Related Experiment Video
Updated: May 28, 2026
03:38
Aptamer-Based Target Detection Facilitated by a 3-Stage G-Quadruplex Isothermal Exponential Amplification Reaction
Published on: October 6, 2022
Bifunctional colorimetric oligonucleotide probe based on a G-quadruplex DNAzyme molecular beacon
Libing Zhang1, Jinbo Zhu, Tao Li
1State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China.
Analytical Chemistry
|October 25, 2011
Summary
A novel bifunctional probe detects both DNA and thrombin protein using a colorimetric method. This innovative molecular beacon system offers a label-free approach for simultaneous biological analyses.
Area of Science:
- Biotechnology
- Molecular Biology
- Analytical Chemistry
Background:
- Developing sensitive and selective detection methods for both nucleic acids and proteins is crucial in molecular diagnostics.
- Existing methods often require multiple steps, labels, or specialized equipment, limiting their accessibility.
- There is a need for integrated, label-free biosensing platforms capable of simultaneous analyte detection.
Purpose of the Study:
- To develop a novel, label-free, bifunctional colorimetric probe for the simultaneous detection of single-stranded DNA and thrombin.
- To utilize a catalytic molecular beacon system incorporating a split G-quadruplex DNAzyme for signal generation.
- To demonstrate the feasibility of separate analysis of DNA and thrombin using this integrated probe.
Main Methods:
- Construction of a bifunctional molecular beacon probe with two hairpin structures containing a thrombin aptamer and a DNA-targeting sequence.
- Incorporation of a split G-quadruplex DNAzyme in the middle of the beacon for catalyzing a colorimetric reaction.
- Utilizing the H(2)O(2)-mediated oxidation of 3,3',5,5'-tetramethylbenzidine sulfate (TMB) for signal generation.
- Investigating the probe's response to the presence of target DNA and thrombin, observing the dissociation of the G-quadruplex and subsequent change in catalytic activity.
Main Results:
- The developed probe successfully detected both single-stranded DNA and thrombin in a label-free manner.
- The G-quadruplex DNAzyme effectively catalyzed the colorimetric reaction, producing a measurable signal.
- Binding of either target DNA or thrombin led to the dissociation of the G-quadruplex, resulting in a quantifiable decrease in catalytic activity.
- The system enabled the separate analysis of DNA and thrombin based on the observed signal changes.
Conclusions:
- A novel bifunctional colorimetric probe based on a catalytic molecular beacon and a split G-quadruplex DNAzyme has been successfully developed.
- This probe offers a sensitive, selective, and label-free platform for the simultaneous detection and separate analysis of DNA and thrombin.
- The findings present a promising approach for developing integrated biosensing systems for complex biological sample analysis.
