| Resonance light scattering (RLS) technique is a new molecular spectrumanalytical method. With the distinct advantages of convenience, sensitivity andselectivity, RLS is increasingly gaining more and more attention among theinternational and internal analytical and biochemical researchers. During the ten plusyears, especially with the development of the molecular recognition functional RLSprobes, the high-sensitivity RLS technique is developed even more quickly and playan important role in the biochemical analysis process, demonstrating enormousapplication potential. To further study and develop high-sensitivity, high-selectivity,simple and convenient RLS new determination method and system naturally becomesa very important study subject.In this dissertation, with several spectral techniques, scanning electronmicroscopy (SEM) and Atomic force microscopy (AFM), we have established 8 newRLS methods for the determination of amino acid and biomacromolecules (DNA andproteins). The main content can be described as follows:RLS probes including etraphenyl porphyrinatoiron chloride (FeTPPCl),tetraphenylporphyrin manganese chloride (MnTPPCl), tetraphenylporphyrin cobaltchloride (CoTPPCl) and were used for the determination of histidine. The systems ofFeTPPCl-histidine, MnTPPCl-histidine and CoTPPCl-histidine were firstlyinvestigated by RLS spectroscopy, and we also studied the effect of the factors and theoptimum reaction conditions. Under the weak basic condition, with Britton-Robinson(B-R) as a buffer, great RLS enhancement was produced when FeTPPCl, MnTPPClor CoTPPCl reacted with histidine, and the enhanced RLS intensity was in proportionto the concentration of histidine. Therefore, 3 selective and sensitive methods for thedetermination of histidine were developed. Different metallic monoporphyrins havedifferent sensitivities for the determination of histidine, and we have also discussed the differences among them. When FeTPPC1, MnTPPC1 and CoTPPC1 are used forthe determination of histidine, the linear ranges of histidine are as follows:1.8×10-7-2.7×10-5 mol/L, 7.8×10-7-2.4×10-5 mol/L and 5.1×10-7-1.4×10-5mol/L, withthe detection limits of 1.4×10-7 mol/L, 9.2×10-8 mol/L and 4.3×10-8 mol/Lrespectively. Based on the previous study of the interactions between histidine and the3 metallic monoporphyrins respectively, we studied the interaction between histidineand metallic bisporphyrin (FeTPP)2O. The difference of reaction mechanism betweenbisporphyrin and metallic monoporphyrin was discussed, and an even more sensitivemethod for the determination of histidine was proposed. The linear range is4.0×10-7-1.9×10-5 mol/L and the detection limit is 3.6×10-8 mol/L. The experimentalresults showed that metallic bisporphyrins are more sensitive RLS probes thanmetallic monoporphyrins for the determination of histidine.RLS probes including amino acid-type surfactants sodium lauroyl glutamate(SLG), sodium lauroyl sarcosinate (SLS), and seaweed polysaccharide sodiumalginate (SA) were used for the determination of proteins. Under the optimumconditions, the interaction between SLG and protein occurred rapidly, resulting ingreatly enhanced RLS intensity. It was found that the enhanced RLS intensities werein proportion to the concentration of proteins in the range of 0.01-2.7μ/mL for BSA,0.04-2.2μg/mL for HSA, 0.08-1.7μg/mL forγ-G, 0.08-3.1μg/mL for lysozyme,0.01-1.3μg/mL for hemoglobin, with the detection limits of 1.4 ng/mL for BSA, 1.7ng/mL for HSA, 2.8 ng/mL forγ-G, 4.6 ng/mL for lysozyme and 5.8 ng/mL forhemoglobin respectively. The experiment results show that electrostatic attraction wasthe one of the most strong drive forces for the interaction between SLG and protein.However, hydrophobic interaction and electrostatic attraction all played importantroles in the interaction between SLS and protein. If SLS was used for thedetermination of proteins, the linear ranges are 0.0025-1.2μg/mL for BSA,0.0075-0.9μg/mL for HSA, 0.02-1.4μg/mL forγ-G; 0.04-2.1μg/mL for lysozyme,0.01-0.6μg/mL for hemoglobin and 0.02-0.8μtg/mL for egg albumin, with thedetection limits of 1.3 ng/mL for BSA, 0.8 ng/mL for HSA, 2.7 ng/mL forγ-G, 3.2ng/mL for lysozyme, 4.3 ng/mL for hemoglobin and 3.9 ng/mL for egg albumin respectively. In addition, The RLS spectrum of SA-protein system was firstly studiedand the results showed that the interaction between SA and protein could producegreat enhanced RLS intensity, further more, the enhanced RLS intensities were inproportion to the concentration of proteins in the range of 0.05-9.5μg/mL for BSAand 0.01-6.0μg/mL for HSA, and the detection limits are 1.8 ng/mL for BSA and 1.5ng/mL for HSA respectively. The use of SA as a RLS probe for the determination ofprotein has not yet been reported. Therefore, 3 new methods for the determination ofproteins were established.Gemini zwitterionic surfactant phosphodiesters quaternary ammonium salt(PQAS) was firstly used for the determination of nucleic acids. PQAS is a kind ofGemini zwitterionic surfactants. Compared with single-chain surfactants, Geminisurfactants have various shapes and characteristics of ordered molecular aggregators,and possess their unique characters. The determination of nucleic acids with PQAShas not yet been reported. It was found that PQAS reacted quickly with nucleic acids,resulting in strong RLS enhancement. And the enhanced RLS intensities wereproportional to the concentration of nucleic acids in the range of 0.01-9.0μg/mL forctDNA and 0.04-7.5μg/mL for fsDNA, with the detection limits of 1.4 ng/mL forctDNA and 2.5 ng/mL for fsDNA respectively.
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