Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Determination of the Binding Parameters between Proteins and Luminol by Chemiluminescence Using Flow Injection Technique  [PDF]
Jie Guo,Donghua Chen,Zhenghua Song
ISRN Analytical Chemistry , 2013, DOI: 10.1155/2013/391053
Abstract: The interaction behavior of bovine serum albumin (BSA), lysozyme (LYS), myoglobin (MB), and catalase (CAT) with luminol, respectively, was first studied by chemiluminescence (CL) using flow injection (FI) technique based on the fact that the studied proteins can enhance the CL intensity of luminol. A FI-CL model of protein-luminol interaction, , was constructed, and the interaction parameters of BSA, LYS, MB, and CAT with luminol were determined accordingly. The binding constants are in the descending order of CAT > MB > LYS > BSA at the level of 105 to 107?L?mol?1, and the number of binding sites of luminol to BSA or LYS is around 2 and to MB or CAT is around 1. The results of thermodynamic parameters ( , , and ) showed that the binding processes of luminol to the four proteins are spontaneous mainly through the hydrophobic force. 1. Introduction Proteins possess many biological functions including binding, catalysis, operating as molecular switches, and serving as structural components of cells and organisms [1, 2] and play an important role in the transportation and deposition of various endogenous and exogenous substances [3, 4]. In recent years, the interaction of protein with small molecules has become a hot spot in the fields of chemistry, biology, and medicine [5–7]. As common model proteins, bovine serum albumin (BSA) [8], lysozyme (LYS) [9], myoglobin (MB) [10], and catalase (CAT) [11] are widely applied to the study of protein-small molecule interaction. Accordingly, many methods have been utilized to investigate this hot topic, such as fluorescence spectroscopy [12], resonance light scattering [13], circular dichroism [14], nuclear magnetic resonance spectroscopy [15], and chemiluminescence (CL) with flow injection (FI) technique [16]. The FI-CL analysis has proven to be a very useful analytical method with advantages of simple apparatus, high sensitivity, wide dynamic ranges, reproducibility, automatability, less reagent consumption [17–19], and so forth. Luminol (5-amino-2, 3-dihydro-1, 4-phthalazinedione) is known to produce CL with the characteristic wavelength of 425?nm under alkaline condition [20, 21], making it widely used around the world as a blood enhancement technique in forensic science. Also this luminescent compound is used clinically in the treatment of alopecia [22], the promotion of blood clotting [23], and wound healing [24]. Due to its high quantum yield, the CL of luminol has been used in many laboratory applications, including environmental field of analyzing trace metals [25, 26], food safety field [27], biological
Ultrasensitive determination for picomolar-level midecamycin in human serum by flow injection chemiluminescence using luminol–BSA system  [PDF]
Hairu Lv,Xijuan Tan,Yun Zhang,Zhenghua Song
Spectroscopy: An International Journal , 2011, DOI: 10.3233/spe-2012-0563
Abstract: An ultrasensitive method for determining picomolar midecamycin (MID) by flow injection (FI) chemiluminescence (CL) was first described based on the inhibitory effect of MID on luminol–BSA reaction. It was found that the CL intensity decrements were linear with the logarithm of MID concentrations in the range of 1.0–5000 pmol · l–1 with a detection limit as low as 0.3 pmol · l–1 (3σ). The relative standard deviation of seven repetitive measurements for 10 pmol · l–1 MID was 3.0%. At a flow rate of 2.0 ml · min–1, the whole analysis procedure including sampling and washing could be finished in 30 s, offering the sample efficiency of 120 h–1. This proposed method was successfully applied to determine MID in human serum samples with the recoveries from 96.0 to 110.0%. The CL mechanism of luminol–BSA–MID reaction was also given.
Flow injection chemiluminescence determination of levofloxacin in medicine and biological fluids based on its enhancing effect on luminol–H2O2 reaction  [PDF]
Xiaodong Shao,Ying Li,Yangqin Liu,Zhenghua Song
Spectroscopy: An International Journal , 2009, DOI: 10.3233/spe-2009-0379
Abstract: Levofloxacin{(–)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid} is a synthetic fluorinated quinolone derivative, having activity against both Gram (+) and Gram (–) bacteria (aerobic and anaerobic) through inhibition of their DNA gyrase. In this paper, a simple flow injection chemiluminescence with luminol–hydrogen peroxide system was described for determining levofloxacin. The chemiluminescence intensity in the presence of levofloxacin was remarkably enhanced compared with that in the absence of it. Under the optimum reaction conditions the chemiluminescence increment produced was proportional to the concentration of levofloxacin in the range of 1.0–700.0 ng ml–1 (R2═0.9992), with a detection limit of 0.3 ng ml–1 (3σ). At the flow rate of 2.0 ml min–1, the whole process including sampling and washing could be completed in 0.5 min offering the sampling efficiency of 120 times h–1 accordingly, and the relative standard deviation (RSD) was less than 3.0% (n═5). The recovery for the levofloxacin samples was from 95.9% to 104.5%. It was satisfactory for the application to determine levofloxacin in pharmaceutical preparations, human urine and serum samples.
Chemiluminescence determination of mezlocillin by the luminol-potassium periodate system
Shi, Wen Bing;Yang, Ji Dong;
Journal of the Brazilian Chemical Society , 2008, DOI: 10.1590/S0103-50532008000600019
Abstract: a new, simple and sensitive method has been proposed for the determination of mezlocillin. it is based on the enhancement of the chemiluminescence (cl) emission generated from the oxidation of luminol in alkaline medium by postassium periodate. the optimization of the experimental and instrumental variables affecting the cl enhancement effect has been carried out using flow-injection system. in the optimum conditions, the method is efficient to determine mezlocillin in the linear range of 0.01-30×10-6 g ml-1 with a detection limit (3σ) of 3.0×10-9 g ml-1 and the relative standard deviation (rsd) is 1.0% for 1.0×10-6 g ml-1 mezlocillin (n=11). it has been successfully applied to the mezlocillin determination in commercial preparations, synthetic samples and biological fluids formulations.
Determination of Nanogram Quantities of Emodin in Pharmaceutical Preparations and Biofluids by Luminol-Myoglobin Chemiluminescence System
Yun Zhang,Xili He,Zhenghua Song
Spectroscopy: An International Journal , 2012, DOI: 10.1155/2012/741053
Abstract: Based on the quenching effect of emodin on the luminol-myoglobin (Mb) reaction, a sensitive method for the determination of nanogram level emodin by flow injection chemiluminescence (FI-CL) is presented for the first time. It was found that the CL intensity from luminol-Mb system could be inhibited in the presence of emodin, and the decrement of CL intensity was linearly proportional to the logarithm of emodin concentration in the range of 0.5–300ng?mL?1 (R = 0.9956) with the detection limit of 0.2ng?mL?1 (3σ). At a flow rate of 2.0mL?min?1, a complete determination of emodin, including sampling and washing, could be accomplished in 0.5 min with the relative standard deviations (RSDs) of less than 3.5% (n = 5). The proposed method was successfully applied to the determination of emodin in pharmaceutical preparations and human serum samples. The possible CL mechanism of luminol-Mb-emodin reaction was explained.
Chemiluminescence detection of permanganate index (CODMn) by a luminol-KMnO4 based reaction
Chemiluminescence detection of permanganate index (CODMn) by a luminol-KMnO4 based reaction

TIAN Jinjun,HU Yonggang,ZHANG Jie,
TIAN Jinjun
,HU Yonggang,ZHANG Jie

环境科学学报(英文版) , 2008,
Abstract: A novel chemiluminescence (CL) system for determination of permanganate index (CODMn) combined with flow injection analysis has been proposed in this study. On the basis of the chemiluminescent reaction of luminol-KMnO4 system, light emission caused by luminol-KMnO4 system was detected by the photomultiplier tube, and its intensity caused by the appearance of KMnO4 after sample digestion was inversely proportional to CODMn. Effects for CODMn determining such as pH, concentrations and interference were investigated in detail. A detection limit of 0.3 mg/L CODMn with a linear range of 0.3-200 mg/L for its theoretical CODMn was obtained under the optimized experimental conditions. The relative standard deviation was 4.3% for 5.0 mg/L CODMn (n = 11). This CL flow system for determining CODMn was simple, rapid, and suitable for automatic analysis. The data obtained by the present method were fairly in good agreement with those obtained by the standard titrimetric method. It has been applied to determine real samples with satisfactory results.
Chemiluminescence Behavior of Luminol-KIO4-Ag Nanoparticles System and Its Analytical Applications  [PDF]
S. F. Li, H. Y. Wang, X. Min, L. Zhang, J. Wang, J. Du, J. Q. Zhang, P. Wei, Z. Q. Wang, H. Zhang, X. W. Wu
Journal of Biomedical Science and Engineering (JBiSE) , 2014, DOI: 10.4236/jbise.2014.76033
Abstract: It was found that silver nanoparticles could strongly enhance the chemiluminescence (CL) of the luminol-KIO4 system in the presence of Co2+. The most intensive CL signals were obtained with silver nanoparticles in diameter of 22 nm. The studies of UV-visible spectra and CL spectra were carried out to explore the possible CL enhancement mechanism. Moreover, the influences of 17 amino acids and 25 organic compounds on the luminol-KIO4-Co2+-Ag NPs CL system were studied by a flow injection procedure, which led to an effective method to detect these compounds.
Utilization of a novel Ag(III)-luminol chemiluminescence system for determination of d-penicillamine in human urine samples
Ma, Li;Fan, Mengdi;Xu, Xiangdong;Kang, Weijun;Shi, Hongmei;
Journal of the Brazilian Chemical Society , 2011, DOI: 10.1590/S0103-50532011000800009
Abstract: a novel sensitive chemiluminescence (cl) system ([ag(hio6)2]5--luminol reaction system), coupled with a flow injection, is introduced for determination of d-penicillamine. the system is based on the enhancement effect of chemiluminescence reaction by penicillamine in alkaline medium. under the optimum conditions, the cl intensity is proportional to the concentrations of d-penicillamine with a good linearity. the linear range covers 1.5-150 ng ml-1 and the limit of detection of the method is 0.8 ng ml-1. the relative standard deviation is 0.23% for 11 repeated measurements of 0.06 μg ml-1 d-penicillamine. the method has been successfully applied to the determinations of d-penicillamine in pharmaceutical preparations and urine samples, giving rise to satisfactory results. based on the chemiluminescent spectra and free radical trapping experiment performed in this work, a possible reaction mechanism for this reaction system is suggested.
Enhancement of chemiluminescence of Luminol-EDTA system by CuFe2O4 nanoparticals and its application

- , 2017, DOI: 10.11835/j.issn.1000-582X.2017.04.008
Abstract: 基于CuFe2O4纳米粒子能显著增强Luminol-EDTA体系的发光,首次建立了Luminol-EDTA-CuFe2O4 NPs化学发光新体系。紫外吸收光谱和化学发光光谱表明纳米CuFe2O4注入Luminol-EDTA体系后,未生成新发光物质,结合纳米CuFe2O4的特性,提出了CuFe2O4 NPs参与Luminol-EDTA体系可能的发光机理。研究发现芦丁能抑制Luminol-EDTA-CuFe2O4 NPs体系的化学发光,结合流动注射技术,将此化学发光体系应用于芦丁片中芦丁含量的测定。在优化实验条件下,芦丁浓度在2×10-8~2×10-5 mol/L范围内芦丁浓度的对数和相对化学发光值呈线性,芦丁浓度检出限(LOD)为1.21×10-9 mol/L。将本方法应用于芦丁片中的芦丁含量测定,回收率为97%~102%,RSD为2.54%(c=1×10-7mol/L,n=11)。
A new chemiluminescence system of Luminol-EDTA-CuFe2O4 NPs was firstly developed based on the fact that CuFe2O4 nanoparticals (NPs) could significantly enhance the chemiluminescence (CL) intensity of the Luminol-EDTA system. The UV-Vis spectra and the chemiluminescence spectra suggested that no new luminophor formed after the introducing of CuFe2O4 NPs in the Luminol-EDTA system. The possible mechanism of CuFe2O4 NPs participated in Luminol-EDTA system was proposed by combining with the property of CuFe2O4 NPs. Additionally, it was found that rutin could inhibit the chemiluminescence of the proposed Luminol-EDTA-CuFe2O4 NPs system. Combined with flow injection, the system was applied to the determination of rutin in rutin tablets. Under the optimal conditions, the relationship between the relative CL intensity and the logarithm of concentration of rutin was linear when the concentration of ratin ranged from 2×10-8 mol/L to 2×10-5 mol/L with the detection limit of 1.21×10-9 mol/L. The recommended method has been successfully applied to the determination of rutin tablets and the recovery was between 97%-102% and RSD (c=1×10-7mol/L, n=11) was 2.54%
Magnolia officinalis Extract Antioxidant Activity Analysis Based on Microfluidic CL Chip

张涛, 张潇丹, 王蓉, 张贝, 吕君江, 徐溢
Journal of Sensor Technology and Application (JSTA) , 2016, DOI: 10.12677/JSTA.2016.41003
Abstract: 设计并制作了一种集成有四个重复结构单元的微流控化学发光(chemiluminescence, CL)芯片,以实现中药材厚朴提取物的分子水平的抗氧化活性分析。芯片结构单元包含蛇形通道、高效环形混合通道和椭圆形检测区。微流控CL芯片系统一次可完成单一样本多浓度的检测。采用luminol-H2O2-Cu2+化学发光体系对厚朴酚、和厚朴酚标品进行CL测试以验证该芯片可靠性,并得出最佳测试条件为:Luninol浓度为0.50 mmol?L?1,H2O2浓度为1.00 mmol?L?1,Cu2+浓度为0.50 mmol?L?1,流速10.0 μL?min?1。进而对厚朴药材五种醇提物进行CL测试,结果表明,五种提取物对H2O2均有一定的清除作用,且1.00 g?ml?1的五种提取物的当量抗氧化活性强弱顺序为:80%乙醇提取物 > 60%乙醇提取物 > 40%乙醇提取物 > 20%乙醇提取物 > 水提取物。
An integrated microfluidic chip with four repeating structural units was designed and fabricated to achieve molecular level of Magnolia medicines extracts antioxidant activity analysis. Chip structure unit includes a serpentine channel, efficient mixing channel and an oval ring detection zone. The Microfluidic chemiluminescence chip system could successfully complete synchronous detection of single sample with different concentration. Using luminol-H2O2-Cu2+chemiluminescence system for Magnolol, Honokiol CL-standard products were tested to verify the reliability of the chip, and optimum test conditions are: luminol concentration is 0.50 mmol?L?1, the H2O2 concentration is 1.00 mmol?L?1, Cu2+ concentration is 0.50 mmol?L?1 and the flow rate is 10.0 μL?min?1. Furthermore Magnolia officinalis extracts from five alcohol antioxidant activity test results showed that the five extracts antioxidant activity, which was extracted under different condition from 1.00 g?mL?1 Magnolia officinalis, has a certain effect to remove H2O2, and the order of antioxidant activity strength was: 80% ethanol extract > 60% ethanol extract > 40% ethanol extract> 20% ethanol extract> aqueous extract.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.