Pyronine B Research Articles

Preparation of flowerlike BiOBr/Bi2MoO6 composite superstructures and the adsorption behavior to dyes

Flowerlike BiOBr/Bi2MoO6 composite superstructures were synthesized by a simple solvothermal route with subsequent direct precipitation at room temperature, employing bismuth nitrate, sodium molybdate, and cetyltrimethylammonium bromide (CTAB) as the raw materials. The phase and the morphology of the as-prepared products were characterized by SEM, TEM, SAED, XRD and EDS. BET investigation proved the mesoporous structure of flowerlike BiOBr/Bi2MoO6 composite superstructures. It was found that the composite superstructures exhibited higher adsorption ability to methylene blue (MB) and pyronine B (PB) dyes from their solutions than single component (BiOBr or Bi2MoO6). As a case, the adsorption behavior of MB aqueous solution on BiOBr/Bi2MoO6 composite superstructures was detailedly studied, including the adsorption isotherm, kinetics and thermodynamic parameters. The results indicated that flowerlike BiOBr/Bi2MoO6 composite superstructures have potential applications in the field of wastewater treatment.

Spectroscopic insights on selfassembly and excited state interactions between rhodamine and phthalocyanine molecules

The absorption and fluorescence spectra as well as fluorescence lifetimes of tetrasulfonated zinc phthalocyanine ZnPc(SO3Na)4 were measured in the absence and presence of four rhodamine dyes, Rhodamine B (RB), Ethyl rhodamine B (ERB), Rhodamine 6G (R6G), Rhodamine 110 (R110), and Pyronine B (PYB). The ground state complexes of phthalocyanine–(Rhodamine)2 were observed which exhibit new absorption bands. The binding constants are all very large (0.86×105–0.22×108M−1), suggesting rhodamine–phthalocyanine pairs are very good combinations for efficient selfassembly. Both the fluorescence intensity and the lifetime values of ZnPc(SO3Na)4 were decreased by the presence of rhodamines. The structural effect of rhodamines on selfassembly is significant. The ground state binding and dynamic quenching capability is PYB>R6G>ERB>RB>R110. The dynamic fluorescence quenching is due to the photoinduced electron transfer (PET). The PET rate constant is very large and in the order of 1013M−1s−1, much greater than kf and kic (in the order of 108M−1s−1), which means that the PET efficiency is almost 100%. Therefore the non-covalent Pc–rhodamine is a very good pair of donor/acceptor for potential efficient solar energy conversion.

Modified electrical characteristics of Pt/n-type Ge Schottky diode with a pyronine-B interlayer

The electrical characteristics of a Pt/n-type Ge Schottky diode with a pyronine-B (PYR-B) interlayer prepared by spin coating was investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements. It was observed that the barrier height of Pt/PYR-B/n-type Ge (0.65eV) was higher than that of the conventional Pt/n-type Ge Schottky diode (0.58eV). This is attributed to the fact that the organic interlayer increases the effective barrier height by influencing the space-charge region of Ge. The introduction of the PYR-B interlayer led to a reduction of the interface state density in the Pt Schottky contact to n-type Ge. The electric field dependence of the reverse leakage current revealed that Schottky emission and Poole–Frenkel emission mechanisms dominated the reverse current in the Pt/n-type Ge and Pt/PYR-B/n-type Ge Schottky diodes, respectively.

Quick staining technique for myeloperoxidase using potassium iodide and oxidized pyronine B

Myeloperoxidase (MPO) staining has been important for the cytomorphological diagnosis and classification of leukemia. A novel staining method for MPO and its clinical application are presented in the report. Pyronine B (PyB), serving as a chromogenic reagent, was pre-oxidized to obtain stable oxidized Pyronine B solution. The MPO working solution for oxidized pyronine B method consisted of phosphate buffer solution, potassium iodide (KI) solution, and oxidized Pyronine B solution. The positive products of the oxidized Pyronine B method of MPO staining were vibrant red particles located in cytoplasm and the nucleus was stained bluish green. Bone marrow smears from 229 patients with acute leukemia or with grossly normal bone marrow were stained by both oxidized Pyronine B method and the conventional Washburn benzidine staining and a comparison revealed no significant difference in the positive detection rate between the two techniques. The new method eliminates the influence of the varying amount of H2O2 on MPO staining. With this method, the reagents were more stable and the staining procedure was simple and time-saving. This MPO staining technique is a better alternative than the conventional benzidine-based methods.

Structural and optical characterizations of pyronine B thin films and its photovoltaic applications

In this work, the organic thin films of pyronine B (PYR.B) were deposited by thermal evaporation technique under high vacuum (∼10 4 Pa). The crystal structure, examined by X-ray powder diffraction, indicates that the films are single phase with strong preferred (4 0 0) orientation. Scanning electron micrographs of the films indicate a clearly almost uniform distribution with large grain sizes in the range 5–10 μm. The molecular structure and electronic transitions of PYR.B were investigated by Fourier-transform infrared (FTIR). Fluorescence characteristic of PYR.B at room temperature (300 K) exhibits visible band peak located at 569.65 nm. The color parameters were extracted from the reflectance spectrum of PYR.B. The optical constants such as refractive and extinction indices were determined from the measured transmittance and reflectance spectra using the spectrophotometric method. The dependence of absorption coefficient on the photon energy was determined and the analysis of the result showed that the optical transition in PYR.B is allowed and direct. The current density–voltage ( J– V) characteristics in dark show the rectification effect due to the formation of Schottky barrier at Al/PYR.B interface. The photovoltaic parameters were calculated from the J– V characteristics under illumination through ITO and discussed in detail.

Concentration Dependence of the Photoluminescence Energy and Anisotropy from Dye Molecules and Dye Molecule - Zeolite Composites

We analyzed the photoluminescence (PL) peak shift and the anisotropy of dye molecules and dye molecule zeolite composites as function of the concentration of pyronine B (PyB) molecules. We used PyB dye molecules and zeolite L. The PL of PyB molecules was red-shifted with increasing concentration of PyB molecules. However the PL of PyB incorporated zeolite composite was independent of the concentration. The PL intensity anisotropy value also increased with increasing concentration in these composites. The anisotropy of zeolite dye composites was about 2.8 at high concentration; which is close to the theoretical anisotropy value of 3. Since the host zeolite protects dye molecules from aggregation, these results are di erent form the case of dye molecules in a solvent. In addition, we observed the con nement e ect of dye molecule zeolite composites from the blue shift of the PL spectrum.

Photoluminescence Study of Fluorophore-Containing Zeolite Rods

We have studied the photoluminescence (PL) from pyronine-B (PyB) dye molecules inserted into the pores of various zeolites with different pore sizes. We observed that the PL spectrum blueshifted as the pore size of the zeolite decreased. This can be explained by the quantum confinement effect. We also noticed that the luminescence of the dye molecules was affected by the type of solvent. In addition, we studied the optical anisotropy of PyB-containing zeolite rods by using polarized photoluminescence spectroscopy. A high anisotropic ratio of ∼9 was obtained from an oriented monolayer of PyB-containing zeolite L.

The conductance and capacitance–frequency characteristics of Au/pyronine-B/p-type Si/Al contacts

The rectifying junction characteristics of the organic compound pyronine-B (PYR-B) film on a p-type Si substrate have been studied. The PYR-B has been evaporated onto the top of p-Si surface. The barrier height and ideality factor values of 0.67±0.02eV and 2.02±0.03 for this structure have been obtained from the forward bias current–voltage (I–V) characteristics. The energy distribution of the interface states and their relaxation time have been determined from the forward bias capacitance–frequency and conductance–frequency characteristics in the energy range of ((0.42±0.02)−Ev)–((0.66±0.02)−Ev)eV. The interface state density values ranges from (4.21±0.14)×1013 to (3.82±0.24)×1013cm−2eV−1. Furthermore, the relaxation time ranges from (1.65±0.23)×10−5 to (8.12±0.21)×10−4s and shows an exponential rise with bias from the top of the valance band towards the midgap.

Fluorescence Determination of Artemisinin Using Cytochrome c as Catalyst and Pyronine B as Indicator

The cytochrome c-catalyzed fluorescence determination of artemisinin (qinghaosu, QHS) was developed using pyronine B (PB) as substrate. The interaction between cytochrome c and QHS was an enzyme-substrate model. The kinetic studies demonstrated that the steady-state catalytic rate depended upon enzyme and substrate concentrations, and the Michaelis-Menten parameters, K m, V max, and K cat were 3.3×10 −5 M, 5.4×10 −6 M s −1 and 13.5 s −1, respectively. Catalytic activity of cytochrome c was inhibited in the presence of deactivated agents CN − and ethanol. Under optimal conditions (pH 5.3, 25°C and 7.6×10 −8 to 1.1×10 −6 M, the detection limit (3σ) was as low as 7.2×10 −9 M and the percent recovery range was 96.3%–106.8%. The proposed method was applied to detect the concentration of QHS in the media of plasma and urine.

Utilization of Pyronine B as Voltammetric Probe for the Determination of DNA

The electrochemical behaviors of the interaction of pyronine B (PB) with DNA were investigated on the mercury drop working electrode. In pH 2.0 Britton‐Robinson (B‐R) buffer solution, PB can be easily reduced on the mercury electrode and had a well‐defined voltammetric reductive wave at −0.86 V (vs. saturated calomelelectrode, SDE). On the addition of DNA into the PB solution, the reductive peak current of PB decreased with the positive movement of the peak potential and without the appearance of new peaks. The result showed that a new supramolecular complex was formed via intercalation of PB with DNA, which can't be reduced on the Hg electrode. The conditions of interaction and the electrochemical detection were carefully investigated. Under the optimal conditions the decrease of peak current was proportional to the concentration of DNA in the range of 1.0∼30.0 mg/L with the linear regression equation as ΔIp″(nA)=51.84C (mg/L)–94.97 (n=13, γ=0.993) and the detection limit was 0.90 mg/L. The interaction mechanism was discussed with the aggregation of DNA‐PB supramolecular complex and the stoichiometry of the supramolecular complex was calculated with the binding number as 3 and the binding constant as 1.61×1015.

Spectrofluorimetric determination of artemisinin with pyronine B as the substrate for horseradish peroxidase

Enzyme-catalytic fluorescence determination of artemisinin (qinghaosu, QHS) was developed using pyronine B (PB) as substrate of horseradish peroxidase (HRP). The interaction between HRP and QHS was an enzyme-substrate model. The catalytic characteristic of HRP in the oxidation reaction, in which the fluorescence of PB was decreased in the presence of QHS, was studied. The steady-state catalytic rate depended upon enzyme and substrate concentrations, and the Michaelis-Menten parameters K m Vmax and K cat were 8.4×10−5 mol · L−1, 7.4×10−6 mol · L−1v s−1 and 50.23 s−1. The catalytic activity of enzyme was inhibited in the presence of deactivated agents and at high temperature, respectively. Under optimum conditions, linear relationship between fluorescence intensity change (F 0- F) of pyronine B and concentration of QHS was in the range of 1.41×10−7-1.27×10−6 mol · L−1. The detection limit (3σ) was determined to be 2.7×10−8mol· L−1. The proposed method was applied to the concentration determination of QHS in the media of plasma or urine samples.

Cetyltrimethylammonium bromide sensitized resonance light-scattering of nucleic acid–Pyronine B and its analytical application

This is the first report on the determination of nucleic acids with Pyronine B (PB) sensitized by cetyltrimethylammonium bromide (CTMAB) with resonance light-scattering (RLS) technique. Under the experimental conditions (1×10 −5 mol l −1 PB, 1×10 −5 mol l −1 CTMAB, pH 7.4, at room temperature, ionic strength 0.02 mol l −1 NaCl), the interaction of PB with DNA sensitized by CTMAB results in enhanced RLS signals at 328 and 377 nm in the enhanced regions. It was found that the enhanced RLS intensity at 328 nm was proportional to the concentration of DNA in the suitable ranges. The linear range of this assay is 0.0–1.2 μg ml −1 for calf thymus, 0.0–0.8 μg ml −1 for fish sperm DNA (fsDNA), and 0.04–1.4 μg ml −1 for yeast RNA, respectively. The detection limits (3 σ) are 6.1 ng ml −1 for calf thymus DNA (ctDNA), 11.2 ng ml −1 for fish sperm DNA, and 8.6 ng ml −1 for yeast RNA, respectively. Six synthetic samples were determined satisfactorily. This method is simple, rapid and the dye is inexpensive and stable.

Studies on Mimic Peroxidase Behaviors of Molybdenum(VI)–Sodium Dodecyl Sulphate Complex for the Determination of Hydrogen Peroxide and Glucose

Some transition metals–sodium dodecyl sulphate (M–SDS) complexes are used to mimic the active group of peroxidase. The catalytic characteristics of these mimic‐enzymes in the oxidation reaction of fluorescence substrate, pyronine B (PB), with hydrogen peroxide have been studied. Though the catalytic activities of M–SDS complexes are much lower than horseradish peroxidase (HRP), they can catalyze the oxidation reaction of PB with hydrogen peroxide leading to fluorescence quenching of PB. Mo(VI)–SDS complex exhibited the highest catalytic activity among same type mimic enzymes. Under optimum conditions, linear relationship between fluorescence quenching F 0/F and concentration of H2O2 is in the range of 0.0–8.6 × 10−7 M. By coupling this mimic catalytic reaction with the glucose oxidase, glucose can be detected. Linear relationship between F 0/F and concentration of glucose is in the range of 0.0–1.4 × 10−7 M. The method has been applied to the determination of glucose in human serum and the results are in good agreement with the method of phenol‐4‐aminoantipyrine.

Abstracts

STUDIES ON MIMIC PEROXIDASE BEHAVIORS OF MOLYBDENUM(VI)–SODIUM DODECYL SULPHATE COMPLEX FOR THE DETERMINATION OF HYDROGEN PEROXIDE AND GLUCOSE by Li‐Hua Chen, Chemical School, Nankai University, Tianjin, 300071, China and Chemical Department, Jishou University, Jishou City, Hunan, 416000, China; Liu‐Zhan Liu and Han‐Xi Shen, Chemical School, Nankai University, Tianjin, 300071, China ABSTRACT: Some transition metals–sodium dodecyl sulphate (M–SDS) complexes are used to mimic the active group of peroxidase. The catalytic characteristics of these mimic‐enzymes in the oxidation reaction of fluorescence substrate, pyronine B (PB), with hydrogen peroxide have been studied. Though the catalytic activities of M–SDS complexes are much lower than horseradish peroxidase (HRP), they can catalyze the oxidation reaction of PB with hydrogen peroxide leading to fluorescence quenching of PB. Mo(VI)–SDS complex exhibited the highest catalytic activity among same type mimic enzymes. Under optimum conditions, linear relationship between fluorescence quenching F 0/F and concentration of H2O2 is in the range of 0.0–8.6 × 10−7 M. By coupling this mimic catalytic reaction with the glucose oxidase, glucose can be detected. Linear relationship between F 0/F and concentration of glucose is in the range of 0.0–1.4 × 10−7 M. The method has been applied to the determination of glucose in human serum and the results are in good agreement with the method of phenol‐4‐aminoantipyrine. Analytical Letters, 37(4), 561–573, 2004

Mn(II)–sodium dodecyl sulphate complex mimic enzyme-catalyzed fluorescence quenching of Pyronine B by hydrogen peroxide

Mn(II)–sodium dodecyl sulphate complex (Mn(II)–SDS) is used to mimic the active group of peroxidase. The catalytic characteristic of this mimic enzyme catalyst in the oxidation reaction of fluorescence substrate, tetraethyldiaminoxanthyl chloride (Pyronine B (PB)), with hydrogen peroxide has been studied. The experimental results show that Mn(II)–SDS complex has similar catalytic activity that of peroxidase. The steady-state catalytic rate depends upon mimic enzyme and substrate concentrations, and the Michaelis–Menten parameters K m, V max and K cat are 7.6×10 −6 M, 7.9×10 −7 M s −1 and 7.9 s −1, respectively. The catalytic activity of Mn(II)–SDS complex is compared with those of HRP and Hemin. Though the catalytic activity of Mn(II)–SDS complex is 15.9% of that of HRP, it can catalyze the oxidation reaction of PB with hydrogen peroxide lead to fluorescence quenching of PB. Under optimum conditions, linear relationship between fluorescence quenching F 0/ F and concentration of H 2O 2 is in the range of (0.0–3.6) × 10 −7 M. The detection limit is determined to be 3.0×10 −9 M. By coupling this mimic catalytic reaction with the catalytic reaction of glucose oxidase (GOD), glucose can be detected. Linear relationship between F 0/ F and concentration of glucose is in the range of (0.0–1.4) × 10 −7 M. The detection limit is determined to be 4.2×10 −9 M. This method is applied to the determination of glucose in human serum and the results are in good agreement with the phenol-4-aminoantipyrine (4-AAP).

A kinetic and equilibrium study of the inclusion of pyronine B by β- and γ-cyclodextrin

Temperature-jump visible spectrophotometric studies show the dye pyronine B (PB) in its monovalent cationic form to be included by γ-cyclodextrin (γCD) in a fast step to form a 1:1 complex (PB·γCD), which is followed by the slower formation of the 2:1 complex (PB)2·γCD, in which pyronine B dimerises: PB +gamma;CD [graphic omitted] PB·gamma;CD (K1)(fast)(1), PB + PB·γCD [graphic omitted] (PB)2·γCD (K2)(slow)(2) where, in aqueous 1.00 mol dm–3 NaCl at pH 5.70 and 298.2 K, K1=(4.3 ± 0.1)× 102 dm3 mol–1, K2=(1.28 ± 0.04)× 105 dm3 mol–1, k2=(8.2 ± 0.2)× 108 dm3 mol–1 s–1 and k–2=(6.40 ± 0.05)× 103 s–1. In the presence of βCD only the formation of PB·βCD is detected and is characterised by k1=(1.1 ± 0.1)× 108 dm3 mol–1 s–1 and k–1=(1.5 ± 0.5)× 104 s–1. Equilibrium u.v.–visible spectrophotometric measurements are consistent with these kinetic data. No inclusion of PB by αCD was detected. These data are compared with those characterising related systems. The dimerisation of PB in the absence of γCD is fast, an observation which forms the basis for some of the mechanistic deductions concerning the formation of (PB)2·γCD, and also for a reassessment of some mechanistic interpretion in earlier studies.

Regulation of Plant Virus Multiplication by Environmental Factors. Resistance of Tomato Cultivars to Tobacco Mosaic Virus II

Tomato cultivars Zuiko (ZK), resistant to TMV causing top-necrosis by infection with TMV, Fukuju No. 2 (F2), susceptible to TMV causing mosaic, strains GCR 236, GCR 237, GCR 254, and GCR 267, resistant to TMV causing no symptoms, were used. They were tested whether or not the induced resistance does occur by changing temperatures during incubation following inoculation, by heating tomato seedlings as a shock at 45°C for 10 min immediately after inoculation, by introducing dyes, acridine orange (AO), azure B (AB), and pyronine B (PB), into tomato seedlings, and by introducing the infected tomato extract.At 25°C, TMV concentration in ZK was 2% of that in F2, whereas it reached almost 60% at 20°C, showing that ZK was not resistant at a low temperature below the optimum for tomato growth. Heat shock induced the reduced amount of TMV in ZK as compared with non-treatment, but did not in GCR 236, GCR 237, and GCR 267. Thus, ZK alone showed an induced resistance by this treatment. ZK, GCR 236, GCR 237, and GCR 254, all showed a decrease in TMV concentration by introducing dyes through root, especially by 10 ppm AO. However, F2 cultured in 10 ppm AO showed no alteration in TMV concentration comparing with that cultured in water. When the extract obtained from non-infected ZK which was cultured in 10 ppm AO, was mixed with TMV and the mixture was inoculated on the leaves of bean (Phaseolus vulgaris), AO absorbed-ZK extract showed no inhibitory activity to TMV infection. These facts indicate that AO did not directly inactivate TMV, but induced a highly resistance in ZK except F2. F2 which had absorbed the infected F2 extract, reduced TMV concentration, but that absorbed non-infected F2 extract or infected ZK extract did not so much. ZK did not reduce TMV concentration by absorbing F2 extract or non-infected ZK extract, but did a little by absorbing infected ZK extract.From these results, induction of resistance in tomato cultivars caused by the environmental factors is discussed.