Eosin B Research Articles

Spectral, thermal and morphological studies of fluorescent dye grafted diblock copolymers

The preparation of the fluorescent diblock copolymer was carried out between poly(tetrahydrofuran) (PTHF) and poly(ε-caprolactone) (PCL) via bulk and ring-opening polymerization (ROP) method by using two different dyes such as fluorescent methyl red (MR) and eosin b (EB) as lone chemical initiators at 160 °C under N2 atmosphere for two hours. All the prepared homopolymer and diblock copolymer were examined by NMR and FT-IR like analytical instruments. The molecular weight of the diblock copolymer was higher than the homopolymer. The TGA results showed that the thermal stability of PTHF in the diblock copolymer was lower when compared with dye end capped PCL. In this work, the ROP efficiency of two different dye-based initiators is compared and their results are critically analyzed. The –OH group-containing EB exhibited excellent results. The dye conjugated polymer was prepared by a single-step process.

Controlled growth of AgI nanoparticles on hollow WO3 hierarchical structures to act as Z-scheme photocatalyst for visible-light photocatalysis

Controllable fabrication of nanomaterials with hierarchical architecture have received much attention in the field of photocatalysis due to their enhanced light-harvesting efficiency. Moreover, fabricating direct Z-scheme heterojunctions havebeenproven to be effective way to enhance the photocatalytic performance of photocatalysts. Herein, hierarchically hollow WO3 nanoflower was successfully synthesized by a simple hydrothermal treatment of tungsten chloride (WCl6) in ethanol solution. Decoration of the obtained WO3 with AgI nanoparticles in situ can form the Z-scheme AgI/WO3 hollow hierarchical nanoflowers (AgI/WO3 HHNFs). The AgI/WO3 HHNFs exhibited excellent photocatalytic activity and remarkable stability for the degradation of tetracycline hydrochloride (TC-HCl) and Eosin B (EB) under the irradiation of a low energy consume light (LED lamp, 5 W). Interestingly, compared to pure AgI nanoparticles, 3D hollow WO3 nanoflowers and AgI/WO3 nanosheets, the AgI/WO3 HHNFs revealed conspicuously enhanced photocatalytic activity. Thisphenomenon could be associated to three aspects, namely the high light-harvesting efficiency, increased light trapping and scattering capability and strongly coupled Z-scheme heterointerface, which effectively improved the photoelectron-hole sepreation efficiency. Our work therefore provide a novel insight for the fabrication of 3D hollow hierarchical structures.

Novel Ag2O-Ga2O3 type II p-n heterojunction as an efficient water cleanser for green cleaning technology

Ag2O-Ga2O3 based type II p-n nanoheterojunctions were fabricated using ex-situ chemical reduction technique with different densities of Ag2O attachment to gallia surface. A systematic optimization was carried out to establish the best performing junction aiming for the photodegradation of the noxious organic dye methyl orange (MO). Thorough theoretical and experimental studies were performed to determine relative band positions and ensure charge transfer between the counterparts. Favorable alignment of the electronic bands of Ag2O and Ga2O3 was identified as a key factor for the prompt separation of photogenerated e−/h+ pair leading to a faster decomposition of hazardous dyes. The optimized sample also performed remarkably fast in degrading carcinogenic phenol and other dyes like rhodamine B (RhB), aniline blue (AB), eosin B (EB) and mixtures of dyes with different ionic identities. Additional advantages of these catalysts were reflected in the retainment of catalytic efficiency over multiple water disinfection cycles and its performance in active media of different pH values was observed. With high degradation rate constants of 0.4158, 0.3306, 0.2436 and 0.207 min−1 for RhB, AB, MO, EB respectively and multidimensional performance as green cleaning agent, this newly explored Ag2O3-gallia nanoheterojunction is identified as a strong candidate for future water cleaning technology.

Fluorimetric determination of β-carotene in food samples using a fluorescent dye

A simple, sensitive, and selective fluorimetric method is reported for the determination of β-carotene in various food samples. Three fluorescent dyes, including fluorescein (F), eosin B (EB), and Congo red (CR), were characterized in a series of measurements to optimize the analytical response for the reliable, suitable, and sustainable determination of β-carotene. 3′,6′-Dihydroxyspiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one, commonly known as fluorescein, was selected for the fluorimetric determination of β-carotene using a phosphate buffer. Under the optimum experimental conditions, β-carotene was determined across a range from 0.54 to 536.87 mg L−1 with a detection limit equal to 0.47 mg L−1. The novel method was demonstrated to be easy to use, cost effective, rapid, and less complex compared to a standard protocol that involves a time-consuming extraction followed by an expensive HPLC determination.

Highly efficient and selective removal of low-concentration antibiotics from aqueous solution by regenerable Mg(OH)2

The prevalent presence of fluoroquinolone antibiotics in aquatic environments has attracted considerable attention because of their harmful effects on humans and the ecological environment. Magnesium hydroxide nanocrystals were found to act as a simple and effective adsorbent to remove low-concentration ciprofloxacin (CIP) in aqueous solution. The as-prepared Mg(OH)2 nanocrystals exhibited excellent CIP adsorption performance and high selectivity toward CIP molecules compared with other antibiotics or aromatics, e.g., norfloxacin (NOR) and eosin B (EB). The adsorbent showed pH-dependent adsorption, indicating that the adsorption process is probably dominated by an electrostatic interaction mechanism. In addition, structural analysis of the adsorbent indicated that coordination and hydrogen bonding between CIP and Mg(OH)2 nanocrystal might also be involved in the adsorption process. Moreover, the adsorbent could be easily recovered by pyrolysis and hydration without significant reduction of adsorption capacity. The superior adsorption behavior of Mg(OH)2 nanocrystal indicates that it may serve as a potential adsorbent material candidate for the selective removal of CIP from aquatic environments.

Solution combustion-derived ZnO nanoparticles for photoanode of solar cells

ZnO nanoparticles (NPs) were synthesized using solution combustion method with different urea percent (UP) i.e. U1, U2, U3 and U4. The obtained ZnO NPs were characterized using X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), UV–Vis spectroscopy and photoluminescence spectroscopy (PL). XRD analysis confirmed the wurtzite structure of the prepared ZnO NPs and the estimated average crystallite size reduced from 28.03 nm to 17.33 nm with increasing of UP. HR-TEM image showed an irregular spherical shape for the prepared ZnO NPs. The absorption spectra analysis exhibited that the optical energy band gap (Eg) for the ZnO NPs increased with increasing of UP from 2.84 eV to 3.13 eV. Two groups (I and II) of dye sensitized solar cell (DSSCs) device based on the synthesized ZnO NPs were fabricated. In group I, 0.32 mM Eosin B (EB) used as photosensitizer for the samples U1, U2, U3 and U4, which showed that the overall conversion efficiency (η) increased from 0.09% to 0.13%, under a light intensity of 100 mW/cm2 due to the increasing of UP. Group II, different photosensitizer EB, Eosin Y (EY) and Rhodamine B (RB) used to sensitized the U4, where the EY exhibited the best all of them. The conversion efficiency presented a significant improvement from 0.13 to 1.26%. The combustion method can be considered as a promising method to produce good photoanode semiconductors such ZnO subsequently increase the efficiency of the solar cell.

Synthesis and Characterization of Zno Nanoparticles Using Hydrothermal and Sol-Gel Techniques for Dye-Sensitized Solar Cells

ZnO nanoparticles (ZnO NPs) were synthesized using hydrothermal and sol-gel techniques using zinc acetate dihydrate (Zn (CH3COO)2.2H2O) as a row material and methanol as a solvent. The structural properties of ZnO NPs were studied using EDX, XRD, TEM, and the optical properties were characterized using UV-VIS and PL spectroscopies. The synthesized ZnO NPs showed high purity and revealed a wurtzite (hexagonal) crystal structure with particle size (D) ranged from 25 nm to 28 nm. The UV-VIS absorption spectra of ZnO NPs samples and sensitizing dyes were performed. The obtained ZnO NPs exhibited the direct optical bandgap 3.15 eV. Dye-sensitized solar cells (DSSCs) were fabricated using synthesized ZnO NPs as a semiconducting layer, which was dyed with different low cost dyes such as Eosin B (EB), Eosin Y (EY) and Rhodamine B (RB) that was used to sensitize the photoanode (ZnO NPs). The experimental results showed a significant efficiency for the fabricated DSSCs of synthesized ZnO NPs via sol gel technique comparing to hydrothermal technique. The EY dye exhibited the best performance among others, where a conversion efficiency showed a noteworthy improvement from 0.12 to 1.08 %.

Fluorescent resonance energy transfer of organic fluorescent dyes with gold nanoparticles and their analytical application

We report five effective fluorescence resonance energy transfer (FRET) systems based on gold nanoparticles (AuNPs) and organic fluorescent dyes, including ionic [fluorescein sodium (FS) and Eosin B (EB)] and cationic [rhodamine 6G (Rh6G), acridine orange (AO), and safranine T (ST)] fluorescent dyes. The fluorescence intensity of the five FRET systems demonstrates that efficient quenching is possible. The quenching efficiencies of Rh6G and FS by FRET were nearly 100%, 89% for AO, 60% for EB, and 55% for ST. A series of UV absorbance spectra and fluorescence emission spectra were used to explain the mechanism of fluorescence quenching. We found that there were different degrees of overlap between the absorption spectrum of the AuNPs and the emission spectrum of fluorescence dyes. This outcome indicates that highly efficient FRET is the possible mechanism of fluorescence quenching. We applied the FRET system to establish a sensitive and simple strategy for the determination of mercury (Hg2+). The maximum excitation was at 523 nm (λex = 523 nm). The enhanced fluorescence intensity at 551 nm was proportional to the concentration of Hg2+ with a range of 0.44–100 nmol L−1. The detection limit was 0.13 nM. The linear regression equation was ΔF = 27.05c (nmol L−1) − 79.88, and the regression coefficient was 0.9954. The proposed method has high sensitivity and convenience and does not require complex and expensive instruments.

A simple approach for the sonochemical loading of Au, Ag and Pd nanoparticle on functionalized MWCNT and subsequent dispersion studies for removal of organic dyes: Artificial neural network and response surface methodology studies

In this study, the artificial neural network (ANN) and response surface methodology (RSM) based on central composite design (CCD) were applied for modeling and optimization of the simultaneous ultrasound-assisted removal of quinoline yellow (QY) and eosin B (EB). The MWCNT-NH2 and its composites were prepared by sonochemistry method and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analysis’s. Initial dyes concentrations, adsorbent mass, sonication time and pH contribution on QY and EB removal percentage were investigated by CCD and replication of experiments at conditions suggested by model has results which statistically are close to experimented data. The ultrasound irradiation is associated with raising mass transfer of process so that small amount of the adsorbent (0.025 g) is able to remove high percentage (88.00% and 91.00%) of QY and EB, respectively in short time (6.0 min) at pH = 6. Analysis of experimental data by conventional models is good indication of Langmuir efficiency for fitting and explanation of experimented data. The ANN based on the Levenberg–Marquardt algorithm (LMA) combined of linear transfer function at output layer and tangent sigmoid transfer function at hidden layer with 20 hidden neurons supply best operation conditions for good prediction of adsorption data. Accurate and efficient artificial neural network was obtained by changing the number of neurons in the hidden layer, while data was divided into training, test and validation sets which contained 70, 15 and 15% of data points respectively. The Average absolute deviation (AAD)% of a collection of 128 data points for MWCNT-NH2 and composites is 0.58%.for EB and 0.55 for YQ.

Novel β-cyclodextrin-eosin conjugates.

Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

Rapid adsorption of ternary dye pollutants onto copper (I) oxide nanoparticle loaded on activated carbon: Experimental optimization via response surface methodology

Rapid adsorption of hazardous anionic dyes sunset yellow (SY), eosin B (EB) in the presence of cationic dye i.e. methylene blue (MB) from ternary solutions using copper oxide nanoparticle loaded on activated carbon(Cu2 O-NP-AC) was well investigated and elucidated. The synthesized adsorbent was well characterized using various analytical techniques such as X-ray diffraction (XRD), and FE-SEM. The impact of effective parameters such as pH, sonication time, adsorbent dosage and initial dye concentration was well studied and optimized using central composite design superimposed with response surface methodology. The numerical optimization revealed that the optimum removal (>96.0%) for all dyes were achieved using of 0.025g, 25, 15and15mgL−1 of SY, EB and MB after 4min sonication at pH of 5.0at above conditions. The adsorption equilibirium and kinetic data was well fitted and found to be in good agreement with Langmuir and pseudo-second order respectively. The maximum adsorption capacities SY, EB and MB were 113, 137 and 110mgg−1, respectively.

Selective adsorption and separation of organic dyes from aqueous solution on polydopamine microspheres

Polydopamine (PDA) microspheres, synthesized by a facile oxidation polymerization route, were evaluated as a potential adsorbent for selective adsorption and separation of organic dyes. The adsorption processes towards nine water-soluble dyes (anionic dyes: methyl orange (MO), eosin-Y (EY), eosin-B (EB), acid chrome blue K (ACBK), neutral dye: neutral red (NR), and cationic dyes: rhodamine B (RhB), malachite green (MG), methylene blue (MB), safranine T (ST)) were thoroughly investigated. The adsorption selectivity of organic dyes onto PDA microspheres was successfully applied for the separation of dyes mixtures. Various influential factors such as solution pH, temperature, and contact time were employed to ascertain the optimal condition for adsorption of representative organic dyes including MB, MG and NR. The pseudo-first-order and pseudo-second-order kinetics models were used to fit the adsorption kinetics process. Five isothermal adsorption models (Langmuir, Dubnin–Radushkevich, Temkin, Freundlich and Harkins–Jura) were used to investigate the adsorption thermodynamics properties. The results showed that the PDA microspheres owned good selective adsorption ability towards cationic dyes. The adsorption kinetics process conformed to the pseudo-second-order kinetics model and the Langmuir isotherm model was more appropriate for tracing the adsorption behavior than other isotherm models. Thus, we can conclude PDA microspheres may be a high-efficiency selective adsorbent towards some cationic dyes.

Highly efficient simultaneous ultrasonic assisted adsorption of brilliant green and eosin B onto ZnS nanoparticles loaded activated carbon: Artificial neural network modeling and central composite design optimization

In this work, central composite design (CCD) combined with response surface methodology (RSM) and desirability function approach (DFA) gives useful information about operational condition and also to obtain useful information about interaction and main effect of variables concerned to simultaneous ultrasound-assisted removal of brilliant green (BG) and eosin B (EB) by zinc sulfide nanoparticles loaded on activated carbon (ZnS-NPs-AC). Spectra overlap between BG and EB dyes was extensively reduced and/or omitted by derivative spectrophotometric method, while multi-layer artificial neural network (ML-ANN) model learned with Levenberg–Marquardt (LM) algorithm was used for building up a predictive model and prediction of the BG and EB removal. The ANN efficiently was able to forecast the simultaneous BG and EB removal that was confirmed by reasonable numerical value i.e. MSE of 0.0021 and R2 of 0.9589 and MSE of 0.0022 and R2 of 0.9455 for testing data set, respectively. The results reveal acceptable agreement among experimental data and ANN predicted results. Langmuir as the best model for fitting experimental data relevant to BG and EB removal indicates high, economic and profitable adsorption capacity (258.7 and 222.2mgg−1) that supports and confirms its applicability for wastewater treatment.

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.

Sugar uptake in the Aril of litchi fruit depends on the apoplasmic post-phloem transport and the activity of proton pumps and the putative transporter LcSUT4.

The post-phloem unloading pathway and the mechanism of sugar accumulation remain unclear in litchi fruit. A combination of electron microscopy, transport of phloem-mobile symplasmic tracer (carboxyfluorescein, CF) and biochemical and molecular assays was used to explore the post-phloem transport pathway and the mechanism of aril sugar accumulation in litchi. In the funicle, where the aril originates, abundant plasmodesmata were observed, and CF introduced from the peduncle diffused to the parenchyma cells. In addition, abundant starch and pentasaccharide were detected and the sugar concentration was positively correlated with activities of sucrose hydrolysis enzymes. These results clearly showed that the phloem unloading and post-phloem transport in the funicle were symplastic. On the other hand, imaging of CF showed that it remained confined to the parenchyma cells in funicle tissues connecting the aril. Infiltration of both an ATPase inhibitor [eosin B (EB)] and a sucrose transporter inhibitor [p-chloromercuribenzene sulfonate (PCMBS)] inhibited sugar accumulation in the aril. These results indicated an apoplasmic post-phloem sugar transport from the funicle to the aril. Although facilitated diffusion might help sucrose uptake from the cytosol to the vacuole in cultivars with high soluble invertase, membrane ATPases in the aril, especially tonoplast ATPase, are crucial for aril sugar accumulation. The expression of a putative aril vacuolar membrane sucrose transporter gene (LcSUT4) was highly correlated with the sugar accumulation in the aril of litchi. These data suggest that apoplasmic transport is critical for sugar accumulation in litchi aril and that LcSUT4 is involved in this step.

Hyperbranched Poly(ether amine) (hPEA)/Poly(vinyl alcohol) (PVA) Interpenetrating Network (IPN) for Selective Adsorption and Separation of Guest Homologues

We here reported that hyperbranched poly(ether amine) (hPEA) and poly(vinyl alcohol) (PVA) interpenetrating network (hPEA/PVA-IPN) can be used for the selective adsorption and separation of guest homologues. A series of hyperbranched poly(ether amine) and poly(vinyl alcohol) interpenetrating networks (hPEA/PVA-IPNs) were fabricated by introducing poly(vinyl alcohol) chains into network of hyperbranched poly(ether amine), in which two independent networks of hyperbranched poly(ether amine) and poly(vinyl alcohol) were cross-linked through photodimerization of coumarin groups of hyperbranched poly(ether amine) and aldol condensation reaction between hydroxyl groups of poly(vinyl alcohol) and glutaraldehyde, respectively. The mechanical strength of interpenetrating networks can be enhanced by the introduction of poly(vinyl alcohol), and the tensile strength of interpenetrating networks increased with tens of times in compared with the pure hyperbranched poly(ether amine) network. The adsorption behavior of seven fluorescein dyes sharing with the same backbone and charge state onto hyperbranched poly(ether amine) and poly(vinyl alcohol) interpenetrating networks was then investigated in detail. Regardless of their charge states, these interpenetrating networks exhibited the quick adsorption to Rose Bengal (RB), Erythrosin B (ETB), Eosin B (EB), 4',5'-dibromofluorescein (DBF), and 4,5,6,7-tetrachlorofluorescein (TCF), with high adsorption capacity (Qeq) and very low adsorption of Calcein (Cal) and fluorescein (FR). The adsorption process was found to follow the pseudo-second-order kinetics, and the introduction of poly(vinyl alcohol) has no obvious effect on the adsorption behavior in this study. The big difference in the adsorption is indicative of the selective adsorption of hyperbranched poly(ether amine) and poly(vinyl alcohol) interpenetrating networks to fluorescein dyes. Based on the unique selective adsorption, the separation of several mixtures of fluorescein dyes such as RB/Cal, RB/FR, ETB/FR, and ETB/Cal was achieved by using hPEA/PVA-IPN as adsorbent.

Synthesis Of Air Stable Copper Nanoparticles And Their Use In Catalysis

The undertaken study describes synthesis of air resistant copper nanoparticles (Cu NPs) in an aqueous phase using sodium borohydride as a reducing agent via chemical reduction method. The hydrosol has resistant to oxidation by atmospheric oxygen for several days. The air stability was induced by capping Cu NPs with anionic surfactant “sodium dodecyl sulfate (SDS)”. Ascorbic acid was used as an antioxidant. These Cu NPs were characterized by ultraviolet-visible (UV-VIS) spectroscopy, which contributed towards the understanding of surface plasmon resonance (SPR) generation and optical behavior of Cu NPs. It was used as an optical tracer for size control and confirmation of Cu NPs and was found to be affected by various parameters like reaction time, pH, concentration of copper sulfate and the surfactant SDS. SPR peaks were found to shift from 597 to 569 nm, while apparent color changes from yellow to brick red. Further characterization studies were carried out by using fourier transform infrared (FT-IR) spectroscopy to investigate the co-ordination between Cu NPs and SDS. X-ray diffraction (XRD) was used for phase purity of Cu NPs. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used the size and morphological characterization. The average size of the Cu NPs was found to be 15 nm in diameter with an average height of 14 nm. The Cu NPs showed excellent catalytic activity in the reductive degradation of Eosin B (EB) dye in just 16 sec of reaction time and maintained their catalytic activity when reused multiple times. The degradation rate was found to follow first order reaction kinetics with the EB degradation. The Cu NPs enhanced the rate of EB degradation 30 times more than the control test. Copper was found an attractive catalyst in the nanosize regimes. The Cu NPs are more economical as compared to noble metals. The Cu NPs are expected to be suitable alternative and play an imperative role in the fields of catalysis and environmental remediation.

Synthesis and Characterization of Highly Efficient Nickel Nanocatalysts and Their Use in Degradation of Organic Dyes

The present study describes the synthesis of highly active and ordered structures of nickel nanocatalysts by a facile, green, and economically viable approach. The study reveals efficient catalytic activity for the degradation of a number of toxic organic dyes, such as eosin-B (EB), rose bengal (RB), eriochrome black-T (ECBT), and methylene blue (MB). The stable ordered nickel nanostructure (Ni NSs) arrays were prepared via a modified hydrazine reduction route with unique and controlled morphologies in a lyotropic liquid crystalline medium using a nonionic surfactant (Triton X-100). Characterization and optimization studies for the fabricated Ni NSs involving their surface binding interactions, size, and morphologies were carried out using UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM).

Negative staining of lipopolysaccharides on polyacrylamide gels by using eosin B

A sensitive and simple technique for the negative detection of lipopolysaccharides (LPSs) following polyacrylamide gel electrophoresis (PAGE) using eosin B (EB) was developed. After electrophoresis, gels were fixed, stained, and developed within 30min to achieve transparent and colorless LPS bands under opaque gel matrix background. As low as 20 to 40ng of total LPSs could be detected, which is 4-fold more sensitive than those of the widely used silver stain developed by Fomsgaard and coworkers and imidazole–zinc (IZ) negative stain. For its sensitivity and brevity, this stain may be a practical method for LPS determination in the routine laboratory.

Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles

We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15 s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well.