Dissertation > Excellent graduate degree dissertation topics show

Detections of Mercury(Ⅱ) and Lead(Ⅱ) Ions Based on Nucleic Acid Probes

Author: GaoXiaoXia
Tutor: YangRongHua
School: Hunan University
Course: Analytical Chemistry
Keywords: Mercury ions Lead ions Functional nucleic acids Fluorescence Colorimetry
CLC: X830.2
Type: Master's thesis
Year: 2011
Downloads: 230
Quote: 0
Read: Download Dissertation

Abstract


Heavy metal ions are one kind of main pollutants in the environment, which have caused great threat to human living conditions. Heavy metal ions in the environment are difficult to degrade, which can be accumulated into the human body through the food chain, leading a serious threat to people’s health and life. Therefore, it is of great significance to establish a simple, fast, sensitive method to detect them as to the control of environmental pollution and the protection of human health. Probes based on nucleic acids （DNA probe） with advantages of real-time, quick, stable, selective and visual inspection make its broad space to used in pharmaceutical, environment, food and metal areas. In this research paper, we construct three DNA probes to detect mercury and lead ions, the details are described as follows:（1） A probe based on the thymine-Hg2+-thymine (T-Hg2+-T) coordination chemistry and the inclusion interaction ofγ-cyclodextrin was developed. A bis-pyrene-labeled thymine-rich DNA strand was used as the detection probe. In the presence of Hg2+, the stem-close-shaped DNA strand can be formed under the cooperation ofγ-cyclodextrin and predominantly emit the excimer fluorescence ideally. With the optimum conditions, the system exhibits a dynamic response range for Hg2+ from 0.5 to 3μM with a detection limit of 0.3μM. This strategy afforded exquisite selectivity for Hg2+ against other environmentally related metal ions. At the same time, pyrene excimer has a longer fluorescence lifetime, combined with lifetime-based measurements, the probe hold potential applied in complex biological samples.（2） A probe based on label-free DNAzyme colorimetric molecular switch for detection of Pb2+ was developed. The system including DNAzyme and guanine（G）-rich DNA strand. In the presence of Pb2+, the substrate strands was released to solution and formed G-quadruplex, resulting absorbance change to detect Pb2+. The system exhibits a dynamic response range for Pb2+ from 5 to 100 nM with a detection limit of 3 nM. In addition, the selectivity of the sensor for Pb2+ against other environmentally related metal ions is outstanding.（3） A probe based on label-free DNAzyme ?uorescing molecular switch for detection of Pb2+ was developed. In the presence of Pb2+, DNAzyme was fracture, and the obvious fluorescent change of the Sybr Green I （SG）, after binding to double strand or single strand DNA was observed. The system exhibits a dynamic response range for Pb2+ from 1 to 8μM with a detection limit of 0.6μM. this strategy afforded exquisite selectivity for Pb2+ against other environmentally related metal ions.

Related Dissertations

  1. Syntheses, Structures and Properties of Metal-organic Frameworks Based on Dicarboxylate Ligands,O621.13
  2. Cloning and Characterization of Five Zinc-finger Proteins (ZFPs) Related with Stresses in Cotton (Gossypium Hirsutum L.),S562
  3. Preparation and Luminescence Properties of Carbazole and Anthracene Derivatives,O626
  4. Establish the Detection Methods of miRNA in Tissue/Serum of NSCLC by Real-time Fluorescence Quantitative PCR and xMAP Bead-based Suspension Array and Their Application Research,R734.2
  5. Syntheses, Structures and Properties of Metal-organic Coordination Polymers Based on Long-Chain Aromaticmulticarboxylate,O631.3
  6. Detection Technology of MicroRNA-21 for Non-small Cell Lung Cancer,R734.2
  7. Conversion luminescence of rare earth fluoride nanocrystals Preparation and Application,TB383.1
  8. YAG: Ce 3 Preparation and luminescent properties of phosphor,TQ422
  9. Brucine , strychnine and human serum albumin between the role of non-covalent binding,R969
  10. Wireless sensor networks based on electrical substation temperature monitoring technology research,TM63
  11. Impact aerobic granular sludge formation and structural stability of the key components of extracellular polymer research,X703
  12. Copper and chromium on the mechanism of toxicity and chlorella detoxification method,X173
  13. Research on the Detection Methods and Technology of Microfluidic Chip Based on Image Processing,TP391.41
  14. A Multifunctional Folate Receptor Targeted, Paramagnetic and Fluorescent Liposome,R943
  15. Target-To-Background Separation Based Spectral Unmixing for In-Vivo Fluorescence Imaging with Sparse Channels,TP391.41
  16. The Construction of Streptavidin-Fluorescence Phycobiliprotein(SA-CpcB-PEB) and Its Application to Fluorescence Immunoassay,O657.3
  17. Design of Nano-scale Precision Position Servo-controller in Fluorescence Microscopy Imaging System,R318.6
  18. Comparative Analysis of mRNA Expression of Tumor Necrosis Factor Like Ligand 1A and Indoleamine-2, 3-dioxygenase in the Peripheral Blood Monocytes of the Patients with Rheumatoid Arthritis,R593.22
  19. Synthesis and Properties of Cyclotriphosphazene Derivatives with Tetrazole and Oxadiazole Groups,O627.51
  20. Fluorescence Properties of 2-Pyridinecarbaldehyde-p-phenylenedi Hydrazone and Its Application to Iron and EDTA Determination,O657.3
  21. Optical Properties of Two Coupled Cooper-pair Boxes Interacting with Two Modes Field,O431.2

CLC: > Environmental science, safety science > Environmental Quality Assessment and Environmental Monitoring > Environmental monitoring > General issues > Monitoring and analysis methods
© 2012 www.DissertationTopic.Net  Mobile