Sensitive Determination Of Protein By Resonance Rayleigh Scattering

Resonance Rayleigh scattering(RRS) method is a new quantitative analytical technique which was developed in 1990s. In recent years, More attention has been paid to RRS methods, since it is very sensitive and simple. The RRS technique can not only be applied to the determination of biological macromolecules, inorganic ions, pharmaceuticals, and cationic surfactant, but also can be used to the determination of critical micelle concentration and inclusion constant.Protein has many physiological functions. Intracellular proteins that form the main components of protoplasm, which occupy an important place in vivo, are composed of various types of natural life in the most important material. It can be said that without the protein there is no life. Quantitative analysis of protein is often involved in biochemistry and other biological disciplines. It has been an important indicator of clinical testing. Quantitative analysis of protein is also the means of purifying and separation in many biochemicals. Many methods have been developed for protein determination, such as UV absorption spectrophotometry, fluorescence spectrometry, resonance light scattering techniques, etc. Resonance Rayleigh scattering method is a new technology. The main advantage of this technique is sensitive and simple.The main research content and innovation points are as follows:1. In pH 4.2 BR buffer, the binding reaction of methyl blue with proteins enhanced remarkably the resonance Rayleigh scattering (RRS) signal at maximum emission wavelength of 350 nm. It was found that the increase value of RRS intensities were in proportion to the concentrations of IgG under optimum conditions. Based on this, a new method for the determination of IgG using methyl blue as indicator has been developed. The linear ranges of the calibration curves were 0.3-67.2μg/mL, and the detection limit was 0.3μg/mL. The method has the advantages of simplicity and high sensitivity. It has been used to determine IgG in human serum samples. The results were satisfactory.2. CdSe quantum dots were synthesized in aqueous solution by using thioglycolic acid as the stabilizer. The interaction between CdSe quantum dots and human serum albumin was investigated by resonance Rayleigh scattering and second-order scattering spectra. In pH 7.4 Tris buffer solution, the CdSe quantum dots (CdSe-QDs) capped thioglycolic acid (TGA) were labeling with HSA by covalence coupled action, resulting in the great enhancements of intensities of RRS and second-order scattering (SOS), respectively. The enhancements of scattering intensity were directly proportional to the concentration of HSA in a certain range. The detection limits were 0.1μmol/L for RRS method and 0.25μmol/L for SOS. The results showed that the method was simple and sensitive. In addition, the reaction mechanism was discussed. The proposed method was successfully applied to the determination of HSA in uric samples with satisfactory.