Dissertation > Medicine, health > Basic Medical > Medical science in general > Biomedical Engineering > General issues > Biomaterial

The Interaction between Hemoglobin and Ag、CdS and CdSe Nanoparticles and Its Biological Application

Author LiuXinYan
Tutor LiangHong;ShenXingCan
School Guangxi Normal University
Course Inorganic Chemistry
Keywords Silver nanoparticles CdS quantum dots CdSe quantum dots Hemoglobin Binding constants Interaction Fluorescence Quenching
CLC R318.08
Type Master's thesis
Year 2006
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Chapter 1: This chapter reviews the nanomaterials used in biotechnology research progress. Including the application of nanomaterials in the clinical diagnosis and disease detection; nano-probes to identify nucleic acid sequence; directing and targeted drug release. The study of the interaction of nanoparticles with biomolecules progress and hemoglobin. Our group of research in recent years and the significance of the topic of the thesis. Chapter II: the use of UV - visible absorption spectroscopy (UV-vis), fluorescence spectroscopy, synchronous fluorescence spectroscopy, circular dichroism (CD) spectroscopy and Fourier transform infrared spectroscopy (FT-IR) and other means, bovine hemoglobin (Bovine Hemoglobin BHb) and the interaction of the silver nanoparticles. The results show that the BHb can be adsorbed on the surface of the silver nanoparticles, so that at 415 nm characteristic plasmon resonance absorption peak intensity decreased peak red shift. With silver nano-particles of increasing concentration of BHb molecule Soret band absorption continued to decrease, the silver nano-particles may be part of the heme group desorbed from their key cavity. Stern-Volmer equation analysis, the silver nanoparticles static quenching BHb the intrinsic fluorescence. By UV-vis and fluorescence spectra, calculated BHb with silver nanoparticles binding constant of the order of magnitude of 109 to 1010. Synchronous fluorescence spectra blue shift of the silver nanoparticles disturbance BHb intramolecular tyrosine and tryptophan residues in which the micro-environment, so embedded in the hydrophobic cavity. Fitting calculation of the far-UV CD data found, the silver nanoparticles minor secondary structural changes induced BHb, α-helix content decreased. FT-IR spectrum results suggest that of BHb the sulfur of the cysteine ??residue, the carboxyl oxygen, an amide, and the amino acid residues of the nitrogen atom with silver nano-particles may have a surface bond cooperation with. Chapter 3: The use of UV - visible absorption spectroscopy (UV-vis), fluorescence spectroscopy, synchronous fluorescence spectroscopy and Fourier transform infrared spectroscopy (FT-IR), research CdS quantum dots hemoglobin structure and conformation under physiological conditions . The research results show that the CdS quantum dots can be induced part of the heme group spun off from the key chamber. Hemoglobin intrinsic fluorescence quenching of the addition of CdS quantum dots, according to the Stern-Volmer equation, the quenching mechanism in the low concentration of quantum dots for static quenching, the higher concentration of dynamic quenching. The magnitude of the binding constant obtained by UV-Vis and fluorescence data CdS quantum dots and hemoglobin are 106. By analyzing the thermodynamic parameters? H0,? S0? G0 learned that consist primarily of static electricity and hydrophobic interaction in the process of bonding. FT-IR spectrum results suggest, CdS quantum dots only slightly changes the secondary structure of the hemoglobin α? Spiral remains in the secondary structure of a main component, presumably binding sites mainly carboxyl oxygen in the hemoglobin molecule, an amide and an amino acid the nitrogen atom in the residue. Chapter IV: In this paper, CdSe quantum dot fluorescence enhancement phenomenon to establish a new method for a detection of trace amounts of human hemoglobin, and to explore the mechanism of enhanced fluorescence of CdSe quantum dots. Optimal test conditions, the hemoglobin concentration in of 0.375 ~~ 105 ng · ml? 1 within CdSe quantum dot fluorescence enhancement and hemoglobin concentration showed a good linear relationship. The detection limit is 0.18 ng · ml? 30 ng · ml? 1 hemoglobin, the relative standard deviation of the method was 0.41% (measured 9 times). The law of the strong anti-interference, measured in blood hemoglobin with satisfactory results.

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