Sequence-specific gene detection with a gold electrode modified with DNA probes and an electrochemically active dye

Area of Science:

• Biosensors
• Molecular Diagnostics
• Electrochemistry

Background:

• Oncogenes play a crucial role in cancer development.
• Sensitive and specific detection of oncogene sequences is vital for early diagnosis and targeted therapy.
• Existing detection methods often require complex procedures or expensive equipment.

Purpose of the Study:

• To develop a novel electrochemical biosensor for the sequence-specific detection of oncogene v-myc.
• To investigate the use of Hoechst 33258 as a DNA minor groove binder and electrochemical indicator.
• To establish a quantitative method for detecting target DNA within a specific concentration range.

Main Methods:

• Immobilization of a synthesized 20-mer DNA probe complementary to v-myc on a gold electrode via chemisorption.
• Voltammetric detection using Hoechst 33258, a DNA minor groove binder and electrochemically active dye.
• Hybridization of the modified electrode with target DNA and measurement of anodic peak current (ipa).

Main Results:

• The immobilized DNA probe selectively bound Hoechst 33258, resulting in a higher anodic peak current compared to a bare gold electrode.
• Hybridization with the target oncogene v-myc DNA (pVM623) significantly increased the anodic peak current.
• A sequence-specific detection was achieved, with the anodic peak current correlating to target DNA concentration from 10(-7) to 10(-13) g/mL.

Conclusions:

• The developed electrochemical biosensor enables sensitive and sequence-specific detection of oncogene v-myc.
• Hoechst 33258 serves as an effective indicator for DNA hybridization events on the electrode surface.
• This method offers a promising approach for quantitative molecular diagnostics of oncogenes.