Fluorescence biosensor for the H₅N₁ antibody based on a metal-organic framework platform

Area of Science:

• Biotechnology
• Nanomaterials
• Analytical Chemistry

Background:

• Avian influenza (H5N1) poses a significant public health threat.
• Accurate and sensitive detection of H5N1 antibodies is crucial for disease surveillance and control.
• Existing detection methods may require complex procedures or specialized equipment.

Purpose of the Study:

• To develop a novel fluorescent biosensor for the sensitive detection of H5N1 antibodies.
• To utilize the adsorption properties of metal-organic frameworks (MOFs) with DNA for biosensing.
• To establish a reliable method for H5N1 antibody detection in biological samples.

Main Methods:

• A fluorescent DNA probe (5'6-FAM modified oligonucleotide) was designed.
• The DNA probe was adsorbed onto a metal-organic framework (MOF), leading to fluorescence quenching.
• Exonuclease I (Exo I) was used to release the fluorescent dye upon hydrolysis, with inhibition observed in the presence of H5N1 antibodies.

Main Results:

• The biosensor demonstrated fluorescence recovery upon Exo I hydrolysis of the DNA probe.
• Inhibition of Exo I hydrolysis by H5N1 antibodies prevented fluorescence recovery.
• A linear relationship was observed between fluorescence and the logarithm of H5N1 antibody concentration (1.0 × 10⁻⁶–5.0 × 10⁻⁹ mol L⁻¹).
• A detection limit of 1.6 × 10⁻⁹ mol L⁻¹ (S/N = 3) was achieved.

Conclusions:

• The developed MOF-DNA based fluorescent biosensor is effective for detecting H5N1 antibodies.
• The method exhibits high sensitivity and a low detection limit.
• The biosensor shows potential for application in real-world H5N1 antibody detection in serum samples.