A DNA biosensor based on the detection of doxorubicin-conjugated Ag nanoparticle labels using solid-state voltammetry

Area of Science:

• Electrochemistry
• Biosensor Technology
• Molecular Diagnostics
• Avian Influenza Research

Background:

• Avian influenza virus, particularly H5N1, poses a significant threat to global health.
• Accurate and rapid detection of viral genetic material is crucial for disease control.
• Existing diagnostic methods may require complex procedures or specialized equipment.

Purpose of the Study:

• To develop and characterize a novel electrochemical biosensor for the detection of avian flu virus (H5N1) DNA.
• To establish a sensitive and quantitative method for identifying specific H5N1 oligonucleotide sequences.
• To demonstrate the utility of silver nanoparticles and doxorubicin as labels in DNA detection.

Main Methods:

• Fabrication of a gold electrode modified with thiolated DNA probes complementary to the target H5N1 sequence.
• Hybridization of target H5N1 DNA with the immobilized probes to form double-stranded DNA (ds-DNA).
• Labeling of ds-DNA with silver nanoparticles conjugated to doxorubicin.
• Detection of silver nanoparticle labels via cyclic voltammetry in KCl solution, monitoring the Ag/AgCl redox process.

Main Results:

• Successful fabrication of an electrochemical DNA biosensor for H5N1 detection.
• Demonstrated hybridization and labeling of target DNA sequences.
• Achieved a highly sensitive detection limit of 1 picomolar (pM) for the target H5N1 DNA oligonucleotide.

Conclusions:

• The developed electrochemical biosensor offers a sensitive and quantitative approach for H5N1 DNA detection.
• The combination of silver nanoparticles and doxorubicin provides an effective labeling strategy.
• This biosensor holds potential for rapid diagnostics of avian influenza virus.