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Abstract: A novel method for determination of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) in an extract from mung bean sprouts using high performance liquid chromatography (HPLC) with chemiluminescence (CL) detection is described. The method is based on the CL reaction of auxin (indole-3-acetic acid and indole-3-butyric acid) with acidic potassium permanganate (KMnO4) and tris(2,2′-bipyridyl)ruthenium(II), which was immobilized on the cationic ion-exchange resin. The chromatographic separation was performed on a Nucleosil RP-C18 column (i.d.: 250mm×4.6mm, particle size: 5μm, pore size: 100) with an isocratic mobile phase consisting of methanol–water–acetic acid (45:55:1, v/v/v). At a flow rate of 1.0mLmin−1, the total run time was 20min. Under the optimal conditions, the linear ranges were 5.0×10−8 to 5.0×10−6 gmL−1 and 5.0×10−7 to 1.0×10−5 gmL−1 for IAA and IBA, respectively. The detection limits were 2.0×10−8 gmL−1 and 2.0×10−7 gmL−1 for IAA and IBA, respectively. The relative standard deviation (RSD) of intra-day were 3.1% and 2.3% (n =11) for 2×10−6 gmL−1 IAA and 2×10−6 gmL−1 IBA; The relative standard deviations of inter-day precision were 6.9% and 4.9% for 2×10−6 gmL−1 IAA and 2×10−6 gmL−1 IBA. The proposed method had been successfully applied to the determination of auxin in mung bean sprouts. [Copyright &y& Elsevier]

Abstract: This paper developed optical fiber sensor based on molecular imprinted polymer as artificial recognition element for the determination of 6-mercaptopurine (6-MP) in human serum. This approach displayed high sensitivity by oxidizing 6-MP to a strong fluorescent compound with H2O2 in the alkaline media. It offered a relatively nice selectivity for 6-MP detection by molecular imprinted polymer''s recognition. The relative standard deviation (R.S.D.) was 5% for a same sensor (n =5) when 6-MP concentration was 1.0×10−7 gmL−1 in serum. The developed method was satisfactorily applied to the determination of 6-MP in human serum without any necessity for sample treatment or time-consuming extraction steps prior to the analysis. [Copyright &y& Elsevier]

Abstract: A novel fluoroimmunoassay (FIA) method was developed for the determination of tumor necrosis factor-α (TNF-α) in this study. The proposed method has the advantage of showing the specificity of immunoassays and sensitivity of fluorescent nanoparticles label technology. With the well-established inverse microemulsion polymerisation process, the tris(2′,2-bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy)-doped fluorescent silica nanoparticles (RuDFSNs) were prepared. Then a RuDFSNs-labeled anti-TNF-α monoclonal antibody was prepared and used for FIA of TNF-α in human serum samples with a sandwich FIA by using the low fluorescent 96-well transparent microtiter plates. The assay response was linear from 1.0 to about 250.0pg/mL with a detection limit of 0.1pg/mL for TNF-α. The intra- and inter-assay precision are 4.9%, 4.4%, 4.6%; 6.1%, 5.9%, 5.3% for five parallel measurements of 2.0, 20.0, 200.0pg/mL TNF-α respectively, and the recoveries are in the range of 96–104% for human serum sample measurements by standard-addition method. We also explored the application of fluorescence microscopy imaging in the study of the FIA for TNF-α with the fluorescent nanoparticle labels. The results demonstrate that the method offers potential advantages of sensitivity, simplicity and good reproducibility for the determination of TNF-α, and is applicable to the determination of TNF-α in serum samples and being capable of fluorescence microscopy imaging for the determination of TNF-α. [Copyright &y& Elsevier]

Abstract: The paper presented a novel chemiluminescence (CL) immunoassay method, which combines the advantages of traditional enzyme-linked immunosorbent assays (ELISA) and bis (2,4,6-trichlorophenyl) oxalate (TCPO)–hydrogen peroxide CL detection system. A fluorescent product 2,3-diaminophenazine (DAPN) was produced by reaction between o-phenylenediamine (OPDA, 1,2-diaminobenzene) and H2O2 catalyzed by horseradish peroxidase (HRP). DAPN was excited by the reactive intermediate of TCPO–H2O2 chemiluminescent reaction, and led to CL. The dependence of the CL intensity on the concentrations of antigen was studied. As analytical application, the proposed method was used for determination of recombinant human interleukin 6 (rHu IL-6) and β-human chorionic gonadotropin (β-HCG). Under the selected experimental conditions, a linear relationship was obtained between the CL intensity and the concentration of rHu IL-6 in the range of 4.0–625.0pg/ml, and β-HCG in the range of 12.5–400.0mIU/ml. The detection limits were 0.5pg/ml for rHu IL-6 and 3mIU/ml for β-HCG with relative standard deviation of 2.3 for 78.0pg/ml rHu IL-6, and 3.9 for 50.0mIU/ml β-HCG. This method has been applied to the determination of rHu IL-6 in human serum and β-HCG in urine with satisfactory results. [Copyright &y& Elsevier]

A novel chemiluminescence (CL) system for automatic determination of chemical oxygen demand (COD) combined with flow injection analysis is proposed in this paper. In this system, potassium permanganate is reduced to Mn2+ which is first adsorbed on a strongly acid cation-exchange resin mini-column to be concentrated during chemical oxidation of the organic compounds at room temperature, while the excessive MnO4− passes through the mini-column to be waste, then the concentrated Mn2+ is eluted reversely and measured by the luminol–H2O2 CL system. The calibration graph is linear in the range of 4–4000 mg l−1 and the detection limit is 2 mg l−1. A complete analysis could be performed in 1.5 min including washing and sampling, giving a throughout of about 40 h−1. The relative standard deviation was 4.4% for 10 mg l−1 COD (n=11), 4.8% for 100 mg l−1 COD (n=11). This CL flow system for determination of COD is very simple, rapid and suitable for automatic and continuous analysis. The presented system has been applied successfully to the determination of COD of water samples. [Copyright &y& Elsevier]

A novel chemiluminescence (CL) detection scheme has been developed for detecting underivatized amino acids following capillary electrophoresis (CE) separation. This detection was based on the inhibitory effect of amino acids on the CL reaction between luminol and BrO− in alkaline aqueous solution. Detection of amino acids was accomplished with a borate-based background electrolyte at pH 9.2. The luminol was used as a component of the separation carrier electrolyte. Parameters affecting CE–CL separation and detection, such as the pH value, the concentration of electrolyte and CL reagent on the resolution were optimized. The relative standard deviation for the analysis of amino acids was less than 1.5% for the migration time and 4% for the peak height. The mass limits of detection were from 7 to 144 fmol for the 7 amino acids. This method has been applied of 7 amino acids in amino acid injection. [Copyright &y& Elsevier]

A chemiluminescence (CL) biosensor on a chip coupled to microfluidic system is described in this paper. The CL biosensor measured 25×45×5 mm in dimension, was readily produced in analytical laboratory. Glucose oxidase (GOD) was immobilized onto controlled-pore glass (CPG) via glutaraldehyde activation and packed into a reservoir. The analytical reagents, including luminol and ferricyanide, were electrostatically co-immobilized on an anion-exchange resin. The most characteristic of the biosensor was to introduce the air as the carrier flow in stead of the common solution carrier for the first. The glucose was sensed by the CL reaction between hydrogen peroxide produced from the enzymatic reaction and CL reagents, which were released from the anion-exchange resin. The proposed method has been successfully applied to the determination of glucose in human serum. The linear range of the glucose concentration was 1.1–110 mM and the detection limit was 0.1 mM (3σ). [Copyright &y& Elsevier]

A novel chemiluminscence (CL) flow-through sensor for ofloxacin is described. It was based on the sensitizing effect of ofloxacin on the CL oxidation of sulfite by PbO2 in H2SO4 media. By a very simply means, the solid-phase PbO2 was immobilized inside of the CL flow cell as CL oxidant. The column of solid PbO2 could be reused about 400 times during a period of 50 h. The calibration graph is linear in the range 0.2–10 μg ml−1 with a detection limit of 7.8×10−8 g ml−1 (S/N=3). This method has been successfully applied to determine ofloxacin in pharmaceutical preparation. [Copyright &y& Elsevier]

A novel fluoroimmunoassay (FIA) method was developed for the determination of tumor necrosis factor-alpha (TNF-alpha) in this study. The proposed method has the advantage of showing the specificity of immunoassays and sensitivity of fluorescent nanoparticles label technology. With the well-established inverse microemulsion polymerisation process, the tris(2',2-bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy)-doped fluorescent silica nanoparticles (RuDFSNs) were prepared. Then a RuDFSNs-labeled anti-TNF-alpha monoclonal antibody was prepared and used for FIA of TNF-alpha in human serum samples with a sandwich FIA by using the low fluorescent 96-well transparent microtiter plates. The assay response was linear from 1.0 to about 250.0pg/mL with a detection limit of 0.1pg/mL for TNF-alpha. The intra- and inter-assay precision are 4.9%, 4.4%, 4.6%; 6.1%, 5.9%, 5.3% for five parallel measurements of 2.0, 20.0, 200.0pg/mL TNF-alpha respectively, and the recoveries are in the range of 96-104% for human serum sample measurements by standard-addition method. We also explored the application of fluorescence microscopy imaging in the study of the FIA for TNF-alpha with the fluorescent nanoparticle labels. The results demonstrate that the method offers potential advantages of sensitivity, simplicity and good reproducibility for the determination of TNF-alpha, and is applicable to the determination of TNF-alpha in serum samples and being capable of fluorescence microscopy imaging for the determination of TNF-alpha.

A novel chemiluminescence (CL) detection scheme has been developed for detecting underivatized amino acids following capillary electrophoresis (CE) separation. This detection was based on the inhibitory effect of amino acids on the CL reaction between luminol and BrO(-) in alkaline aqueous solution. Detection of amino acids was accomplished with a borate-based background electrolyte at pH 9.2. The luminol was used as a component of the separation carrier electrolyte. Parameters affecting CE-CL separation and detection, such as the pH value, the concentration of electrolyte and CL reagent on the resolution were optimized. The relative standard deviation for the analysis of amino acids was less than 1.5% for the migration time and 4% for the peak height. The mass limits of detection were from 7 to 144 fmol for the 7 amino acids. This method has been applied of 7 amino acids in amino acid injection.

A novel chemiluminscence (CL) flow-through sensor for ofloxacin is described. It was based on the sensitizing effect of ofloxacin on the CL oxidation of sulfite by PbO(2) in H(2)SO(4) media. By a very simply means, the solid-phase PbO(2) was immobilized inside of the CL flow cell as CL oxidant. The column of solid PbO(2) could be reused about 400 times during a period of 50 h. The calibration graph is linear in the range 0.2-10 mug ml(-1) with a detection limit of 7.8x10(-8) g ml(-1) (S/N=3). This method has been successfully applied to determine ofloxacin in pharmaceutical preparation.