Wijayanti, SudarmaDita (2011) Electrochemical Characterization and Hybridization Efficiency of Aminated DNA Probes Immobilized on Screen Printed Carbon Electrodes. Magister thesis, Universitas Brawijaya.
Abstract
The research has focused on the how to attach DNA strands to carbon screen printed electrodes via an amino group, so that they stand up with a good orientation. This is to ensure the full length of the probe is available for hybridization. Electrodeposition at -1.0 V and covalent attachment of the aminated DNA probes by 1-ethyl-3-(3 dimethylaminopropyl)-carbodiimide (EDC) and N - Hydroxysuccinimide (NHS) . The DNA coverages and hybridization efficiencies were determined using both chronocoulometry and UV absorption. The use of propylamine as a spacer for the DNA strands, the effect of the propylamine : DNA ratio and the effect of the probe length were also examined. The best results were gained by immobilising pDNA-15 spacing with propylamine spacer at a 0.5 mole fraction ratio. Maximum ssDNA coverages determined by chronocoulometry were 1.37 x 10 13 molecules cm -2 obtained for electrodeposition and 4.97 x 10 12 molecules cm -2 for covalent attachment. The hybridization efficiencies ranged from 39.9 % to 80.3 %. These coverages were lower than those obtained by UV absorption. Measurement by UV-vis absorption does not involve the charge compensation assumptions required by the chronocoulometric method. The affinity constant (Ka) for duplex formation for the probes immobilized by covalent attachment ( 1.52 x 10 8 M -1 ) was higher than for the electrodeposition method ( 1.51 x 10 7 M -1 ) . Presumably, covalent attachment gave the ssDNA better orientation on the electrode in terms of allowing hybridization.
| Item Type: | Thesis (Magister) |
|---|---|
| Identification Number: | TES/572.86/WIJ/e/041100314 |
| Subjects: | 500 Natural sciences and mathematics > 572 Biochemistry > 572.8 Biochemical genetics |
| Divisions: | S2/S3 > Magister Teknologi Hasil Pertanian, Fakultas Teknologi Pertanian |
| Depositing User: | Endro Setyobudi |
| Date Deposited: | 22 Nov 2011 09:00 |
| Last Modified: | 22 Nov 2011 09:00 |
| URI: | http://repository.ub.ac.id/id/eprint/157705 |
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