Immobilization-free multiplex electrochemical DNA and SNP detection

Area of Science:

• Electrochemistry
• Molecular Biology
• Nanotechnology

Background:

• Multiplex detection of DNA and single nucleotide polymorphisms (SNPs) is crucial for diagnostics.
• Existing methods often require complex probe immobilization, limiting efficiency and robustness.
• There is a need for simplified, sensitive, and reliable methods for genetic analysis.

Purpose of the Study:

• To develop a novel, immobilization-free electrochemical method for multiplex DNA and SNP detection.
• To utilize peptide nucleic acid (PNA) probes and indium tin oxide (ITO) electrodes for this purpose.
• To demonstrate the feasibility of sensitive and specific detection without probe attachment.

Main Methods:

• A label-free electrochemical detection strategy was employed.
• Neutrally charged peptide nucleic acid (PNA) probes labeled with electroactive indicators were used.
• A negatively charged indium tin oxide (ITO) electrode facilitated detection based on electrostatic repulsion.
• Hybridization of target DNA with PNA probes led to signal suppression.

Main Results:

• The method achieved immobilization-free detection of sequence-specific DNA and SNPs.
• Multiplex detection was realized by using distinguishable electroactive indicators on different PNA probes.
• Electrostatic repulsion between the DNA/PNA duplex and the ITO electrode surface caused signal suppression.
• No interference was observed during simultaneous detection of multiple targets.

Conclusions:

• A simple, robust, and immobilization-free electrochemical strategy for multiplex DNA and SNP detection has been established.
• This approach offers high sensitivity and specificity without the need for probe immobilization.
• The method shows significant potential for applications in point-of-care testing and genetic diagnostics.