Yali Han

Shantou University, Shantou, Guangdong Sheng, China

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Publications (12)24.42 Total impact

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    ABSTRACT: A novel free-probe assay of dextrin was established based on the resonance light scattering (RLS) enhancement in aqueous solution due to the self-aggregation of dextrin. The RLS intensity was well proportional to the concentration of dextrin over the wide range 0.2-14microg mL(-1) and a detection limit 0.02microg mL(-1) was obtained in the optimum conditions. The effect factors such as pH, buffer medium, holding time, ionic strength and temperature were studied in detail. Little or no interference was presented in the detection when adding coexisting substances including various metal ions and some saccharine in the solution. The assay proposed owns the advantages of easy operation, rapidity, sensitivity and practicability. Three synthetic samples and three kinds of medicine samples were analyzed with satisfactory results.
    Analytica chimica acta 04/2009; 635(2):202-6. · 4.31 Impact Factor
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    ABSTRACT: A novel resonance light scattering (RLS) decrease method was developed to determine rutin with a simple probe manganese sulfate. At pH 7.5, the strong RLS intensity of manganese sulfate was remarkably decreased by the addition of rutin with the maximum peak located at 389.0 nm. Under the optimum conditions, a good linear relationship between the changes of RLS intensities of manganese sulfate with and without rutin and the concentrations of rutin was obtained over the range of 0.49-24.4 microg ml(-1) and a low detection limit (3sigma) 0.42 microg ml(-1) was achieved in the mean time. Based on this approach, a novel method for quantitative analysis of rutin is proposed in this paper. The method proposed was also applied successfully to the determination of rutin in commercial pharmaceutical preparations of compound rutin tablets and human urine samples. The assay is sensitive, rapid, inexpensive, practical and relatively free from interference generated by coexisting substances.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2008; 71(2):344-9. · 1.98 Impact Factor
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    ABSTRACT: A simple, highly sensitive and dye-less assay for proteins was reported using a resonance light-scattering (RLS) technique based on the enhanced RLS intensity of beta-cyclodextrin (beta-CD)-sodium dodecylsulfate (SDS)-protein system. Under the optimum conditions, the enhanced RLS intensity is in proportion to the concentration of proteins in the range of 0.01 to 2.3 microg ml(-1) for bovine serum albumin (BSA), 0.01 to 2.0 microg ml(-1) for human serum albumin (HSA), 0.015 to 5.0 microg ml(-1) for gamma-globulin (gamma-G), 0.02 to 3.5 microg ml(-1) for egg albumin (EA), 0.02 to 4.0 microg ml(-1) for pepsin (Pep), and 0.02 to 3.6 microg ml(-1) for alpha-chymotrypsin (Chy). Their detection limits (S/N = 3) are 1.1, 1.6, 2.4, 6.7, 5.4 and 4.2 ng ml(-1), respectively. Synthetic samples and human serum samples were determined satisfactorily, and the results were in reasonable agreement with those obtained by a documented spectrophotometric (Bradford) method.
    Analytical Sciences 12/2007; 23(11):1305-10. · 1.57 Impact Factor
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    ABSTRACT: Manganese chloride can form large particles with nucleic acids by electrostatic forces, which results in strong enhancement of resonance light scattering (RLS) signals. Based on this phenomenon, a novel and very simple assay of DNA was established. The work conditions have been investigated including the concentration of probe, the acidity of solution, the effect of ionic strength and the selectivity. In acidic solution, the enhanced RLS intensity at 389.5 nm was proportional to the concentration of nucleic acids in the range 0.05-10.0 microg ml(-1) for both ctDNA and fsDNA and 1.0-10.0 microg ml(-1) for yRNA. The limits of detection (LOD, 3sigma) were 0.17, 0.13 and 0.53 ng ml(-1) for ctDNA, fsDNA and yRNA, respectively. Synthetic samples were determined satisfactorily.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 11/2007; 68(2):263-8. · 1.98 Impact Factor
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    ABSTRACT: A rapid and sensitive method for the determination of proteins is proposed based on the measurements of the enhanced resonance light scattering (RLS) spectroscopy of sodium lauroyl glutamate (SLG). Under the optimum conditions, the interaction between SLG and proteins occurred rapidly, resulting in greatly enhanced RLS intensity with the maximum peak located at 394nm. It was found that the enhanced RLS intensities were in proportion to the concentrations of proteins in the range of 0.01-3.1mugml(-1) depending on the kind of proteins. The detection limits were below 6ngml(-1). Compared with some other methods for the determination of proteins, this method shows high sensitivity, low detection limit and simplicity. This is an inexpensive, simple and fast one-step procedure which requires only measuring the RLS intensities. Human serum samples were determined with satisfactory results.
    Talanta 03/2007; 71(3):1246-51. · 3.50 Impact Factor
  • Analytical Sciences - ANAL SCI. 01/2007; 23(11):1305-1310.
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    ABSTRACT: Based on the interaction between nucleic acids and tetraphenyl porphyrinatoiron chloride (FeTPPCl), a novel method for the determination of nucleic acids at the nanogram level has been developed. Under the optimum conditions, the weak resonance light scattering (RLS) intensity of FeTPPCl was greatly enhanced by nucleic acids and the enhanced RLS intensity was proportional to the concentration of nucleic acids in the range 0.02-2.8 microg/mL for calf thymus DNA, 0.05-3.3 microg/mL for fish sperm DNA and 0.07-4.5 microg/mL for yeast RNA. The detection limits (3sigma) were 2.9 ng/mL for calf thymus DNA, 3.9 ng/mL for fish sperm DNA and 5.2 ng/mL for yeast RNA. Almost no interference could be observed from proteins, nucleosides and most of the metal ions. The proposed method showed good reliability, sensitivity, rapidity and reproducibility when applied to the determination of nucleic acids in synthetic and biochemical samples. The time savings make this method suitable for large routine analyses.
    Luminescence 01/2007; 22(5):493-500. · 1.27 Impact Factor
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    ABSTRACT: A novel assay of DNA at nanogram levels is presented that is based on the measurement of resonance light scattering (RLS) signals in the presence of norfloxacin. The characteristics of RLS spectra, the effective factors and the optimum conditions of the reaction have been investigated. In Britton-Robinson buffer (pH 5.87), norfloxacin has a maximum peak at 405.5 nm and the RLS intensity is greatly enhanced by trace amounts of DNA due to the interaction between norfloxacin and DNA. Mechanistic studies show that the binding of norfloxacin to DNA forms large particles, which result in the significant enhancement of RLS intensity. The enhanced intensity of RLS is proportional to the concentration of DNA in the range from 0.01–2.0 µg mL−1 for yeast DNA, and from 0.02 to 2.3 µg mL−1 for calf thymus DNA. The determination limit (3σ) is 0.7 ng mL−1 for yeast DNA and 1.2 ng mL−1 for calf thymus DNA, respectively. Synthetic samples were determined satisfactorily.
    Microchimica Acta 12/2006; 157(1):107-112. · 3.43 Impact Factor
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    ABSTRACT: The interaction between norfloxacin and calf thymus double-stranded DNA (dsDNA) has been studied by a resonance light scattering (RLS) technique with a common spectrofluorometer. The characteristics of RLS spectra, the effective factors and optimum conditions of the reaction have been investigated. In Britton-Robinson (BR) buffer (pH 5.87), norfloxacin has a maximum peak 405.5 nm and the RLS intensity is remarkably enhanced by trace amount of calf thymus dsDNA due to the interaction between norfloxacin and dsDNA. The binding of norfloxacin to DNA forms large particles, which were characterized by RLS spectrum, scanning electron microscopy (SEM), ultraviolet-visible (UV-vis) spectrum, and fluorescence spectrum. Based on the enhanced RLS intensity, a novel method for sensitive determination of calf thymus dsDNA concentration ranging from 0.02 to 2.3 microg ml(-1) was developed. The determination limit (3 sigma) was 1.2 ng ml(-1). The method is simple, rapid, practical and relatively free from interference generated by coexisting substance, as well as much more sensitive than most of the reported methods. Three synthetic samples of ctDNA were determined with satisfactory results.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 12/2006; 65(3-4):919-24. · 1.98 Impact Factor
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    ABSTRACT: A novel histidine-selective method has been developed for the determination of histidine in aqueous solutions by resonance light scattering (RLS) technique. At pH 8.0, the weak RLS intensity of tetraphenylporphyrin manganese (III) chloride [MnTPPCl] was greatly enhanced by the addition of histidine with the maximum peak located at 483 nm. Under the optimum conditions, it was found that the enhanced RLS intensity was in proportion to the concentration of histidine in the range 7.8 × 10−7–2.4 × 10−5 mol l−1. Low detection limit of 9.2 × 10-8 mol l−1 has been achieved. The histidine concentrations in synthetic samples and real samples were determined with satisfactory results. The sensitivity and selectivity of this method are high enough to permit the determination of trace amounts of histidine without any significant interference from high levels of other components such as common anions and especially, other amino acids.
    Analytica Chimica Acta. 01/2006;
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    ABSTRACT: A novel probe, tetraphenyl porphyrin cobalt chlorine (CoTPPCl), is first applied to determine nucleic acids at the nanogram level based on the measurement of resonance light scattering (RLS) signals, which result from the interaction of CoTPPCl with nucleic acids. Under pH 6.37 conditions, the reaction between CoTPPCl and nucleic acid enhances the weak resonance light scattering (RLS) signal of CoTPPCl, and the enhanced light scattering intensity is proportional to the concentration of nucleic acid. The method is sensitive (3.45 ng/mL for ctDNA), simple (one step and a common fluorimeter), and tolerant of the metal ions and other coexistent substances. The mode of the combination between CoTPPCl and nucleic acids and the reasons for RLS enhancement are clearly clarified. Synthetic samples were determined with satisfactory results.
    Analytical Letters 11/2005; 38(14):2301-2313. · 0.97 Impact Factor
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    ABSTRACT: A new method for the determination of nucleic acids at nanogram per mL level is proposed based on the enhanced resonance light scattering (RLS) signal resulting from the interaction of metalloporphyrins with nucleic acids. Under optimum conditions, the weak RLS signal of metalloporphyrin is enhanced by nucleic acids, and the enhanced RLS intensity is proportional to the concentration of nucleic acids. The detection limits of calf thymus DNA were 3.5ngmL–1, 2.9ngmL–1 and 1.0ngmL–1 for three metalloporphyrins, respectively. Synthetic samples were determined with satisfactory results.
    Microchimica Acta 04/2005; 150(1):35-42. · 3.43 Impact Factor