation of β-CD. Phenolphthalein (PhP) was adopted as a model drug to study the drug loading and releasing properties of the obtained hydrogels. The results show that the ability of the hydrogel to load drug is affected by the aldehyde content of DA-β-CD. The inclusion constant of DA-β-CD toward PhP is lower than that of the original β-CD and decreased with the rising of the aldehyde content. An increased cross-linking degree between DA-β-CD and CMCS slows the PhP release to some extent. In comparison with glyoxal/CMCS, DA-β-CD/CMCS presents better PhP release properties. Only 19.2 % of PhP loaded in glyoxal/CMCS was released within 24 h. Half of PhP loaded in DA-β-CD/CMCS was released in 2 h and about 90 % was released within 12 h.

Study on Preparation and Separation and Adsorption Performance of Knitted Tube Composite β-Cyclodextrin/Chitosan Porous Membrane.

In order to obtain membranes with both organic separation and adsorption functions, knitted tube composite β-cyclodextrin/chitosan (β-CD/CS) porous membranes were prepared by the non-solvent induced phase separation (NIPS) method using CS and β-CD as a membrane-forming matrix, glutaraldehyde as crosslinking agent to improve water stability, and knitted tube as reinforcement to enhance the mechanical properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle, water flux, bovine serum albumin (BSA) rejection and tensile test were carried out. The FTIR demonstrated that the β-CD and CS had been successfully crosslinked. With the crosslinking time increased, the membrane structure became denser, the contact angle and the rejection rate increased, while the water flux decreased. The strength and elongation at a break were 236 and 1.7 times higher than these of bare β-CD/CS porous membranes, respectively. The strength of crosslinking membranes increased further. The adsorption performance of composite membranes was investigated for the removal of phenolphthalein (PP) from aqueous solution. The adsorption process followed the Langmuir isotherm model, and the kinetic behavior was accorded with the Double constant equation and the Elovich equation. The adsorption mechanism could be explained by the synergistic effect of host-guest interaction from β-cyclodextrin, non-uniform diffusion and porous network capture.

Insertion of a Cardo Structure into a Polyurethane Framework Using a pH Indicator and Its Impact on Tensile and Shape Memory Properties

Perpendicular cardo structural units were inserted into a polyurethane (PU) framework from the pH indicator (phenolphthalein (PP), phenol red (PR), or bromocresol green (BG)) sharing a triphenylmethyl group. The thermal transitions, mechanical properties, pH-sensitive color change, and low temperature flexibility of the PU modified with the cardo structural units were compared with those of the ordinary PU. Slight cross-linking between PU chains was performed because the insertion of the indicator moieties deteriorated the mechanical properties. The breaking tensile stress and shape recovery capability at 0 °C of the BG-PU series surpassed those of the PP-PU and PR-PU series. The inserted pH indicator moieties did not show the color change under different pH conditions because the isomerization under basic conditions was blocked. Among the three series of PUs, the BG-PU demonstrated the best low temperature flexibility compared with that of the PP-PU and PR-PU due to the functional groups on the phenyl rings of BG. Insertion of a cardo structural unit from the pH indicator reduced the molecular interaction between PU chains.

High‐performance soluble copolyarylate based on phenolphthalein: synthesis, characterization and properties

AbstractA series of copolyarylates (PP0–PP100) containing phthalide groups was synthesized via interfacial polymerization from a mixture of phenolphthalein (PP) and bisphenol A with molar equivalent of terephthalyl chloride. Incorporating PP into the polymer chain improved the solubility of the polyarylates in common organic solvents. The glass transition temperature (191–314 °C), residual weight percentage, Young's modulus (1.7–2.8 GPa), solubility and complex melt viscosity of the copolyarylates increased with increasing PP units in the copolymerization. By contrast, crystallinity and elongation at break (14.1 to 11.2%) of the copolyarylates decreased with increasing PP units in the polymer backbone. When the PP content increased over 30 mol% (PP30), the copolyarylates became amorphous polymers. When the PP content was below 30 mol%, the copolyarylates exhibited good melt processability. With regards to its solubility, thermal stability, mechanical properties and melt processability, PP30 may be considered as a promising candidate in the field of processable high‐performance engineering plastics. © 2019 Society of Chemical Industry

A new approach for the functionalisation of polysulfone with β-cyclodextrin

Functionalisation of polysulfone (PSU) with β-cyclodextrin (β.CD) is a potential vehicle for the design of drug delivery devices via complexation. In this approach, PSU film was first pre-activated by air plasma to facilitate a post-grafting reaction with methacrylic acid (MAA) and then amination by diamino-dipropylamine (DADPA). Finally, β.CD was anchored on to PSU-PMAA-DADPA surfaces via covalent bonding with amino groups. Creation of functional groups was confirmed by ATR-FTIR and functionalisation of PSU-PMAA-DADPA film with β.CD was verified by UV absorbance following immersion in phenolphthalein (PHP), which formed inclusion complexes with the attached β.CD. A reduction in absorbance of the PHP solution was observed, together with an increase in PHP exhaustion on to the PSU-PMAA-DADPA films as a result of functionalisation with β.CD. Increasing the amount of β.CD attached to the PSU-PMAA-DADPA films progressively increased PHP exhaustion until saturation was achieved.

BIODEGRADABILITY OF BIOPLASTIC IN NATURAL ENVIRONMENT

Biodegradation of the bioplastic composite based on cellulose from oil palm empty fruit bunches was investigated in this study. Microbes consortium from landfill soil collected from top soil were used as the inoculums for the biodegradation process. Biodegradation test of the bioplastic from oil palm empty fruit bunch samples compared with oxodegradation and conventional plastic samples were conducted in the glass jar. The biodegradation rate was evaluated from CO2 generated from the biodegradation process and absorbed by 0.1 N sodium hydroxide solutions. The generated CO2 was titrated with 0.1 N HCl and using phenolphthalein (PP) followed by methyl oranges indicator. The results showed that the highest CO2 production on landfill soil indicating the highest rate of biodegradation was found on bioplastic from oil palm empty fruit bunch followed by oxodegradable plastic and conventional plastic. The rate of biodegradation for bioplastic from oil palm empty fruit bunch, oxodegradable plastic and conventional plastic were 0.067mg CO2/day, 0.052 mg CO2/day and 0 mg CO2/day, respectively.

Dual pH/thermal-dependent coloring polymeric dye through Mannich reaction of chitosan: Synthesis and characterization

A novel polymeric dye was synthesized by one-pot Mannich reaction of chitosan (CS) and phenolphthalein (PHP). The grafting onto side chain of CS derivatives was confirmed by UV–vis, FT-IR, 1H NMR techniques. The degree of substitution (DS) calculated by 1H NMR and elemental analysis was revealed to increase with increasing mole ratio of formaldehyde and PHP. XRD analysis showed that the grafting through Mannich reaction was caused to amorphous structure in the derivatives. Covalent grafting of PHP onto CS made the grafted products showing pink color in basic conditions without leaching of dye and color fading after several weeks. Moreover, the derivatives dissolved in LiOH/urea systems could showed darker pink after heating. The results suggested that the novel CS derivatives with dual pH/thermal-dependent coloring property could potentially be prepared as pH/thermal-responsive biomaterial in a wide range of applications.

Effects of macromolecular topology on the encapsulation and release of phenolphthalein from hyperbranced glycerol modified β-cyclodextrin

In the study, CD-g-HPGs with various arm length and arm number were synthesized and characterized by 1H NMR, 13C NMR and Gel Permeation Chromatographic (GPC). Phenolphthalein (PP), as a small hydrophobic guest was readily encapsulated in the cavity of β-CDs or the hydrophobic aggregation domains stacked by cavities of β-CDs. CD-g-HPGs bearing longer arm length and denser arm number exhibited an increased loading capacity and exerted a profound influence on the release behavior, that is, longer arm accelerated the release, while a higher density of arm number slowed down the release owing to the synergy effect of aggregation and host-guest interaction between β-CD and PP. Via adjusting the host-guest interaction, CD-g-HPGs provided a potential to design efficient carriers or reasonable assemble systems.

Effect of calcination temperature on the photocatalytic activity of carbon‐doped titanium dioxide revealed by photoluminescence study

Carbon‐doped titania (C‐TiO2) nanoparticles were synthesized by the sol–gel method at different calcination temperatures (300–600°C) employing titanium tetraisopropoxide (TTIP) as the titanium source and polyoxyethylene sorbitan monooleate (Tween 80) as the carbon source. The physical properties of C‐TiO2 samples were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic activities were checked through the photodegradation of phenolphthalein (PHP) under ultraviolet irradiation. The UV spectrum showed that the carbon doping extends the absorption range of TiO2 to the visible region. However, the photocatalytic activity is affected by the electron–hole recombination phenomenon, as revealed by the photoluminescence (PL) study. According to the PL spectra, carbon doping reduces the edge‐to‐edge electron–hole recombination. Nevertheless, the number of defect sites is greatly influenced by the calcination temperature of C‐TiO2. C‐TiO2 that was calcined at 400°C showed the highest photodegradation percentage of PHP, which was mainly attributed to the synergic effect of the low direct edge‐to‐edge electron–hole recombination, high content of defect sites, and retention of active electrons on the surface hydroxyl group.

Szürkevizek detergens tartalmának meghatározására alkalmas analitikai módszerek fejlesztése

In our research we improved the technologies for the determinations of greywaters’ detergent content. We examined the quantity of anionic detergent (ANA) in synthetic greywater with Hyamine reagent using two-phased titrimetric method. We added to the synthetic greywater samples phenolphthalein indicator, acid mixed indicator and chloroform. After we shaked the mixture, and we got two separated phase. We titrated the mixture with cation active Hyamine reagent. The quantity of the chloroform and the quality of greywater samples (syntetic and real) were also changed in these experiment to determinate the actual ANA content. It was shown that the applied method is representative and reliable, too.

Clinical study of abdominal acupoint massage combined with sticking therapy in the treatment of constipation after thoracolumbar fracture

Objective To investigate the clinical effect of massage combined with abdominal acupoint sticking therapy in the treatment of constipation after thoracolumbar fractures. Methods 50 thoracolumbar fracture patients with constipation were selected as the research subjects.According to the computer random grouping, all patients were divided into two groups, 25 cases in each group.The control group received phenolphthalein tablets.The observation group underwent abdominal acupoint massage and sticking therapy treatment.The two groups were treated for a course of 7 days.The clinical curative effect, defecation feeling, stool, defecation frequency and number of vector gas were compared between the two groups. Results After treatment, the proportions of defecation and carefree, laborious and soft, dry in the observation group were 76.00%, 24.00%, 88.00%, 12.00%, respectively, compared with the control group, there were statistically significant differences (χ2=6.65, 6.35, all P<0.01). The total improvement rate after treatment in the observation group was 96.00%, which was significantly higher than 72.00% in the control group(χ2=5.36, P=0.02). After treatment for 48 hours and 72 hours, the frequency of defecation and the number of vector gas times in the observation group were higher than the control group(t=6.22, 22.37, 10.29, 8.97, all P<0.05). Conclusion Abdominal acupoint massage combined with sticking therapy in the treatment of constipation after thoracolumbar fractures has significant clinical effect. Key words: Constipation; Phenolphthalein tablets; Acupoint sticking therapy; Massage; Lumbar vertebrae

Identification of blood stains under different environmental conditions

Blood stain analysis is an important area in crime investigation; which might get affected due to many condition. In present study the blood stains were prepared on different fabrics and then placed in different environmental conditions (different temperatures and pH) and was analyzed by chemical reagent (phenolphthalein). We found that the adverse temperature conditions interferes in identification of blood stains and it should be taken into consideration while analysis.

Unraveling the binding of phenolphthalein with serum protein and releasing by β-cyclodextrin

The biomolecular interaction of a potential prototype drug phenolphthalein (PN) with the transport protein bovine serum albumin (BSA) has been investigated at physiological pH employing various spectroscopic techniques along with computational study. The effect of β-cyclodextrin (β-CD) on PN-bound protein has also been investigated. The interesting phenomenon of all findings is the spontaneous exothermic binding of PN with serum albumin through static quenching mechanism. The thermodynamic parameters (ΔS°, ΔH° & ΔG°) have been justified by the detailed understanding of the binding affinity of PN with protein. The binding displacement measurements and Auto Dock-based docking simulation unravels the probable binding location of PN within the hydrophilic sub-domain IB close to Sudlow site I of BSA where Trp-134 is housed. Although β-CD induces a marginal structural loss of protein, it have played dominant roles to stripping of denaturant from PN-BSA assembles. This study has undertaken to unravel the effect of drug binding of protein so as to rationalize the applicability of the drug molecule as a therapeutic agent and drug delivery.

Multifunctional Stimuli-Responsive Supramolecular Materials with Stretching, Coloring, and Self-Healing Properties Functionalized via Host–Guest Interactions

The visualization of changes in the stress and bonding state inside polymeric materials is an attractive function in materials science. In this study, phenolphthalein (PP) was selected to prepare stimuli-responsive coloring materials. PP becomes purple under basic conditions in aqueous solutions; however, PP becomes colorless under basic conditions when it forms a complex with β-cyclodextrin (βCD). To exploit this property of PP, we prepared a color-changing hydrogel (βCD-PP AAm hydrogel) based on acrylamide (AAm) as the main chain and βCD and PP moieties as the side chains. The βCD-PP AAm hydrogel exhibits a color change when heat or a competing molecule is applied at a pH less than 8. This color change was confirmed by ultraviolet–visible (UV–vis) spectroscopy, and the mechanical properties were determined via compression and tensile measurements. The βCD-PP AAm hydrogel also exhibits a rapid, reversible color change upon Joule heating produced by an electric current passing through the gel.

Possible Using of Tetra Bromo Phenol Phthalein Ethyl Ester as a Liquid Dosimeter

Possible Using of Tetra Bromo Phenol Phthalein Ethyl Ester as a Liquid Dosimeter