Related Experiment Video
Updated: Jun 24, 2026
09:33
Phthalic Acid Ester-Binding DNA Aptamer Selection, Characterization, and Application to an Electrochemical Aptasensor
Published on: March 21, 2018
DNA as a force sensor in an aptamer-based biochip for adenosine.
Dominik Ho1, Katja Falter, Philip Severin
1Lehrstuhl für Angewandte Physik and Center for Nanoscience, Ludwig-Maximilians-Universität, Amalienstrasse 54, 80799 Munich, Germany.
Analytical Chemistry
|April 15, 2009
Summary
This study introduces a novel label-free biochip for direct small molecule detection. The assay measures unbinding forces, enabling sensitive and selective identification of targets like adenosine without signal amplification.
Area of Science:
- Biotechnology
- Biosensing
- Molecular Interactions
Background:
- Current label-free biochip methods struggle with direct detection of small molecules due to low signal.
- Signal amplification is typically required, adding complexity to detection assays.
Purpose of the Study:
- To develop a label-free capture biochip for direct detection of small-molecule-aptamer interactions.
- To enable detection based on comparative unbinding force measurements.
Main Methods:
- A novel biochip immobilizes bipartite aptamers on glass supports via DNA duplexes.
- Unbinding forces of aptamer-ligand complexes are compared to reference DNA duplexes.
- Fluorescence readout quantifies broken bonds, with adenosine as a model target.
Main Results:
- The assay directly detects adenosine-aptamer interactions by measuring increased unbinding forces.
- Micromolar adenosine concentrations reliably shifted the bond breakage fractions.
- The method demonstrated selectivity against other nucleotides and multiplexing capabilities.
Conclusions:
- The developed force-based biochip allows label-free, direct detection of small molecules.
- The assay eliminates the need for washing steps or reporter molecules.
- This approach offers a sensitive and selective method for molecular detection in complex backgrounds.
