Dissertation > Biological Sciences > Biochemistry > Enzymes

A New Method for Thrombin Detection by Using Aptamers and Gold Nanoparticles

Author TianXiang
Tutor ShuangShaoMin;ZhaoQiang
School Shanxi University
Course Analytical Chemistry
Keywords Aptamer Thrombin Magnetic beads Gold nanoparticles
Type Master's thesis
Year 2011
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Chapter 1:Firstly, the significance and methods of protein detection was briefly introduced. Secondly, we introduced the concept and selection of the aptamer, reviewed the advances of the application of aptamer in protein detection. Thirdly, the properties of gold nanoparticles, the application of gold nanoparticles in bioanalysis, the properties of magnetic beads and the application of magnetic beads in separation and analysis were presented. Finally, we illustrated the research background and the innovation of this thesis.Chapter2:Gold nanoparticles were prepared by chemical reduction. Then the gold nanoparticles were characterized by Transmission Electron Microscopy (TEM),and UV-Vis spectroscopy.The aptamer-modified gold nanoparticles were prepared, and the stability of the gold nanoparticles and aptamer-modified gold nanoparticles in different solutions was investigated.Chapter3:Based on magnetic separation and unique optical properties of gold nanoparticles, a colorimetric assay for thrombin was developed by using aptamer-modified gold nanoparticles and magnetic beads conjugated with aptamers to form a sandwich complex of thrombin with gold nanoparticles and magnetic beads. At optimized condition, the assay for thrombin showed a linear range from 2.7 nmol/L to 54.4 nmol/L, and a detection limit of 2.7 nmol/L was reached.Chapter4:The binding of aptamer-modified gold nanoparticles with thrombin led to the aggregation of gold nanopartilces, causing the changed of optical absorption. Thrombin was detected by recording the changes absorption spectra of gold nanoparticles. This method enabled the detection of thrombin in the linear range from 13.6 nmol/L to 272.5 nmol/L, and the detection limit was 13.6 nmol/L.

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