A sandwich dipstick assay for ATP detection based on split aptamer fragments

Area of Science:

• Biotechnology
• Biosensors
• Analytical Chemistry

Background:

• Aptamer-based strip assays are valuable for rapid, onsite detection due to their ease of use and low cost.
• Adenosine triphosphate (ATP) is a crucial biomarker in various biological and clinical applications.
• Developing sensitive and specific detection methods for ATP is essential for various diagnostic and monitoring purposes.

Purpose of the Study:

• To develop a novel, sensitive, and specific sandwich dipstick assay for the detection of adenosine triphosphate (ATP).
• To evaluate the performance of the developed assay in terms of sensitivity, linearity, and accuracy using urine samples.
• To assess the specificity of the assay against other common nucleotides.

Main Methods:

• Conjugation of a thiolated aptamer to gold nanoparticles (AuNPs).
• Immobilization of a biotin-aptamer on a nitrocellulose filter for the test line.
• Formation of a sandwich complex between split aptamer fragments and ATP, leading to an optical signal increase.
• Optimization of assay conditions and validation using urine samples.

Main Results:

• An excellent linear logarithmic response to ATP concentration was observed in the range of 0.5 μM to 5 mM.
• A limit of detection (LOD) of 0.5 μM was achieved at a signal-to-noise ratio of 3.
• The assay demonstrated good recovery (96-108%) and precision (RSD < 20%) in urine samples.
• High specificity was confirmed against other nucleotides like UTP, CTP, and GTP.

Conclusions:

• The developed aptamer-based dipstick assay is a sensitive, specific, and cost-effective tool for onsite ATP detection.
• The assay shows promise for use as a screening tool in biological fluids like urine.
• This method offers a simple and efficient approach for rapid ATP determination.