Organomercury oligonucleotide-polydopamine nanoparticle assemblies discriminate between target sequences by...

Area of Science:

• Bioconjugation Chemistry
• Nanoparticle-based Assays
• Nucleic Acid Chemistry

Background:

• Polydopamine nanoparticles offer versatile surface chemistry for biomolecule immobilization.
• Oligonucleotide probes are crucial tools in molecular diagnostics and research.
• Modifying oligonucleotides can alter their binding properties and enable new functionalities.

Purpose of the Study:

• To synthesize and characterize a fluorescently tagged oligonucleotide hybridization probe containing 5-mercuricytosine.
• To investigate the adsorption behavior of this modified probe on polydopamine nanoparticles.
• To evaluate the probe's release from nanoparticles upon hybridization with target sequences.

Main Methods:

• Synthesis of a fluorescently tagged oligonucleotide probe with a single 5-mercuricytosine residue.
• Adsorption studies comparing the modified probe with its unmetallated counterpart on polydopamine nanoparticles.
• Hybridization experiments to assess probe release dynamics based on target nucleobase pairing.

Main Results:

• The 5-mercuricytosine oligonucleotide probe exhibited significantly stronger adsorption to polydopamine nanoparticles compared to the unmodified probe.
• Hybridization with complementary target sequences induced probe release from the nanoparticles.
• The degree of probe release was dependent on the specific nucleobase opposite the 5-mercuricytosine during hybridization.

Conclusions:

• Incorporation of 5-mercuricytosine enhances oligonucleotide probe adsorption onto polydopamine nanoparticles.
• This modification enables a hybridization-triggered release mechanism from the nanoparticle surface.
• The differential release based on target nucleobase pairing suggests potential for developing sensitive nucleic acid detection systems.