Phenol Red Research Articles

Use of Brushite as Adsorbent for the Removal of Anionic and Cationic Dyes Present in Aqueous Solutions

Currently, water pollution caused by dyes is a serious problem since they are toxic and carcinogenic to living beings. To reduce the presence of these contaminants, natural adsorbents have been considered as they are easy to obtain, inexpensive, and have high removal efficiency. In this work, the adsorption process using natural brushite (nDCPD) was studied for the removal of phenol red (PR), achieving a removal rate of 99.15% and an adsorption capacity of 82.24 mg/g, and gentian violet (GV), achieving a removal rate of 97.03% and an adsorption capacity of 74.22 mg/g. Equilibrium adsorption occurs for both dyes in multiple layers on the surface. The adsorption process is spontaneous for both dyes. The kinetics of the adsorption process involve using a single active site on the surface for PR adsorption, while for GV, two active sites on the surface are required. Analysis via FTIR, EDS, and XRD revealed various mechanisms that intervene in the adsorption process of both dyes on the surface of nDCPD, such as electrostatic forces, functional groups, physisorption, and ion exchange.

Mesoporous and thermally stable phenol red encapsulated Ag-SiO2 and zincite decorated Ag-SiO2 opto-chemical Sensor

Sol-gel-based silver-doped silicon dioxide (Ag-SiO2) and zincite-decorated silver-doped silicon dioxide (Z-Ag-SiO2) are synthesized at low temperatures (80 °C). The pH indicator dye phenol red (PR) is encapsulated in Ag-SiO2 (AS) and Z-Ag-SiO2 (ZAS) for pH assessment at dynamic pH 12. Thermally stable PR encapsulated AS nanocomposite and PR encapsulated ZAS nanocomposite revealed porous nanostructure with a crystallite size of approximately 0.85 nm and 1.21 nm. The PR/AS and PR/ZAS nanocomposites also feature a surface area of about 438 m2g−1 and 370 m2g−1, respectively. The PR/AS and PR/ZAS demonstrate a pKa of 10.9 and 10.2 at 560 nm, and a rapid color response of approximately 0.46 s and 0.25 s at pH 12.

Rapid detection of imipenem/relebactam susceptibility/resistance in Pseudomonas aeruginosa

ObjectivesImipenem-relebactam (IPR) has been reported to exhibit a good activity against non-metallo-ß-lactamase carbapenem-resistant Pseudomonas aeruginosa (CRPA), and the rapid detection of susceptibility/resistance to this new therapeutic alternative may be crucial. Therefore, the Rapid IPR Pseudomonas NP test was developed to quickly identify IPR susceptibility/resistance among multidrug-resistant P. aeruginosa. MethodsThe principle of the Rapid IPR Pseudomonas NP test is based on visually detecting glucose metabolization by observing (or not) a color change from yellow to red or orange of the red phenol pH indicator in the presence of imipenem at 2 mg/L and relebactam at 4 mg/L A total of 80 clinical Pseudomonas aeruginosa isolates were analyzed, among which 42 isolates were IPR resistant according to EUCAST guidelines (MICs, susceptible ≤2 mg/L, resistant >2 mg/L). Results obtained with the Rapid IPR Pseudomonas NP test were compared with the reference broth microdilution (BMD). ResultsThe sensitivity, specificity and accuracy of the test were found to be 100 %, 89.5 % and 95 %, respectively, using the BMD reference method as a comparator. Moreover, five out of the IPR-susceptible isolates (n = 38) exhibiting an MIC of IPR close to the breakpoint (MIC = 1 mg/L, n = 2; MIC = 2 mg/L, n = 3) yielded to a major error result, namely a positive result with the rapid IPR Pseudomonas NP test (resistance). By contrast, all IPR-resistant isolates (n = 42) were all correctly categorized. ConclusionsThe Rapid IPR Pseudomonas NP test is sensitive, specific, and easy to perform and interpret. Therefore, it is suitable for implementation in routine clinical laboratories.

Enhanced composite Co-MOF-derived sodium carboxymethyl cellulose visual films for real-time and in situ monitoring fresh-cut apple freshness

Natural biopolymers have extensively applications in intelligent food packaging due to their renewable nature, easy availability, environmental-friendly, low-cost and excellent processibility. Recently, the integration or embedding of nanocomposites on polymer substrates to improve the multi-faceted performance of packaging materials has attracted widespread attention. Herein, the irregular spherical Co-based metal-organic framework (Co-MOF) loaded with phenol red (PR) and bromothymol blue (BTB) were fabricated, resulting in absorbed nanocomposites Co-MOF/PR and Co-MOF/BTB. Afterward, the nanocomposites were integrated into a sodium carboxymethyl cellulose (CMC-Na) substrate to prepare a CO2-responsive packaging material (CMC-Na/PR/Co-MOF and CMC-Na/BTB/Co-MOF) for real-time and in-situ monitoring apple freshness. The synthesis of Co-MOF and the hydrogen-bonding interactions between MOF and pigments adsorption were confirmed. The advantages exhibited by the film with adding Co-MOF, including excellent hydrophobicity and water resistance, improved time-temperature stability and mechanical properties, were explored. Notably, the Co-MOF-based composite film exhibited enhanced UV–visible barrier, anti-migration performance of pigment, and thermal stability. Finally, a significant linear response (R2 = 0.9923 and 0.9781) between the total color difference values (ΔE) of Co-MOF-based film and hardness and total soluble solids (TSS) of fresh-cut Fuji apples at 4 °C was demonstrated, respectively. These findings indicate the significant potential of CMC-Na-based composite film containing multifunctional MOF nano-filler as a visual monitoring system, which will pave the way for fresh-cut fruit intelligent packaging.

Green synthesis of silver nanoparticles using Senna alexandrina leaf extracts and their antibacterial, larvicidal, nanotoxicity and photocatalytic activity

Biological synthesis of metal nanoparticles has been discovered in recent years, and they have been effectively manufactured and studied from diverse plant extracts. Recent research has shown that nanoparticles have extremely promising antibacterial, larvicidal and anticancer effects. The current study aimed to synthesize Senna alexandrina leaf extract-mediated silver nanoparticles (SA-AgNPs) as are reducing and capping agent. The produced SA-AgNPs were characterized by using UV–visible spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and Field emission scanning electron microscopy with energy dispersive spectroscopy (FESEM-EDS). The result showed synthesized SA-AgNPs were confirmed by UV–visible spectroscopy with 440 nm absorption. FT-IR analysis shows the presence of phosphine, primary amines, carboxylic acids, ether, and alkyl halides biomolecules in both plant extract and SA-AgNPs. XRD findings revealed the crystalline structures of produced SA-AgNPs. The spherical shape of SA-AgNPs with an average size of 20–35 nm was confirmed using FESEM. The SA-AgNPs show better antibacterial activity against E. coli (18.0 ± 0.25 mm), S. aureus (17.2 ± 0.36 mm), P. aeruginosa (16.8 ± 0.12 mm), and leaf extract of S. alexandrina showed minimal antibacterial activity. The SA-AgNPs show 100 % mortality for both Cx. quinquefasciatus and Ae. aegypti after 48 hrs. The brine shrimp lethal assay of the SA-AgNPs shows 100 % at 30 µg after 24 hrs of brine shrimp which indicated the presence of cytotoxicity this suggests that produced SA-AgNPs are slightly toxic. The photocatalytic activity was also tested using reactive orange 16 (RO16) and phenol red (PR) with the percentage of degradation being about 93.95 % and 92.91 % respectively. These results suggest that biosynthesized SA-AgNPs have promising properties that can be used as an effective biomedical and environmental protectant.

Biogenic Iron Oxide Nanoparticles Based on Algal Biofilm Formed in the Wastewater Treatment Plant and Their Dye Removal Performance

In the field of environmental pollution removal, bioremediation plays a crucial role in removing or converting toxic substances from the environment. Bacteria, yeasts, molds, algae, and plants are widely used in bioremediation events. Recently, green-synthesized nanoparticles have also been employed in bioremediation applications. In this study, iron oxide nanoparticles (FeONPs) were synthesized from algal biofilms that are naturally formed in the settling ponds of the Gümüşhane Municipality Wastewater Treatment Plant. These biological nanoparticles were utilized to investigate their adsorption efficiency for water-polluting dyes such as methylene blue (MB), malachite green (MG), and phenol red (PR). The synthesized FeONPs were characterized using Fourier transform infrared spectroscopy (FTIR) scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). To test their efficacy, MB, MG, and PR dye solutions were treated with 5.0, 10.0, and 20 g/L FeONP concentrations. The remaining dye concentrations were quantified with a UV-VIS spectrophotometer after filtration. The results showed that FeONPs obtained from algal biofilms effectively removed MB, MG, and PR, with the highest efficiency observed for PR.

The phenol red compound: A potential artifact in pharmacological induction of ferroptosis

Phenol red (PR) is a commonly used compound in culture media as a pH indicator. However, it is unknown whether this compound can interfere with the pharmacological induction of ferroptosis. Here, using high-content live-cell imaging death analysis, we determined that the presence of PR in the culture medium preconditioned normal and tumor cells to ferroptosis induced by system xc− inhibition mediated by imidazole ketone erastin (IKE) or GPX4 blockade in response to RSL-3, but had no significant effects against treatment with the endoperoxide FINO2. Mechanistically, we revealed that PR decreases the levels of the antiferroptotic genes Slc7a11, Slc3a2, and Gpx4, while promoting the overexpression de Acls4, a key inducer of ferroptosis. Additionally, through superresolution analysis, we determined that the presence of PR mislocalizes the system xc− from the plasma membrane. Thus, our results show that the presence of PR in the culture medium can be a problematic artifact for the accurate interpretation of cell sensitivity to IKE or RSL-3-mediated ferroptosis induction.

Dye degradation activity of biogenically synthesized Cu/Fe/Ag trimetallic nanoparticles

Abstract Over the past few decades, nanotechnology has gained momentum because of its potential to create a safer and healthier living environment using eco-friendly approaches. This study describes a safer, more dependable, and ecologically friendly technique of biologically synthesizing Cu/Fe/Ag trimetallic nanoparticles (NPs) using an aqueous leaf extract of Catharanthus roseus as the reducing and stabilizing agent. The synthesized trimetallic NPs were characterized by scanning electron microscope, Fourier transform infrared, dynamic light scattering, and ultraviolet–visible analysis and were evaluated for their potential applications, which included antioxidant properties and catalytic dye degradation. The result suggests that the antioxidant properties of Cu/Fe/Ag NPs are more significant than those of ascorbic acid, a known antioxidant, at lower doses (10 µg·ml−1) while a higher dose of 1,000 µg·ml−1 gives a 69.81% scavenging activity. The impact of Cu/Fe/Ag trimetallic NPs on the catalytic degradation of hazardous dyes such as phenol red (PR) and eosin yellow (EY) was also studied in this work. For PR and EY, the corresponding percentages of degradation were 76% and 48.6%, respectively.

Structural characterization of electrospun ZrO2-based catalytic nanofibers modified with B2O3 and their performance in bromination reaction of phenol red

Structural characterization of electrospun ZrO2-based catalytic nanofibers modified with B2O3 and their performance in bromination reaction of phenol red

Electro-oxidation of synthetic lignin with different mediators for the laccase mediator system (3-hydroxyanthranilic acid, 4-hydroxybenzoic acid, phenol red)

Three mediators for the laccase mediator system, 3-hydroxyanthranilic acid (3-HAA), 4-hydroxybenzoic acid (HBA), and phenol red (PR) were investigated as mediators in an electrolytic mediator system (EMS) for the degradation of guaiacyl synthetic lignin (G-DHP). All the electron-oxidations of G-DHP with 3-HAA, HBA and PR in the absence of 2,6-lutidine proceeded to give the electrolysis residues in moderate yields. The significant β-β and β-5 linkage loss was found in all the electrolysis residues, especially the residue in the electro-oxidation with PR was significant. The addition of 2,6-lutidine as a base increased the yields of the electrolysis residues and influenced the relative ratio of β-O-4, β-5 and β-β linkages to some extent, that is, increase of β-O-4 linkage loss and decrease of β-β linkages loss (in the electro-oxidation with 3-HAA), increase of β-O-4 linkage loss (in that with 3-HBA), increase of β-5 linkages loss (in that with PR at 0.35 V) and decrease of β-O-4 and β-β linkages loss (in that with PR at 0.70 V). Thus, the base such as 2,6-lutidine was also one of the critical factors for reaction efficiency and reaction selectivity in the EMS. Consequently,3-HAA, HBA, and PR could be used as mediators in EMS for lignin degradation, especially 3-HAA is the most preferable because of the low applied potential.

MultiRapid ATB NP test for detecting concomitant susceptibility and resistance of last-resort novel antibiotics available to treat multidrug-resistant Enterobacterales infections

BackgroundRecently developed therapeutics against Gram-negative bacteria include the β-lactam-β-lactamase inhibitor combinations ceftazidime–avibactam (CZA), meropenem–vaborbactam (MEV), and imipenem–relebatam (IPR), and the siderophore cephalosporin cefiderocol (FDC). The aim of this study was to develop a test for rapid identification of susceptibility/resistance to CZA, MEV, IPR, and FDC for Enterobacterales in a single test for rapid clinical decision making. MethodsThe MultiRapid ATB NP test is based on the detection of glucose metabolism occurring after bacterial growth in the presence of defined concentrations of CZA, MEV, IPR, and FDC, followed by visual detection of colour change of the pH indicator red phenol (red to yellow) generated by the acidification of the medium upon bacterial growth. This test is performed in 96-well microplates. The MultiRapid ATB NP test was evaluated using 78 Enterobacterales isolates and compared to the reference method broth microdilution. ResultsThe MultiRapid ATB NP test displayed 97.0% (confidence interval [CI] 92.6–98.8) sensitivity, 97.7% (CI 94.3–99.1) specificity, and 97.4% (CI 95.0–98.7) accuracy. The results were obtained after 3 h of incubation at 35 °C ± 2 °C, representing at least a 15-h gain-of-time compared with currently used antimicrobial susceptibility testing methods. ConclusionThe MultiRapid ATB NP test provided accurate results for the concomitant detection of susceptibility/resistance to CZA, MEV, IPR, and FDC in Enterobacterales, independent of the resistance mechanism. This test may be suitable for implementation in any microbiology routine laboratory.

Tailoring the optical properties of dye–polymer composite films based on polyvinyl alcohol doped with phenol red toward flexible optoelectronic applications

The composite films of polyvinyl alcohol (PVA) incorporating varying concentrations of phenol red (PR) dye were fabricated using the solution casting method. Structural characteristics of the prepared films were explored through XRD and FTIR spectroscopy analyses. The inclusion of PR dye within the PVA matrix induced cross-linking, enhancing the amorphous nature of the doped PVA samples, as evidenced by XRD patterns. In the presence of PR dopants, the FTIR peaks for PVA exhibited altered intensities and increased width, indicating physical interactions between the functional groups of PVA and PR dopants. The impact of PR additives on the optical properties of PVA was investigated across the spectral range of 190–2500 nm. The PVA/phenol red composite demonstrated enhanced UV blocking in the 190–400 nm wavelength range, rendering it suitable for applications such as UV notch filters, including laser blocking filters. The indirect and direct optical band-gaps of PVA polymer films were reduced from 5.20 eV and 5.78 eV to 4.30 eV and 5.28 eV, respectively, with an increase in the PR filling ratio from 0 wt% to 1.8 wt%. The dispersion region of the refractive index was analyzed using the single oscillator model (Wemple-DiDomenico). Calculation and discussion of values such as dispersion and oscillation energies (Ed and Eo), permittivity at infinite frequency (ε ∞), and lattice contribution to the dielectric function (ε L) of PVA/PR composite films were conducted. These advancements position PVA/PR composite films for potential applications in flexible optoelectronic devices, including light-emitting diodes and photodetectors.

A smartphone-assisted sensing hydrogels based on UCNPs@SiO2-phenol red nanoprobes for detecting the pH of aquatic products

For some aquatic products, pH has been considered a useful index to reflect the changes in materials during the loss of freshness. Based on the inner filter effect (IFE) between deprotonated phenol red (PR) and upconversion nanoparticles (UCNPs), UCNPs coated with PR-doped SiO2 shell were embedded in agarose hydrogel to develop a smartphone-assisted method for pH sensing. With the enhancement of pH response using a phase transfer agent (i.e., tetra butyl ammonium hydroxide, TBAH), the proposed senor realized the colorimetric and fluorescence detection of pH in the range of pH 6.6–8 and pH 6–8, respectively. The sensor also showed satisfied reversibility when switched between pH 6 and 8 for at least 5 cycles. Moreover, this sensor displayed great sensitivity, stability, and portability in analyzing actual fish, shrimp, and shellfish samples, providing a new sight for evaluating the freshness of aquatic products.

CoFe2O4/PANI/MWCNTs ternary hybrid composites. Synthesis, characterization, the effect of MWCNTs ratio and dye removal capability.

We have synthesized cobalt ferrite (CoFe2O4) using the sucrose auto-combustion method and subsequently employed the in situ polymerization technique to fabricate ternary composites comprising CoFe2O4, polyaniline (PANI), and multi-walled carbon nanotubes (MWCNTs). In this novel investigation, we explored the influence of varying MWCNTs ratios on these composites' structural, magnetic, thermal, and electrical properties. The crystal structures of the synthesized composites were analyzed using X-ray diffraction (XRD), while Fourier transform infrared (FT-IR) spectroscopy revealed changes in bonding patterns, including the disappearance of ferrite bonds and the emergence of new ones. Transmission electron microscopy (TEM) images illustrated a complete coating of PANI on both MWCNTs and CoFe2O4 particles, resulting in a substantial reduction in magnetization compared to pure CoFe2O4 ferrite due to PANI's nonmagnetic nature. Vibrating sample magnetometer (VSM) measurements confirmed this reduction, indicating a decrease to 7.3 emu.g-1. Thermal analysis demonstrated an enhancement in thermal stability with increasing MWCNTs content, as evidenced by an increase in the temperature equivalent for half decomposition (T50) from 486 to 522°C for composites with 40% MWCNTs. Moreover, the electrical conductivity showed a corresponding rise with MWCNTs content, increasing from 3.1 × 10-3 Ω-1.cm-1 to 2.2 × 10-2 Ω-1.cm-1, possibly indicating charge transfer from PANI to MWCNTs. To assess practical applications, we investigated the ability of the composite with 40% MWCNTs to remove phenol red (PR) dye from aqueous solutions. Through a systematic study of adsorption parameters and kinetics, we determined optimal conditions for effective dye removal and elucidated the underlying adsorption mechanism. Our results demonstrated the composite's efficiency in dye removal, with a 6.4mg·g-1 capacity for PR dye, highlighting its potential for environmental remediation efforts.

Phenol Red Solution (1%, w/v)

Phenol Red Solution (1%, w/v)

The Effect of Postoperative Ileus on the Gastrointestinal Motility of Rats

Postoperative ileus (POI) is defined as a prolonged absence of bowel function which can occur after an abdominal surgical procedure. Due to the complications caused by POI, hospital stays and related costs have been shown to increase. The purpose of this study was to determine the effects of POI on the gastrointestinal (GI) motility of rats. Sprague-Dawley rats were given a meal with phenol red and POI was induced via abdominal surgery. The experimental and the naive control group had stomachs and small intestines (SI) isolated and each SI was divided into 7 equal-length pieces. Each created a homogenous mixture and the amount of phenol red was determined. Positive differences for SI 2 to 8 indicated delayed intestinal motility in the experimental group. The stomachs in the experimental group had a significantly larger (p<0.05) amount of meal inside (0.362 ± 0.031 absorbance) compared to the stomachs of the control rats (0.176 ± 0.032 absorbance), suggesting a slower rate of food passage in the experimental group. These findings suggest that surgically induced POI causes a decrease in GI motility in rats. Future studies could focus on the effects of neostigmine on the decrease of POI in rats, for the purpose of eliminating discomfort during survival surgeries in rat models.

High-performance e-beam-deposited (Sn2Sb2S5)GO:FTO supercapacitor electrode and photocatalytic thinfilm for contaminants removal

The present work outlines the synthesis of e-beam deposited (Sn2Sb2S5)GO:FTO thin film. The surface and physicochemical characterization of the thinfilm was done through X-ray diffraction (XRD), X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray and UV-visible spectrophotometry. An orthorhombic phased Sn2Sb2S5-GO was confirmed by XRD with crystallite size of 16.9 nm. SEM morphology revealed homogenous distribution of grains and sheet-like structure of graphene oxide (GO) and a direct band gap of 2.9 eV. Moreover, electrical investigation presented (Sn2Sb2S5)GO:FTO as an excellent electrode material with 303 F g−1 specific capacitance. The photocatalytic degradation rates by the thinfilm for methyl red dye, pesticide and phenol were 70%, 94% and 54%. The dynamic properties of the investigated film present it as a propitious material for opto-electrical and remediation devices.

Rapid Detection of Ceftazidime/Avibactam Susceptibility/Resistance in Enterobacterales by Rapid CAZ/AVI NP Test.

We developed a novel culture-based test, the Rapid CAZ/AVI NP test, for rapid identification of ceftazidime/avibactam susceptibility/resistance in Enterobacterales. This test is based on glucose metabolization upon bacterial growth in the presence of a defined concentration of ceftazidime/avibactam (128/53 μg/mL). Bacterial growth is visually detectable by a red to yellow color change of red phenol, a pH indicator. A total of 101 well characterized enterobacterial isolates were used to evaluate the test performance. This test showed positive percent agreement of 100% and negative percent agreement of 98.5% with overall percent agreement of 99%, by comparison with the MIC gradient strip test (Etest) taken as the reference standard method. The Rapid CAZ/AVI NP test had only 1.5% major errors and 0% extremely major errors. This test is rapid (result within 2 hours 45 minutes), reliable, affordable, easily interpretable, and easy to implement in clinical microbiology laboratories without requiring any specific equipment.

Bromoperoxidase mimicry based on Bi2O2.33 nanosheets for aptasensing

To pursue new nanozyme mimetics with extended applications is appealing. Herein, Bi2O2.33 nanosheets were revealed as an efficient bromoperoxidase- and iodoperoxidase- mimetics with good catalytic capabilities for the bromination of phenol red (PR) and the iodination of thymol blue (TB) in the presence of H2O2, accompanied by the development of a ratiometric colorimetric signal. Exampled by the aptasensing of aflatoxin B1 (AFB1) as a model, a label-free, ultrasensitive, and selective ratiometric colorimetric sensing platform was constructed, achieving a low detection limit of 0.33 ng/mL. This work features a novel bromoperoxidase- and iodoperoxidase mimetic based on Bi2O2.33 nanosheets, which may arouse more interest in the exploration of haloperoxidase nanozymes with extended biosensing applications.

Smart Packaging for Chicken Meat Quality: Absorbent Food Pad and Whatman Paper Applications

Quality and shelf-life extension are major concerns in the development of meat packaging systems. The purpose of this study was to determine the effectiveness of absorbent food pads combined with intelligent packaging as well as to determine the correlation between active packaging and smart indicator labels. The active packaging applied absorbent food pads as carriers of active ingredients from basil and lemongrass, which are expected to extend the shelf life of chicken meat and maintain its quality. Meanwhile, intelligent packaging employs Whatman paper treated with Phenol Red (PR), providing real-time information on the quality of chicken meat. Various chicken meat spoilage test parameters such as thiobarbituric acid (TBA), total volatile base nitrogen (TVBN), total bacteria of total plate Count (TPC), and pH were tested at chiller temperature (4oC) every 3 × 24 hours. The results of this study indicated that an absorbent food pad with lemongrass essential oil can extend the shelf life of chicken meat by 3 days while, the intelligent indication label’s color profile changed from yellow at the beginning of application to red during chicken spoilage. Therefore, smart packaging from a combination of an absorbent food pad as active packaging and phenol red indicator label as intelligent packaging can potentially extend the shelf life of chicken and monitor the condition of chicken meat during storage.