ATP detection using a label-free DNA aptamer and a cationic tetrahedralfluorene

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Adenosine triphosphate (ATP) is a crucial molecule in biological systems.
• Accurate detection of ATP is vital for various research and diagnostic applications.
• Existing fluorescent ATP detection methods often require multiple labels, increasing complexity.

Purpose of the Study:

• To develop a simple, sensitive, and selective label-free method for ATP detection.
• To utilize a DNA aptamer as a recognition element and ethidium bromide (EB) as a signal reporter.
• To enhance detection performance using a light-harvesting cationic tetrahedralfluorene.

Main Methods:

• A label-free DNA aptamer was designed for specific ATP recognition.
• The aptamer undergoes a conformational change upon ATP binding, altering its duplex structure.
• Ethidium bromide (EB) fluorescence was monitored, which changes upon intercalation into the aptamer structure.
• A cationic tetrahedralfluorene was employed as an energy donor to sensitize EB emission.

Main Results:

• The label-free aptamer assay demonstrated good selectivity for ATP over other nucleotides (CTP, GTP, UTP).
• Using EB alone, the detection limit for ATP was approximately 0.2 mM.
• The introduction of tetrahedralfluorene as an energy donor improved the detection limit by 10-fold and selectivity by 2-fold.
• The enhanced assay showed sensitivity and selectivity comparable to or better than existing multi-label fluorescent ATP assays.

Conclusions:

• A novel, label-free fluorescent assay for ATP detection using DNA aptamers and EB has been successfully developed.
• The assay offers a simple and sensitive platform for ATP quantification.
• The use of a light-harvesting molecule significantly enhances the assay's performance, providing a competitive alternative to complex multi-label methods.