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Surface modifications for enhanced immobilization of biomolecules: applications in biocatalysts and immuno-biosensor

Bai, Yunling
http://rave.ohiolink.edu/etdc/view?acc_num=osu1149085708

Abstract Details

2006, Doctor of Philosophy, Ohio State University, Chemical Engineering.
The goal of this study is to investigate the application of immobilization technology in various systems: immobilized cell/enzyme bioreactors, affinity chromatography, and BioMEM surface modification. These systems were investigated to solve a particular problem. A novel method for the co-immobilization of whole cells and LDH enzyme on cotton cloth was developed using poly (ethyleneimine) (PEI), which induced the formation of PEI-enzyme-cell aggregates and their adsorption onto cotton cloth, leading to multilayer co-immobilization of cells and enzyme with a high loading amount (0.5 g cell and 8 mg LDH per gram of cotton cloth) and activity yield (>95%). A fibrous bed bioreactor with cells and enzyme co-immobilized on the cotton cloth was then evaluated for R-HPBA production in fed-batch and repeated batch modes, which gave relatively stable reactor productivity. A novel surface treatment method using poly(ethyleneimine) (PEI), an amine-bearing polymer, was developed to enhance antibody binding on the poly(methyl methacrylate) (PMMA) microfluidic immunoassay device. By treating the PMMA surface of the microchannel on the microfluidic device with PEI, 10 times more active antibodies can be bound to the microchannel surface as compared to those without treatment or treated with the small amine-bearing molecule, hexamethylene diamine (HMD). Consequently, PEI surface modification greatly improved the immunoassay performance of the microfluidic device, making it more sensitive and reliable in the detection of IgG. The surface modification method was further simplified and optimized to enhance polymer-based microchannel ELISA for E. coli O157:H7 detection. By applying an amine-bearing polymer, poly (ethyleneimine) (PEI), onto a poly (methyl methacrylate) (PMMA) surface at pH higher than 11, PEI molecules were covalently attached and their amine groups were introduced to the PMMA surface. Zeta potential analysis and X-ray photoelectron spectroscopy (XPS) demonstrated that the alkaline condition is preferable for PEI attachment onto the PMMA surface. Compared to untreated PMMA microchannels, ~45 times higher signal and 3 times higher signal/noise ratio were achieved with the PEI surface treatment, which also shortened the time required for cells to bind to the microchannel surface to ~2 minutes, much less than that usually required for the same ELISA carried out in 96-well plates.
Shang-Tian Yang (Advisor)
221 p.
Engineering, Chemical
Surface Modification; Enzyme Immobilization; Cofactor Regeneration; Formate Dehydrogenase Purification; Biotransformation; Microfluidic Biosensor; ELISA; Foodborne Pathogen Detection

Recommended Citations

Citations

  • Bai, Y. (2006). Surface modifications for enhanced immobilization of biomolecules: applications in biocatalysts and immuno-biosensor [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1149085708

    APA Style (7th edition)

  • Bai, Yunling. Surface modifications for enhanced immobilization of biomolecules: applications in biocatalysts and immuno-biosensor. 2006. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1149085708.

    MLA Style (8th edition)

  • Bai, Yunling. "Surface modifications for enhanced immobilization of biomolecules: applications in biocatalysts and immuno-biosensor." Doctoral dissertation, Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1149085708

    Chicago Manual of Style (17th edition)

osu1149085708
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© 2006, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.
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