Visual aptamer-based capillary assay for ethanolamine using magnetic particles and strand displacement

Area of Science:

• Biotechnology
• Analytical Chemistry
• Biosensors

Background:

• Ethanolamine (EA) is a significant biomarker in various biological and industrial processes.
• Existing methods for EA detection can be time-consuming and require specialized equipment.
• Development of rapid, sensitive, and field-deployable assays for EA is crucial.

Purpose of the Study:

• To develop a novel aptamer-based capillary assay for the rapid and sensitive detection of ethanolamine (EA).
• To utilize a strand displacement mechanism with magnetic particles for visual signal generation.
• To evaluate the assay's performance in complex samples for potential point-of-care applications.

Main Methods:

• An aptamer-based capillary assay utilizing a strand displacement format with magnetic particles was designed.
• Capillary tubes were functionalized with complementary oligonucleotides and EA-aptamer-coated magnetic particles.
• Release and magnetic separation of DNA-coated magnetic particles upon EA binding generated visual spots.

Main Results:

• The assay achieved a visual limit of detection of 5 nM for ethanolamine.
• Incubation time was as short as 5 minutes, enabling rapid detection.
• Quantification was possible in the 5-75 nM range using digital photo analysis.
• The assay demonstrated robust performance in spiked tap water and serum samples.

Conclusions:

• The developed aptamer-based capillary assay offers a fast, visual, and sensitive method for ethanolamine detection.
• The assay's ability to perform in complex matrices suggests its suitability for real-world sample analysis.
• Integration with plastic capillaries, visual detection, and passive flow makes it ideal for point-of-care diagnostic devices.