It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an...It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.展开更多
Adsorption of Neutral Red (NR) onto peanut husk in aqueous solutions was investigated at 295 K. Experiments were carried out as function of pH, adsorbent dosage, contact time, and initial concentration. The equilibriu...Adsorption of Neutral Red (NR) onto peanut husk in aqueous solutions was investigated at 295 K. Experiments were carried out as function of pH, adsorbent dosage, contact time, and initial concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, and Toth isotherm models. The results indicated that the Toth and Langmuir models provided the best correlation of the experimental data. The adsorption capacity of peanut husk for the removal of NR was deter...展开更多
The earthworm Metaphire posthuma were used as a model to assess the toxic potential of cadmium incorporated into the soil by environmental or human activities. The retention period of neutral red in the lysosomes ...The earthworm Metaphire posthuma were used as a model to assess the toxic potential of cadmium incorporated into the soil by environmental or human activities. The retention period of neutral red in the lysosomes of the coelomocytes was used as a biomarker. The viability of harvested coelomocytes by a non_invasive extrusion protocol was 93% with no alteration by the dye during experimentation. The control cells retained dye for 119 and 121 min in normal soil and KCl, respectively, whereas a linear decline in the retention time in the treated earthworm coelomocytes was observed. This illustrated that the presence of cadmium caused damage to the lysosomes of the coelomocytes.展开更多
A voltammetric study of the interaction of neutral Red(NR) with DNA at a gold electrode in a phosphate buffer solution is described. After adding DNA in an NR solution, the reduction peak current of NR decreases. The ...A voltammetric study of the interaction of neutral Red(NR) with DNA at a gold electrode in a phosphate buffer solution is described. After adding DNA in an NR solution, the reduction peak current of NR decreases. The binding mechahisms of NR to DNA in different pH ranges are different. The reduction peak potential of NR in a pH 7.0 phosphate buffer solution in the presence of DNA shifts positively, indicating that the binding of NR to DNA is intercalation action, but at pH=6.0 the reduction peak potential of NR shifts negatively, indicating that the binding of NR to DNA is electrostatic action. The formed complexes are DNA-NR when [NR]/[DNA]<0.18 and DNA-3NR when [NR]/[DNA]>0.35, respectively.展开更多
The binding characteristics of neutral red （NR） with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition （SVD） was used to evaluate the number of spectral spec...The binding characteristics of neutral red （NR） with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition （SVD） was used to evaluate the number of spectral species in the drug-DNA binding process, and then the intrinsic binding constant of 1.6 × 10^4 in base pairs and the binding site number of 0.97 were obtained from the Scatchard plot.展开更多
An amperometric hydrogen peroxide biosensor using a nanobiocomposite based on neutral red modified carbon nanotubes and co-immobilized glucose oxidase and horseradish peroxidase is reported. Modification of the nanobi...An amperometric hydrogen peroxide biosensor using a nanobiocomposite based on neutral red modified carbon nanotubes and co-immobilized glucose oxidase and horseradish peroxidase is reported. Modification of the nanobiocomposite electrode with neutral red resulted in a sensitive, low-cost and reliable H_2O_2 sensor. The use of carbon nanotubes, as the conductive part of the composite, facilitated fast electron transfer rates. The biosensor was characterized for the influence of p H, potential and temperature. A remarkable feature of the biosensor is the detection of H_2O_2 at low applied potentials where the noise level and interferences are minimal. The sensor has a fast steady-state measuring time of 10 s with a quick response(2 s). The biosensor showed a linear range from 15 n M to 45 m M of H_2O_2 and a detection limit of 5 n M. Nafion, which is used as a binder, makes the determination free from other electroactive substances. The repeatability, reproducibility,stability and analytical performance of the sensor are very good.展开更多
The interaction between heparin and neutral red was investigated by molecular spectroscopic methods. The change of all spectra suggested that positively charged neutral red had interacted with negatively charged hepar...The interaction between heparin and neutral red was investigated by molecular spectroscopic methods. The change of all spectra suggested that positively charged neutral red had interacted with negatively charged heparin. The study of influence factors indicated that electrostatic force and hydrophobic bond might be involved in the interaction. The total binding number per disaccharide unit and intrinsic binding constant were obtained using Scatchard model.展开更多
Completely weathered phyllite(CWP)soil is a kind of special soil with high swell potential,while red clay is a special soil with high shrinkage.This means that these two kinds of special soils are usually not suitable...Completely weathered phyllite(CWP)soil is a kind of special soil with high swell potential,while red clay is a special soil with high shrinkage.This means that these two kinds of special soils are usually not suitable for direct use as subgrade fill.To reduce the swell index of the CWP soil and the shrinkage of red clay at the same time,it was proposed to blend the CWP soil with red clay to improve their basic characteristics.A series of swell index tests and dry-wet cycle tests of the blended soils have been carried out at varying blending ratios,compaction coefficients and moisture contents.The test results show that the free swell index of the blended soil decreases with the increase of red clay,moisture content and compaction coefficient,respectively.The fissure density of the blended soil first decreases and then increases with the blending ratio,with the lowest being zero when the blending ratio is ranging from 20%to 40%.Through particle microscopic analysis and elemental composition analysis,it is found that the neutralization effect,the dilution effect of swell minerals,and the partition effect of coarse particles play an important role in restraining expansion and shrinkage deformation of the blended soil.Based on the liquid limit requirement of Chinese Railway Design Code(TB 10001-2016),the optimal blending ratio of red clay has been proposed to be 50%.Compared with the CWP soil,the free load swell index of the blended soil is reduced by 45.0%and the fissure density is reduced by 99.3%compared with that of red clay.Therefore,it is feasible to improve the CWP soil by blending it with red clay at an optimal ratio of 50%by using the neutralization effect of the expansion of CWP and shrinkage of red clay.展开更多
[ Objective] The aim of this study was to provide the reference for the artificial breeding of aquatic animals. [ Method] Amoeba discoides and Trichodina were treated by neutral red solution with different concentrati...[ Objective] The aim of this study was to provide the reference for the artificial breeding of aquatic animals. [ Method] Amoeba discoides and Trichodina were treated by neutral red solution with different concentrations to observe the physiological activities of organelles in their death processes. Effects of neutral red solution on the growth of common aquatic animals such as Paramecium caudatum, Euglena viridis and Brachionus plicatilis were analyzed, and the specific lethal mechanism of trace neutral red to A. discoides and Trichodina was also preliminarily studied. [ Re- suit] The neutral red solution at a concentration of 0.5 mg/L damaged the physiological function of contractile vacuole in Trichodina and also had the specific lethal effect on Tdchodina, but it had no effect on the growth and reproduction of non-parasitic protozoa and B. p/icatilis. Neutral red so- lution with certain concentration led to disorder of the physiological functions of A. discoides, such as assimilation and rejection, which was a main factor that caused the death of A. discoides. [ Conclusion] With the advantages such as targeting, safety and easiness to be oxidized and decom- posed, neutral red is an ideal drug for treating the diseases caused by A. discoides and Trichodina, and its suitable concentration is 0. 5 mg/L.展开更多
Neutral Red can be used as an indicator, a stain reagent or a mediator compound in the studies of biological redox systems. No reports dealing with the electrode process of Neutral Red, especially, about its kinetics ...Neutral Red can be used as an indicator, a stain reagent or a mediator compound in the studies of biological redox systems. No reports dealing with the electrode process of Neutral Red, especially, about its kinetics have been published. In this paper we report the determinations of formal reduction potentials, the number of electrons transferred, diffusion coefficient as well as the rate constant of heterogeneous electron transfer展开更多
Poly(neutral red) film modified carbon fibre microelectrodes offer substantial improvement in voltammetric sensitivity and selectivity towards epinephrine (EP). The poly(neutral red) film was electropolymerized by cyc...Poly(neutral red) film modified carbon fibre microelectrodes offer substantial improvement in voltammetric sensitivity and selectivity towards epinephrine (EP). The poly(neutral red) film was electropolymerized by cycling the potential between -0.8 V and +0.8 V. The anodic stripping voltammetric response for EP was found to be dependent on accumulation time and potential. By using a poly(neutral red) film modified carbon fibre microelectrode with a 1 min preconcentration at -1.2 V in biological phosphate buffer solution (pH=7.4), a good linear relationship between the anodic stripping peak currents and EP concentrations was obtained in the range of 2.0×10 -7 ￣ 2.0×10 -5 mol/L. The detection limit was up to 9.0 ×10 -8 mol/L. Moreover, 400 times higher concentrations of vitamin C did not interfere with the measurement of EP. This method was used for determining EP concentrations in epinephrine hydrochloride injection solution with satisfactory results.展开更多
Neutral red is kind of biologic colourant and acidity-basicity indicator. Radiation degradation of neutral red in aqueous solution was done by γ-Ray. The removal rate of chemical oxygen demand, total organic carbon, ...Neutral red is kind of biologic colourant and acidity-basicity indicator. Radiation degradation of neutral red in aqueous solution was done by γ-Ray. The removal rate of chemical oxygen demand, total organic carbon, chroma and the changing of pH value were studied under various conditions. With the increase of absorbed doses, the chemical oxygen demand and chroma decreased conspicuously. The absorbed dose rate has little effect on the degradation of neutral red. When the absorbed doses are the same, the chemical oxygen demand and chroma decreased more obviously with the increase of neutral red concentration. Weak basic condition and proper H2O2 addiation are propitious to removal of chemical oxygen demand of neutral red.展开更多
The fluorescence quenching of inclusion complex of neutral red （NR） and hydroxypropyl-β-cyclodextrin （HP-β-CD） carried by chlorobenzene was investigated. The fluorescence intensity of NR increased due to the for...The fluorescence quenching of inclusion complex of neutral red （NR） and hydroxypropyl-β-cyclodextrin （HP-β-CD） carried by chlorobenzene was investigated. The fluorescence intensity of NR increased due to the formed inclusion complex of HP-β-CD and NR. But the fluorescence intensity of NR-HP-β-CD diminished when chlorobenzene was added, and there was a linear relationship between the fluorescence quenching value of the system （△IF = IF, NR-HP-β-CD - IF, CB-NB-NR-HP-β-CD） and the concentration of chlorobenzene. Based on this, a novel fluorescence quenching method for the determination of chlorobenzene with NR as a fluorescence probe has been developed. Under the optimal conditions, the linear range of calibration curve for the determination of chlorobenzene was 5.0 × 10^-8 - 8.0 × 10^-6 mol/L and the detection limit was 1.0 × 10^-8 mol/L. It has been applied to determination ofchlorobenzene in synthetic waste water samples with satisfactory results.展开更多
基金Supported by the NationalNaturalScience Foundation of China( No. 2 0 175 0 1) and U niversity Key Teachers Programdirected under the Ministry of Education ofP.R.China( No. 2 0 0 0 - 6 5 )
文摘It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.
基金the China PostdoctoralScience Foundation (No. 20070420811)the Edu-cation Department of Henan Province in China (No.200510459016)
文摘Adsorption of Neutral Red (NR) onto peanut husk in aqueous solutions was investigated at 295 K. Experiments were carried out as function of pH, adsorbent dosage, contact time, and initial concentration. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, and Toth isotherm models. The results indicated that the Toth and Langmuir models provided the best correlation of the experimental data. The adsorption capacity of peanut husk for the removal of NR was deter...
文摘The earthworm Metaphire posthuma were used as a model to assess the toxic potential of cadmium incorporated into the soil by environmental or human activities. The retention period of neutral red in the lysosomes of the coelomocytes was used as a biomarker. The viability of harvested coelomocytes by a non_invasive extrusion protocol was 93% with no alteration by the dye during experimentation. The control cells retained dye for 119 and 121 min in normal soil and KCl, respectively, whereas a linear decline in the retention time in the treated earthworm coelomocytes was observed. This illustrated that the presence of cadmium caused damage to the lysosomes of the coelomocytes.
文摘A voltammetric study of the interaction of neutral Red(NR) with DNA at a gold electrode in a phosphate buffer solution is described. After adding DNA in an NR solution, the reduction peak current of NR decreases. The binding mechahisms of NR to DNA in different pH ranges are different. The reduction peak potential of NR in a pH 7.0 phosphate buffer solution in the presence of DNA shifts positively, indicating that the binding of NR to DNA is intercalation action, but at pH=6.0 the reduction peak potential of NR shifts negatively, indicating that the binding of NR to DNA is electrostatic action. The formed complexes are DNA-NR when [NR]/[DNA]<0.18 and DNA-3NR when [NR]/[DNA]>0.35, respectively.
基金The financial support from the National Natural Science Foundation of China （No. 20562009）；the Natural Science Foundation of Jiangxi Province （No. 0620041）；the foundation of the State Key Laboratories of the Chemo/ Biosensing and Chemometrics of Hunan University （No. 2005-22）；the program for Changjiang Scholars and Innovative Research Team in Universities （No. IRT0540）.
文摘The binding characteristics of neutral red （NR） with DNA were investigated by fluorescence spectrometry. Chemometrics approach as singular value decomposition （SVD） was used to evaluate the number of spectral species in the drug-DNA binding process, and then the intrinsic binding constant of 1.6 × 10^4 in base pairs and the binding site number of 0.97 were obtained from the Scatchard plot.
基金Department of Science and Technology(DST)Government of India,for sanctioning financial assistance for executing this programme under Nanomaterials Science and Technology Initiative Programmethe Council of Scientific and Industrial Research(CSIR),Government of India,for granting her fellowship for executing this programme
文摘An amperometric hydrogen peroxide biosensor using a nanobiocomposite based on neutral red modified carbon nanotubes and co-immobilized glucose oxidase and horseradish peroxidase is reported. Modification of the nanobiocomposite electrode with neutral red resulted in a sensitive, low-cost and reliable H_2O_2 sensor. The use of carbon nanotubes, as the conductive part of the composite, facilitated fast electron transfer rates. The biosensor was characterized for the influence of p H, potential and temperature. A remarkable feature of the biosensor is the detection of H_2O_2 at low applied potentials where the noise level and interferences are minimal. The sensor has a fast steady-state measuring time of 10 s with a quick response(2 s). The biosensor showed a linear range from 15 n M to 45 m M of H_2O_2 and a detection limit of 5 n M. Nafion, which is used as a binder, makes the determination free from other electroactive substances. The repeatability, reproducibility,stability and analytical performance of the sensor are very good.
文摘The interaction between heparin and neutral red was investigated by molecular spectroscopic methods. The change of all spectra suggested that positively charged neutral red had interacted with negatively charged heparin. The study of influence factors indicated that electrostatic force and hydrophobic bond might be involved in the interaction. The total binding number per disaccharide unit and intrinsic binding constant were obtained using Scatchard model.
基金This work is supported by the National Natural Science Foundation of China(Grant Nos.52068027,51668018,51768021).
文摘Completely weathered phyllite(CWP)soil is a kind of special soil with high swell potential,while red clay is a special soil with high shrinkage.This means that these two kinds of special soils are usually not suitable for direct use as subgrade fill.To reduce the swell index of the CWP soil and the shrinkage of red clay at the same time,it was proposed to blend the CWP soil with red clay to improve their basic characteristics.A series of swell index tests and dry-wet cycle tests of the blended soils have been carried out at varying blending ratios,compaction coefficients and moisture contents.The test results show that the free swell index of the blended soil decreases with the increase of red clay,moisture content and compaction coefficient,respectively.The fissure density of the blended soil first decreases and then increases with the blending ratio,with the lowest being zero when the blending ratio is ranging from 20%to 40%.Through particle microscopic analysis and elemental composition analysis,it is found that the neutralization effect,the dilution effect of swell minerals,and the partition effect of coarse particles play an important role in restraining expansion and shrinkage deformation of the blended soil.Based on the liquid limit requirement of Chinese Railway Design Code(TB 10001-2016),the optimal blending ratio of red clay has been proposed to be 50%.Compared with the CWP soil,the free load swell index of the blended soil is reduced by 45.0%and the fissure density is reduced by 99.3%compared with that of red clay.Therefore,it is feasible to improve the CWP soil by blending it with red clay at an optimal ratio of 50%by using the neutralization effect of the expansion of CWP and shrinkage of red clay.
基金supported by 863 Project (2005AA601010-05)Student Innovative Experiment Fund of Shenzhen University
文摘[ Objective] The aim of this study was to provide the reference for the artificial breeding of aquatic animals. [ Method] Amoeba discoides and Trichodina were treated by neutral red solution with different concentrations to observe the physiological activities of organelles in their death processes. Effects of neutral red solution on the growth of common aquatic animals such as Paramecium caudatum, Euglena viridis and Brachionus plicatilis were analyzed, and the specific lethal mechanism of trace neutral red to A. discoides and Trichodina was also preliminarily studied. [ Re- suit] The neutral red solution at a concentration of 0.5 mg/L damaged the physiological function of contractile vacuole in Trichodina and also had the specific lethal effect on Tdchodina, but it had no effect on the growth and reproduction of non-parasitic protozoa and B. p/icatilis. Neutral red so- lution with certain concentration led to disorder of the physiological functions of A. discoides, such as assimilation and rejection, which was a main factor that caused the death of A. discoides. [ Conclusion] With the advantages such as targeting, safety and easiness to be oxidized and decom- posed, neutral red is an ideal drug for treating the diseases caused by A. discoides and Trichodina, and its suitable concentration is 0. 5 mg/L.
基金Supported by the Natural Science Foundation of Zhejiang Province
文摘Neutral Red can be used as an indicator, a stain reagent or a mediator compound in the studies of biological redox systems. No reports dealing with the electrode process of Neutral Red, especially, about its kinetics have been published. In this paper we report the determinations of formal reduction potentials, the number of electrons transferred, diffusion coefficient as well as the rate constant of heterogeneous electron transfer
文摘Poly(neutral red) film modified carbon fibre microelectrodes offer substantial improvement in voltammetric sensitivity and selectivity towards epinephrine (EP). The poly(neutral red) film was electropolymerized by cycling the potential between -0.8 V and +0.8 V. The anodic stripping voltammetric response for EP was found to be dependent on accumulation time and potential. By using a poly(neutral red) film modified carbon fibre microelectrode with a 1 min preconcentration at -1.2 V in biological phosphate buffer solution (pH=7.4), a good linear relationship between the anodic stripping peak currents and EP concentrations was obtained in the range of 2.0×10 -7 ￣ 2.0×10 -5 mol/L. The detection limit was up to 9.0 ×10 -8 mol/L. Moreover, 400 times higher concentrations of vitamin C did not interfere with the measurement of EP. This method was used for determining EP concentrations in epinephrine hydrochloride injection solution with satisfactory results.
文摘Neutral red is kind of biologic colourant and acidity-basicity indicator. Radiation degradation of neutral red in aqueous solution was done by γ-Ray. The removal rate of chemical oxygen demand, total organic carbon, chroma and the changing of pH value were studied under various conditions. With the increase of absorbed doses, the chemical oxygen demand and chroma decreased conspicuously. The absorbed dose rate has little effect on the degradation of neutral red. When the absorbed doses are the same, the chemical oxygen demand and chroma decreased more obviously with the increase of neutral red concentration. Weak basic condition and proper H2O2 addiation are propitious to removal of chemical oxygen demand of neutral red.
基金This project was supported by the National Basic Research Program of China （No. 2007CB936602） and the Natural Science Foundation of Shandong Province in China （No. Y2008B20）.
文摘The fluorescence quenching of inclusion complex of neutral red （NR） and hydroxypropyl-β-cyclodextrin （HP-β-CD） carried by chlorobenzene was investigated. The fluorescence intensity of NR increased due to the formed inclusion complex of HP-β-CD and NR. But the fluorescence intensity of NR-HP-β-CD diminished when chlorobenzene was added, and there was a linear relationship between the fluorescence quenching value of the system （△IF = IF, NR-HP-β-CD - IF, CB-NB-NR-HP-β-CD） and the concentration of chlorobenzene. Based on this, a novel fluorescence quenching method for the determination of chlorobenzene with NR as a fluorescence probe has been developed. Under the optimal conditions, the linear range of calibration curve for the determination of chlorobenzene was 5.0 × 10^-8 - 8.0 × 10^-6 mol/L and the detection limit was 1.0 × 10^-8 mol/L. It has been applied to determination ofchlorobenzene in synthetic waste water samples with satisfactory results.
