DNA Hybridization Detection at Heated Electrodes
| Autor: | Joseph Wang, Jörg Dipl.-Biochem. Peter, Gerd-Uwe Flechsig, Gerhard Hartwich, Peter Prof. Dr. Gründler |
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| Rok vydání: | 2005 |
| Předmět: |
Detection limit
Time Factors Surface Properties Chemistry DNA–DNA hybridization Temperature Analytical chemistry Nucleic Acid Hybridization DNA Surfaces and Interfaces Electrolyte Condensed Matter Physics Chip Electrochemistry Sensitivity and Specificity law.invention law Electrode General Materials Science Gold Self-assembly Alternating current Electrodes Spectroscopy |
| Zdroj: | Langmuir. 21:7848-7853 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la051176n |
| Popis: | The detection of DNA hybridization is of central importance to the diagnosis and treatment of genetic diseases. Due to cost limitations, small and easy-to-handle testing devices are required. Electrochemical detection is a promising alternative to evaluation of chip data with optical readout. Independent of the actual readout principle, the hybridization process still takes a lot of time, hampering daily use of these techniques, especially in hospitals or doctor's surgery. Here we describe how direct local electrical heating of a DNA-probe-modified gold electrode affects the surface hybridization process dramatically. We obtained a 140-fold increase of alternating current voltammetric signals for 20-base ferrocene-labeled target strands when elevating the electrode temperature during hybridization from 3 to 48 degrees C while leaving the bulk electrolyte at 3 degrees C. At optimum conditions, a target concentration of 500 pmol/L could be detected. Electrothermal regeneration of the immobilized DNA-probe strands allowed repetitive use of the same probe-modified electrode. The surface coverage of DNA probes, monitored by chronocoulometry of hexaammineruthenium(III), was almost constant upon heating to 70 degrees C. However, the hybridization ability of the probe self-assembled monolayer declined irreversibly when using a 70 degrees C hybridization temperature. Coupling of heated electrodes and highly sensitive electrochemical DNA hybridization detection methods should enhance detection limits of the latter significantly. |
| Databáze: | OpenAIRE |
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