Fluorescence anisotropy-based structure-switching aptamer assay using a peptide nucleic acid (PNA) probe

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Structure-switching aptamer assays are valuable for detecting specific molecules.
• Conventional DNA probes can limit assay sensitivity and performance.
• Peptide nucleic acids (PNAs) offer unique hybridization properties.

Purpose of the Study:

• To investigate the feasibility of using peptide nucleic acids (PNAs) as an alternative to DNA probes in structure-switching aptamer fluorescence polarization assays.
• To explore the impact of experimental parameters on PNA-based aptamer assay performance.
• To evaluate the detection capabilities for D-adenosine triphosphate (D-ATP).

Main Methods:

• Utilized two methodologies based on competitive hybridization between PNA/aptamer and target/aptamer complexes.
• Explored effects of PNA strand length, dye type, and buffer conditions.
• Employed fluorescence polarization to monitor assay response.

Main Results:

• Achieved linear detection of D-ATP in the range of 1 to 25 μM.
• Reached a detection limit (LOD) of 3 μM for D-ATP.
• Demonstrated a >5-fold lower LOD compared to conventional DNA-based aptamer assays.

Conclusions:

• Peptide nucleic acids (PNAs) are a viable and effective alternative to DNA probes in structure-switching aptamer assays.
• The PNA-based approach significantly improves detection limits for molecules like D-ATP.
• This method shows promise for enhanced molecular sensing platforms.