Display Full Text | Download Full Text
3.57 MB PDF file

Degree

PhD, University of Cincinnati, Engineering : Environmental Engineering, 2006.

Abstract

In this research, a new disposable polymer lab-on-a-chip with micro biosensor has been designed, fabricated, and characterized for magnetic bead-based immunoassay, and applied to the detection of prostate cancer specific antigen as clinical application. A new electroplated permalloy micro array type magnetic bead separator, and an IDA microelectrode electrochemical sensor on polymer substrate realized in this work, have also overcome the integration difficulties considered in the previous magnetic bead separators and microelectrode sensor. Integration of the magnetic bead separator and IDA microelectrode sensor has been successfully achieved onto polymer lab-on-a-chip platform for magnetic bead-based immunoassay using innovative embedment technique of metal micro pattern into polymer substrate. For the successful demonstration of magnetic bead-based biochemical detection system and analysis concept, a full immunoassay has been performed in the developed disposable polymer lab-on-a-chip. The immunoassay results have proved that the developed lab-on-a-chip promises great potential in fast and small volume biochemical detection and analysis system for numerous applications in biotechnology. The developed system has been fully characterized: (1) dynamic range of sensor; (2) contribution of incubation time on the signal intensity; and (3) effect on the signal intensity of the sensor’s proximity to beads. Fast (less than 35 minutes) and small volume (5 uL of immunoassay reagent) immunoassay has been successfully performed and demonstrated in developed disposable polymer lab-on-a-chip producing very promising analysis results towards a generic biochemical detection and analysis system. Low detection limit of 16.4 ng/mL have been successfully achieve by magnetic bead-based immunoassay for mouse IgG detection. As clinical application, magnetic bead-based electrochemical immunoassay on the on the lab-on-a-chip has been demonstrated for the detection of PSA (prostate cancer specific antigen). This method has been successfully used for the detection of PSA in the concentration range of 25 ng/mL to 1000 ng/mL with 0.706 nA?mL/s?ìg sensitivity which is two order magnitude higher than previous work and a entire detection was completed just in 35 min including sample preparation and detection. The methodology and system, which is developed in this work, can be also applied to generic biomolecule detection and analysis systems by replacing antibody/antigen with appropriate bio receptors/reagents such as DNA fragments or oligonucleotides for the application to DNA analysis and/or high throughput protein analysis.

Keywords

Immunoassay; ELISA; Electrochemical detection; magnetic bead; Interdigitated array microelectrode; MEMS

Advisor

Dr. Chong H. Ahn

Pages

122p.

Document number: ucin1164035684
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1164035684

★

This ETD has been downloaded 1564 times (through March 2013)

This ETD was one of the top ten most frequent downloads of January 2008.