DNA sensor based on vapour polymerised pedot films functionalised with gold nanoparticles

Area of Science:

• Electrochemistry
• Nanotechnology
• Molecular Diagnostics

Background:

• Poly-3,4-ethylenedioxythiophene (PEDOT) is a conductive polymer with applications in biosensing.
• Gold nanoparticles (AuNPs) enhance sensor performance through increased surface area and conductivity.
• Detecting pathogens like Staphylococcus aureus (S. aureus) is crucial for diagnosing mammary gland inflammation.

Purpose of the Study:

• To develop a sensitive and rapid electrochemical biosensor for S. aureus DNA detection.
• To create a novel nanocomposite material for enhanced signal transduction.
• To establish a detection method that bypasses the need for nucleic acid amplification.

Main Methods:

• Vapor-phase polymerization of PEDOT on gold electrodes.
• Electrodeposition of gold nanoparticles to form a PEDOT-AuNP nanocomposite.
• Immobilization of thiolated capture DNA for target hybridization.
• Electrochemical detection using horse radish peroxidase (HRP) labeled probes and hydroquinone redox cycling.

Main Results:

• The PEDOT-AuNP nanocomposite facilitated efficient immobilization and hybridization.
• The biosensor demonstrated a linear response to S. aureus DNA over a concentration range of 150 pM to 1 μM.
• Detection limits in the picomolar (pM) range were achieved without PCR or NASBA amplification.

Conclusions:

• The developed electrochemical biosensor offers a sensitive and label-free method for S. aureus DNA detection.
• The PEDOT-AuNP nanocomposite platform shows promise for rapid pathogen diagnostics.
• This approach could be valuable for early detection of mammary gland inflammation.