Optical Thermophoresis for the Manipulation and Detection of Biomolecules

  • 遊 麗仙

Student thesis: Master's Thesis


Thermophoresis is a phenomenon about the migration of particles in a temperature gradient Particles with positive Soret effect move to cold regions in a thermal gradient In this study we investigate how to use thermophoresis to concentrate and quantify biomolecules Near infrared laser (1064 nm) is used to provide a temperature gradient to generate thermophoretic effects in the buffer solution in which polyethylene glycol (PEG) is added to make the direction of the thermophoretic motion to be toward the heated region This study developed a way to make the thermophoretic behavior of fluorescent molecule change with the concentration of the target molecules significantly so that we can more accurately quantify target molecules by measuring the distribution of fluorescence intensity between heated area and non-heated area DNA functionalized gold nanoparticles (AuNPs) and aptamer are used as probe to detect molecules This study developed two different detection mechanisms one is applicable to nucleic acid; the other is applicable to proteins or other small molecules The results show that the intensity difference between the heated region and the surrounding region is higher when the concentration of the target DNA increases but protein decreases Under our experimental condition the DNA detection is most sensitive when the concentration of the target DNA is between 2 nM and 20 nM and protein detection is between 6 nM and 300 nM In conclusion we have successfully utilized thermophoresis to accumulate and quantify biomolecules We accumulate the molecules by simply using laser irradiation and determine the concentration of the target molecules based on the image captured after thermophoretic accumulation
Date of Award2014 Sep 2
Original languageEnglish
SupervisorWen-Tai Chiu (Supervisor)

Cite this