Ultrasensitive DNA aptasensors based on exponential amplification reaction

This is a comprehensive project for the development of a general method to enhance the sensitivity of DNA aptasensors by coupling them with an isothermal DNA amplification technique known as exponential amplification reaction (EXPAR). The method involves two steps: (1) first, the target-induced structure-switching of DNA aptamers causes the release of trigger oligonucleotides from the aptamers immobilized on a surface; (2) then, the released trigger oligonucleotides are amplified by the EXPAR technique for ultrasensitive detection. It is shown that the detection limit of a cocaine aptasensor is improved from 5 micromolar in assays without amplification to 0.8-1micromolar when EXPAR is applied, providing a 5-fold enhancement. The flexibility in designing the sequences of the trigger oligonucleotides enables the method generally applicable to other aptasensor systems such as thrombin aptamers. By EXPAR, the method has also achieved 10-fold enhancement in sensitivity from 4nM to 400 pM for thrombin detection, in comparison with similar assays without EXPAR.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Brown, Darius

Contributors dc:contributor

• Lu, Yi

• Aptasensor
• Cocaine
• Thrombin
• Exponential amplification reaction (EXPAR)
• Magnetic Beads
• Deoxyribonucleic acid (DNA)

Statement dc:rights

• Copyright 2013 Darius Z Brown

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/46916

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/46916