Erythrosin B Research Articles

Exploring the AC conductivity and dielectric properties of PVA films doped with Erythrosin B

Erythrosin B (EB) doped in PVA film was processed utilizing the casting procedure, and the structure was investigated via the Fourier Transformation infrared technique (FTIR). FTIR analysis presented a strong formation of intermolecular hydrogen bonds among PVA and EB hydroxyl groups (OH). Characteristic temperature and frequency variation of dielectric behavior and AC electrical conductivity for films of PVA doped with Erythrosin B were analyzed at (293–383 K) temperature and (102–106 Hz) frequency. The AC conductivity dependency indicates that the predominant conduction mechanism in PVA doped with Erythrosin B films follows the correlated barrier hopping (CBH) model. The charge carriers’ hopping involving localized states causes a relaxation process. Estimates were made for the AC conductivity activation energy and the conductivity relaxation energy. Frequency and temperature affect the dielectric constant (ε′) and the dielectric loss (ε″). The complex impedance spectrum (Z′ versus Z″) showed single semicircular arcs with a decreased radius with increasing temperature. The relaxation peaks in the electric modulus representation are clearly defined, and the relaxation period has been calculated.

Spectroscopic characterization of the interactions between poly(2-(trimethylamino)ethyl methacrylate) chloride and the xanthene dyes, 2′, 7′-difluorofluorescein and 2, 4, 5, 7-tetraiodofluorescein

Intermolecular interactions in buffered aqueous solution between the polycation, poly(2-(trimethylamino)ethyl methacrylate) chloride (pTMAEMC) and two anionic xanthene dyes, 2′, 7′-difluorofluorescein (Oregon Green 488) and 2, 4, 5, 7-tetraiodofluorescein (Erythrosin B), are characterized using multiple optical spectroscopic methods. Visible absorption spectroscopy indicates the formation of ground-state pTMAEMC-dye complexes. Benesi-Hildebrand binding isotherm analysis of visible absorption spectra for pTMAEMC-dye mixtures quantifies the strength of binding interactions producing the complexes. For both Oregon Green 488 (OG) and Erythrosin B (EB) in mixtures with pTMAEMC, the concentration of the solution’s sodium acetate buffer at a fixed pH alters the binding constants, Kb, suggesting that ionic strength plays a key role in determining the binding affinity of pTMAEMC for the dyes. Comparison of Kb, for the dyes indicates stronger binding of EB under all solution conditions. Steady-state fluorescence emission spectroscopy, fluorescence quenching, excited-state fluorescence lifetime measurements and fluorescence correlation spectroscopy provide complementary data for the interactions between pTMAEMC and the dyes. Mixtures of pTMAEMC with the dyes produce fluorescence enhancements and fluorescence quenching which exhibit a dependence on the buffer concentration used in the mixture. Excited-state lifetime analysis indicates that OG interacts with pTMAEMC through ground-state interactions while EB exhibits both ground-state and excited-state interactions with pTMAEMC. The spectroscopic measurements suggest that a polyelectrolyte effect for pTMAEMC due to ionic strength variation produced by the buffer concentration affects the dye binding profile of the polycation. This conclusion is supported by fluorescence correlation spectroscopy (FCS) analyses of the hydrodynamic diameter changes in pTMAEMC-OG binding in low buffer concentration (low ionic strength) solution. FCS analyses of pTMAEMC-OG mixtures also reveal diversity in the complexes formed in low ionic strength solution suggesting that other xanthene dyes will exhibit similar binding behaviors in mixtures with pTMAEMC as a function of solution ionic strength.

Design and Architecture of P-O Co-Doped Porous g-C3N4 by Supramolecular Self-Assembly for Enhanced Hydrogen Evolution

A novel phosphorus and oxygen co-doped graphitic carbon nitride (sheetP-O-CNSSA) photocatalyst was successfully synthesized and applied for H2 evolution under visible light. In the synthesis process of sheetP-O-CNSSA, the supramolecular complex was developed by the self-assembly and copolymerization reaction among melamine, cyanuric acid (CA) and trithiocyanuric acid (TCA) to act as g-C3N4 precursors, while (NH4)2HPO4 was applied as P and O precursors for element doping. The chemical structures, morphologies, and optical properties of the sheetP-O-CNSSA were characterized by a series of measurements, i.e., XRD, FT-IR, SEM, TEM, UV-vis DRS, and PL. The results suggested that the introduction of P and O elements could enhance the separation and migration efficiency of photogenerated electrons and holes in the energy band of g-C3N4. The photocatalytic tests over Erythrosin B (EB) sensitized sheetP-O-CNSSA indicated that the hydrogen evolution was greatly enhanced compared with other catalysts and non-sensitized sheetP-O-CNSSA under visible light irradiation. Finally, a possible dye-sensitized photocatalysis mechanism was also proposed on the basis of the as-obtained results.

Erythrosin B as a New Photoswitchable Spin Label for Light-Induced Pulsed EPR Dipolar Spectroscopy.

We present a new photoswitchable spin label for light-induced pulsed electron paramagnetic resonance dipolar spectroscopy (LiPDS), the photoexcited triplet state of erythrosin B (EB), which is ideal for biological applications. With this label, we perform an in-depth study of the orientational effects in dipolar traces acquired using the refocused laser-induced magnetic dipole technique to obtain information on the distance and relative orientation between the EB and nitroxide labels in a rigid model peptide, in good agreement with density functional theory predictions. Additionally, we show that these orientational effects can be averaged to enable an orientation-independent analysis to determine the distance distribution. Furthermore, we demonstrate the feasibility of these experiments above liquid nitrogen temperatures, removing the need for expensive liquid helium or cryogen-free cryostats. The variety of choices in photoswitchable spin labels and the affordability of the experiments are critical for LiPDS to become a widespread methodology in structural biology.

Preparation and characterization of mixed matrix membranes based on PVDF blend and hydrophilic molecularly imprinted MIL-101 (Cr) as filler for efficient selective removal of dye

In the present study, a novel membranes were developed from tea filter bag as a base substrate which was subsequently coated by a casting solution containing polyvinylidene fluoride (PVDF) blending and addition of MIL-101 (Cr) metal-organic framework (MOF)- molecularly imprinted resorcinolformaldehydemelamine (MIRFM) as filler was prepared by phase inversion technique (PVDF/MIRFM). The MIRFM contains selective functional groups was used as filler in the adsorptive membrane. The as-prepared filler and mixed matrix membranes (MMMs) were characterized by FE-SEM, XRD, FTIR, BET and water contact angle (WCA). The filtration of Erythrosin B (EB) on the PVDF/MIRFM membranes were studied through investigating the parameters such as the mass of PVDF, filler and volume of Triton x-405 in a cross-module filtration setup. Casting solution containing of MIRFM demonstrated good wettability, high water flux, porosity (87.7%), flux recovery ratio (74.1%) and EB removal efficiency (91.5%). Results indicated that appropriate of MIRFM in membranes could be an effective and selective way for EB removal.

Protein discrimination using erythrosin B-based GUMBOS in combination with UV-Vis spectroscopy and chemometrics.

GUMBOS (Group of Uniform Materials Based on Organic Salts) have recently emerged as interesting materials for protein analysis due to their unique features and high tunability. In this regard, four novel erythrosin B (EB)-based GUMBOS were synthesized and their potential to discriminate among proteins with distinct properties (e.g., size, charge, and hydrophobicity) was assessed. These solid-phase materials were prepared using a single-step metathesis reaction between EB and various phosphonium and ammonium cations, namely tetrabutylphosphonium (P4444+), tributylhexadecylphosphonium (P44416+), tetrabutylammonium (N4444+), and benzyldimethylhexadecylammonium (BDHA+). Subsequently, the effect of pH (3.0, 4.5, and 6.0) and reaction time (5, 10, and 15min) on the discriminatory power of synthesized GUMBOS was evaluated. Absorption spectra resulting from the interaction between EB-based GUMBOS and proteins were analyzed using partial least squares discriminant analysis (PLSDA). Unlike time, the pH value was determined to have influence over GUMBOS discrimination potential. Correct protein assignments varied from 86.5% to 100.0%, and the best discriminatory results were observed for [P4444]2[EB] and [N4444]2[EB] at pH 6.0. Additionally, these two GUMBOS allowed discrimination of protein mixtures containing different ratios of albumin and myoglobin, which appeared as individualized clusters in the PLSDA scores plots. Overall, this study showcases EB-based GUMBOS as simple synthetic targets to provide a label-free, cost-effective, rapid, and successful approach for discrimination of single proteins and their mixtures.

Facile fabrication of leaf coral-like structured Cu-Al LDH/PVDF composite adsorptive membrane with enhanced adsorption performance

In the present study, the novel leaf coral-like structured composite membrane is synthesized from array growth of copper aluminum layered double hydroxide (Cu-Al LDH) onto the polyvinylidene fluoride (PVDF) membrane surface through simple hydrothermal method. The as-prepared Cu-Al LDH/PVDF composite was characterized by FE-SEM, EDS element mapping, XRD, FTIR, AFM, BET and water contact angle (WCA). The dye adsorption of as-synthesized composite was studied for removal Erythrosin B (EB) from aqueous solution. The obtained Cu-Al LDH/PVDF composite membrane exhibits higher hydrophilicity than PVDF membrane. The pseudo-second-order model properly described the adsorption kinetics of the obtained Cu-Al LDH/PVDF composite for EB. Adsorption isotherms for EB by the as-prepared composite were found to be satisfactorily fitted by the Langmuir model. The maximum adsorption capacity of the obtained Cu-Al LDH/PVDF composite was 17.36 mg g−1. The coexisting salts decreased the removal efficiency of EB on Cu-Al LDH/PVDF composite.

Facile One-Step Preparation and Efficient Photocatalytic Hydrogen Production of Composite MoS2/g-C3N4 Sensitized by Erythrosin B

MoS2/g-C3N4 (g-C3N4 [Formula: see text] graphitic carbon nitride) composite is considered as a promising photocatalyst for hydrogen production, while the preparation method still needs to be improved. Herein for the first time, nanosized MoS3 and melamine were used as starting materials and a facile one-pot calcination method was successfully applied for the synthesis of MoS2/g-C3N4. The physical and photophysical properties of the as-prepared MoS2/g-C3N4 were characterized by XRD, IR, SEM, TEM and XPS techniques. Sensitized by Erythrosin B (EB), the photocatalytic hydrogen production performance of MoS2/g-C3N4 was investigated and the amount of MoS2 was optimized. An excellent H2 production activity of 1091.2[Formula: see text][Formula: see text] was achieved for 43% MoS2/g-C3N4, which is about 330 times that of pure g-C3N4 (3.3[Formula: see text][Formula: see text]. In addition, its performance was compared with those of three other MoS2/g-C3N4 samples prepared by conventional methods and a possible mechanism of H2 production was proposed based on the photoluminescence and photoelectrochemical results.

Anionic Surfactant Sensing by Optical Properties of Erythrosin B

The nonlinear optical properties, absorbance and fluorescence spectra of Erythrosin B (ErB) aqueous solution in different CTAB concentration was studied. Z-scan technique under laser light excitation at 532 nm, was used for study reverse saturable absorption (RSA) of ErB. it was observed that the RSA of solution depend on CTAB concentration. A enhancing of absorbance and quenching of fluorescence is observed with increase of CTAB concentration in solution and the RSA can reduce the fluorescence intensity. It was proposed that the micelle can reduce the dye aggregation is solutions and it can affect on linear and nonlinear optical properties of ErB.

Titanate nanotube confined merger of organic photocatalysis and TEMPO catalysis for highly selective aerobic oxidation of sulfides

Here, it is discovered that titanate (H2Ti3O7) nanotubes can confine the merger of erythrosin B (ErB) photocatalysis and TEMPO catalysis for highly selective aerobic oxidation of sulfides under irradiation of green light-emitting diodes (LEDs).

Erythrosin B: a versatile colorimetric and fluorescent vital dye for bacteria.

Rapidly assaying cell viability for diverse bacteria species is not always straightforward. In eukaryotes, cell viability is often determined using colorimetric dyes; however, such dyes have not been identified for bacteria. We screened different dyes and found that erythrosin B (EB), a visibly red dye with fluorescent properties, functions as a vital dye for many Gram-positive and -negative bacteria. EB worked at a similar concentration for all bacteria studied and incubations were as short as 5min. Given EB's spectral properties, diverse experimental approaches are possible to rapidly visualize and/or quantitate dead bacterial cells in a population. As the first broadly applicable colorimetric viability dye for bacteria, EB provides a cost-effective alternative for researchers in academia and industry.

UiO-66 MOFs as electron transport channel to short circuit dye photosensitizer and NiS2 co-catalyst for increased hydrogen generation

Abstract We report an Erythrosin B (ErB) dye/UiO-66/NiS2 system to achieve the increased photocatalytic H2 generation, in which UiO-66 serves as the electron channel to transport the electrons from photoexcited ErB dye to NiS2 co-catalyst. The π-π interaction ensures an effective adsorption of ErB dye upon UiO-66 and the functionalized organic linkers guarantee the growth of NiS2. The UiO-66/NiS2 composite with optimal content of NiS2 (5.0 wt%) offers an active H2 generation rate of 18.4 μmol h−1, nearly 2 times higher than that by using NiS2 and ErB (9.8 μmol h−1). The present study manifests the advantage of metal-organic frameworks (MOFs) as the electron transfer channel to boost the H2 generation of conventional systems containing photosensitizer and H2 generation co-catalyst.

Dye-sensitized black phosphorus nanosheets decorated with Pt cocatalyst for highly efficient photocatalytic hydrogen evolution under visible light

Although black phosphorous (BP) and its derived materials have shown great potential for application in photocatalytic H2 evolution reaction (HER), their HER activity and stability still remains unsatisfied mainly due to the insufficient charge separation, the lack of surface active sites, and the defect-riched nature of BP. Herein, we report that BP nanosheets decorated with in situ grown Pt (BP NSs/Pt) could act as a highly efficient catalyst for photocatalytic H2 evolution in an Erythrosin B (ErB)-sensitized system under visible light irradiation (≥450 nm) in the presence of triethanolamine (TEOA) as sacrificial electron donor. It is found that BP NSs can provide large surface area for the confined growth of Pt nanoparticles with a high dispersion and a reduced size but also stabilize the loaded Pt nanoparticles by covalent bonds at the BP NSs/Pt interfaces. Moreover, BP NSs offer a fast electron transfer pathway to facilitate the photocatalytic HER over in situ grown Pt catalyst. As a result, BP NSs/Pt catalyst exhibits ∼6 times higher H2 evolution activity than free Pt nanoparticles and an apparent quantum yield (AQY) of 0.57% at 500 nm irradiation in ErB-TEOA system. This work indicates the potential of BP NSs as an effective 2D matrix to construct numerous high performance photocatalysts and photocatalytic systems.

Modulating hydrophobicity of composite polyamide membranes to enhance the organic solvent nanofiltration

A kind of thin film composite polyamide nanofiltration (NF) membrane was synthesized via the interfacial polymerization between a new diamine monomer of 4,4′-diaminodiphenylmethane and trimesoyl chloride on the surface of cross-linked polyetherimide, and evaluated in some organic solvents including ACN, MeOH, EtOH, THF, etc. The optimal organic solvent NF membrane was selected to prepare respectively the hydrophilic membrane (Phi-NF) via grafting of Tris and the hydrophobic membrane (Pho-NF) via grafting of 2,2,2-trifluoroethylamine, combining with the characterization of ATR-FTIR, XPS, SEM, 13C NMR, AFM, etc. The permeance values of Phi-NF and Pho-NF membranes change greatly with organic solvents. Pho-NF-2 possesses the highest permeance of 66.4 L m−2 h−1 MPa−1 in THF with the erythrosin B (EB) rejection of 99.5%. Through analyzing the physiochemical properties of the organic solvents and calculating the surface energy, the correlations are deduced for the synthesized membranes, illustrating that the permeances of organic solvents are roughly proportional to the specific solvent properties for Phi-NF-2 and Pho-NF-2. The results suggest one promising method to enhance the separation performance of organic solvent NF membranes.

New promising polymer for organic solvent nanofiltration: Oxidized poly (arylene sulfide sulfone)

Polymeric membranes have attracted much interest in recent years for use in organic solvent nanofiltration. This article reports the development of a novel solvent resistant oxidized poly (arylene sulfide sulfone) (PASS) membrane and proposes a new strategy to enhance the solvent resistance of this PASS membrane via improving the rigidity, intermolecular interaction and packing density of polymer chains by a simple oxidation process. The PASS membranes were firstly fabricated by phase inversion, and then a facile green oxidation process was carried out to improve their solvent resistance. The oxidized PASS (O-PASS) membrane was found to exhibit an excellent stability in aggressive solvents, such as DMF and NMP, and endure 98% H2SO4 without sacrificing its filtration performance. In organic solvent nanofiltration (OSN), the O-PASS membranes exhibited a high rejection of dyes such as rose Bengal (RB), erythrosin B (EB), reactive orange 16 (RB16) and Sudan black B (SBB), and a stable filtration performance for 30h in DMF. Compared to other reported OSN membranes, this membrane showed an exceptionally high solvent permeation. This extraordinary OSN filtration performance, easy fabrication process and the strong solvent resistance, make PASS a very promising polymer in the field of OSN.

Facile wet-chemical synthesis and efficient photocatalytic hydrogen production of amorphous MoS3 sensitized by Erythrosin B

Herein, an amorphous MoS3 sample suitable for cost-effective and large-scale photocatalytic hydrogen production was prepared via a very simple and practicable wet chemistry method. Using Erythrosin B (EB) as sensitizer, the obtained MoS3 exhibits much higher hydrogen evolution performance (1190.0μmolh−1) than the most extensively studied crystalline MoS2 (180.9μmolh−1) prepared by widely-used hydrothermal method. In addition, the stabilities of MoS3 and EB-MoS3 system were evaluated. Series of analyses indicated that similar to previous reports, gradual composition change from MoS3 to MoS2 happens during the H2 evolution process and the amorphous MoS2 formed is the actual active species for H2 evolution. However, further extensive studies showed that except for photodegradation of EB, activity decrease during long-term or recycling test should mainly originate from the occupation of partial active sites on catalyst surface by some species existing in the reaction mixture, but not from the transformation from amorphous MoS2 to crystalline one. We think that this amorphous MoS3 is a promising material for photocatalytic hydrogen production.

Photodynamic Efficiency of Xanthene Dyes and Their Phototoxicity against a Carcinoma Cell Line: A Computational and Experimental Study

The aim of this study is to assess the insights of molecular properties of the xanthene dyes [fluorescein (FL), Rose Bengal (RB), erythrosin B (EB), and eosin Y (EY)] to correlate systematically their photodynamic efficiency as well as their phototoxicity against a carcinoma cell line. The phototoxicity was evaluated by comparing the values of the medium inhibitory concentration (IC50) upon HEp-2 cells with the xanthene corresponding photodynamic activity using the uric acid as a chemical dosimeter and their octanol-water partition coefficient (log⁡P).RBwas the more cytotoxic dye against HEp-2 cell line and the most efficient photosensitizer in causing photoxidation of uric acid; nevertheless it was the only one characterized as being hydrophobic among the xanthenes studied here. On the other hand, it was observed that the halogen substituents increased the hydrophilicity and photodynamic activity, consistent with the cytotoxic experiments. Furthermore, the reactivity index parameters, electric dipole moment, molecular volume, and the frontier orbitals were also obtained by the Density Functional Theory (DFT). The lowest dipole moment and highest molecular volume ofRBcorroborate with its highest hydrophobicity due to heavy atom substituents like halogens, while the halogen substituents did not affect expressively the electronic features at all.

Selective Adsorption and Separation through Molecular Filtration by Hyperbranched Poly(ether amine)/Carbon Nanotube Ultrathin Membranes.

In response to the increasing public awareness of serious dye-contained wastewater contamination, we herein fabricated a novel anthracene-containing hyperbranched poly(ether amine) (hPEA-AN)/carbon nanotube (CNT) ultrathin membrane (UTM), which combined both the merits of the conventional dye adsorption strategy and membrane filtration process, to implement efficient selective adsorption of dye molecules and also the separation of dye mixtures by molecular filtration. Taking advantage of the π-π stacking interactions between anthracene and CNT sidewalls and hydrophobic interactions, CNTs were coated tightly with hPEA-AN to form the hPEA-AN@CNT complex, which can be well-dispersed very stably in water. The formation of the hPEA-AN@CNT complex was confirmed using X-ray photoelectron spectroscopy, Raman spectra, fluorescence spectra, and thermogravimetric analysis. Meanwhile, a simple filtration process was applied to prepare hPEA-AN@CNT UTMs with a thickness of 1.5 μm, which can be further cross-linked through photodimerization of anthracene moieties. The UTMs represented selective adsorption behaviors toward hydrophilic dyes even with similar backbones and the same charge states, namely, they showed high adsorption capacities (Qeq) toward eosin B, erythrosin B (ETB), 4',5'-dibromofluorescein, and Evans blue (EVB) dyes up to 300 μmol/g while showing low adsorption capacities toward calcein (Cal), methyl red, and Ponceau S dyes. On the basis of this unique selective adsorption, molecular filtration was then realized toward mixed ETB/Cal and EVB/Cal dyes, with a separation efficiency of up to 100% and regeneration without an obvious efficiency decrease.

Application of a non-hazardous vital dye for cell counting with automated cell counters

Recent advances in automated cell counters enable us to count cells more easily with consistency. However, the wide use of the traditional vital dye trypan blue (TB) raises environmental and health concerns due to its potential teratogenic effects. To avoid this chemical hazard, it is of importance to introduce an alternative non-hazardous vital dye that is compatible with automated cell counters. Erythrosin B (EB) is a vital dye that is impermeable to biological membranes and is used as a food additive. Similarly to TB, EB stains only nonviable cells with disintegrated membranes. However, EB is less popular than TB and is seldom used with automated cell counters. We found that cell counting accuracy with EB was comparable to that with TB. EB was found to be an effective dye for accurate counting of cells with different viabilities across three different automated cell counters. In contrast to TB, EB was less toxic to cultured HL-60 cells during the cell counting process. These results indicate that replacing TB with EB for use with automated cell counters will significantly reduce the hazardous risk while producing comparable results.

Supramolecular Networks of Hyperbranched Poly(ether amine) (hPEA) Nanogel/Chitosan (CS) for the Selective Adsorption and Separation of Guest Molecules

Supramolecular networks with selective adsorption for guest molecules were formed via dynamic hydrogen-bonding interactions between the carboxyl group-containing hyperbranched poly(ether amine) nanogels (hPEA-NG) and chitosan (CS). The hPEA-NG/CS supramolecular networks were physically cross-linked and were composed of hPEA-NGs dispersed within a crystallized CS matrix. An increasing CS content enhanced the mechanical properties of the hPEA-NG/CS supramolecular networks. The transparent hPEA-NG supramolecular networks did not disassemble in aqueous solutions with different pH values and organic solvents and were swollen with high weight fractions of water (WH2O = 0.95) in less than 30 s. The adsorptive behavior of seven fluorescein dyes and five azobenzene (azo) dyes onto the hPEA-NG/CS supramolecular networks was investigated. These hPEA-NG/CS supramolecular networks showed rapid adsorption for Rose Bengal (RB), Erythrosin B (ETB), Eosin B (EB), 4′,5′-dibromofluorescein (DBF), Ponceau S (PS) and Evans blue (EVB) dyes with high adsorption capacities (Qeq). The networks showed very low adsorption for calcein (Cal), fluorescein (FR), 4,5,6,7-tetrachlorofluorescein (TCF), and Bismarck brown (BBY) dyes. The adsorption process was found to follow pseudo-second-order kinetics. The different adsorptive behaviors for different dyes indicated the selective adsorption of the hPEA-NG/CS supramolecular networks for the azo and fluorescein dyes despite similar backbone structures and charge states. On the basis of the unique selective adsorption, the separation of mixtures of fluorescein dyes, such as RB/Cal, RB/FR, and PS/MR, was achieved using the hPEA-NG/CS supramolecular network as an adsorbent.