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Design and Development of Aptamer–Gold Nanoparticle Based Colorimetric Assays for In-the-field Applications
Published on: June 23, 2016
Aptamer-based colorimetric biosensing of Ochratoxin A using unmodified gold nanoparticles indicator
Cheng Yang1, Yong Wang, Jean-Louis Marty
1State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
Biosensors & Bioelectronics
|October 26, 2010
Summary
This study introduces a rapid, five-minute aptasensor for detecting Ochratoxin A (OTA). The sensor utilizes gold nanoparticles (AuNPs) and a color change to identify OTA presence, offering a new method for toxin detection.
Area of Science:
- Biosensors
- Nanotechnology
- Analytical Chemistry
Background:
- Ochratoxin A (OTA) is a prevalent mycotoxin with significant health implications.
- Accurate and rapid detection methods for OTA are crucial for food safety and public health.
Purpose of the Study:
- To develop a novel aptasensor for the sensitive and rapid detection of Ochratoxin A (OTA).
- To investigate the conformational changes of OTA aptamers induced by OTA binding and their effect on gold nanoparticle aggregation.
Main Methods:
- Utilized unmodified gold nanoparticles (AuNPs) as an indicator.
- Exploited the salt-induced aggregation phenomenon of AuNPs.
- Employed Circular Dichroism (CD) spectroscopy to analyze aptamer conformational changes.
- Developed a colorimetric assay for visual detection.
Main Results:
- Demonstrated that OTA binding induces a conformational shift in the aptamer to a G-quadruplex structure.
- Observed that the compact G-quadruplex structure facilitates salt-induced AuNPs aggregation, leading to a visible color change (red to blue).
- Achieved a rapid assay time of five minutes.
- Established a linear detection range for OTA from 20 to 625 nM with a detection limit of 20 nM.
Conclusions:
- The developed aptasensor provides a fast, visual, and sensitive method for OTA detection.
- The study elucidates the mechanism of aptamer conformational change driving the colorimetric response.
- This approach holds promise for practical applications in food safety monitoring.
