Chemical-Modified Nucleotide-Based Elemental Tags for High-Sensitive Immunoassay

Area of Science:

• Biochemistry
• Analytical Chemistry
• Materials Science

Background:

• Inductively coupled plasma mass spectrometry (ICP-MS) is crucial for clinical diagnosis and single-cell analysis.
• Current ICP-MS immunoassay sensitivity is limited, often lower than fluorescence methods.
• Enhanced sensitivity requires elemental tags with a high density of metal atoms.

Purpose of the Study:

• To develop a new strategy for creating elemental tags with high loading of rare earth ions.
• To improve the sensitivity of ICP-MS-based biomolecular detection.
• To create versatile tags for applications in mass cytometry and clinical diagnostics.

Main Methods:

• Coupling alkyne-DNA chains with rare earth element (REE)-DOTA complexes via click chemistry.
• Utilizing PCR synthesis to prepare DNA chains with multialkynyl groups.
• Characterizing the elemental tags for their loading capacity and properties.

Main Results:

• Achieved elemental tags loaded with hundreds of rare earth ions.
• Demonstrated a sensitivity improvement of approximately 2 orders of magnitude compared to single metal-ion tags.
• Confirmed excellent water-solubility and biocompatibility of the DNA-based elemental tags.

Conclusions:

• The developed strategy effectively creates highly sensitive elemental tags for ICP-MS.
• These novel tags offer significant sensitivity enhancements for biomolecular analysis.
• The tags show strong potential for advancing mass cytometry and clinical diagnostic applications.