DNA analysis based on the local structural disruption to the duplexes carrying a luminous lanthanide complex

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Lanthanide complexes offer unique luminescent properties for biological detection.
• Developing sensitive and selective DNA assays is crucial for diagnostics and research.
• Split probes combined with luminescence provide a potential platform for nucleic acid detection.

Purpose of the Study:

• To develop a novel DNA assay utilizing luminous lanthanide complexes formed by split probes.
• To investigate the effect of base mispairing on the luminescence intensity of the lanthanide complex.
• To establish a nucleobase-discriminating principle for sequence-selective DNA detection.

Main Methods:

• Synthesized two DNA conjugates (split probes) functionalized with metal chelators.
• Formed integrated luminous lanthanide (Ln(3+)) complexes upon binding to complementary target DNA.
• Systematically introduced single-base mispairings around the lanthanide complex on the DNA template.
• Measured the luminescence intensity of the lanthanide complex under different mispairing conditions.

Main Results:

• The integrated lanthanide complex exhibited luminescence on the complementary DNA template.
• Luminescence intensity was sensitive to local structural disruptions caused by one-base mispairing.
• Vicinal mispairings near the lanthanide center significantly decreased emission intensity.
• The assay demonstrated sequence selectivity, distinguishing between perfectly matched and mismatched DNA.

Conclusions:

• A novel DNA assay based on luminescence changes of lanthanide complexes formed by split probes was established.
• The assay effectively discriminates DNA sequences by detecting luminescence modulation due to base mispairing.
• This method offers a new principle for nucleobase discrimination with potential applications in sensitive DNA analysis.