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A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay
Published on: February 28, 2015
Sensitive and visual detection of sequence-specific DNA-binding protein via a gold nanoparticle-based colorimetric
Li-Juan Ou1, Pei-Yan Jin, Xia Chu
1State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China.
Analytical Chemistry
|June 23, 2010
Summary
A new colorimetric biosensing strategy uses exonuclease III (Exo III) to detect DNA-binding proteins. This method offers a stable, visual indicator for DNA-protein interactions, enhancing robustness and convenience.
Area of Science:
- Biotechnology
- Nanotechnology
- Molecular Biology
Background:
- Detecting sequence-specific DNA-binding proteins is crucial for understanding gene regulation.
- Existing methods often rely on fluorescence and require time-dependent monitoring, limiting robustness.
Purpose of the Study:
- To develop a rapid, sensitive, and visual colorimetric biosensing strategy for DNA-binding proteins.
- To leverage exonuclease III (Exo III) protection for a more robust and convenient assay.
Main Methods:
- Developed a strategy based on Exo III protection of DNA-cross-linked gold nanoparticle (AuNP) aggregates.
- Utilized stable DNA protection by protein binding within AuNP networks for a static colorimetric signal.
- Introduced thioctic acid for stable DNA tethering on AuNPs, avoiding thiol interferences.
Main Results:
- Demonstrated a novel, stable protection mechanism of DNA by protein binding in AuNP aggregates.
- Achieved a static color transition indicator, eliminating the need for time-dependent monitoring.
- Successfully detected TATA binding protein with a linear response range of 0–120 nM and a detection limit of 10 nM.
Conclusions:
- The developed Exo III protection-based colorimetric biosensor provides a robust, convenient, and visually detectable method for DNA-binding proteins.
- This strategy offers an improvement over conventional fluorescence assays by providing a static indicator.
- The method is specific, simple, and quantitative, with potential applications in various biological studies.
