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Sensitive analytical performance of folding based biosensor using methylene blue tagged aptamers
Gaëlle Catanante1, Rupesh K Mishra1, Akhtar Hayat2
1Laboratoire B.A.E., Université De Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France.
Talanta
|May 1, 2016
Summary
A novel electrochemical aptasensor was developed for Ochratoxin A (OTA) detection using methylene blue-tagged aptamers and hexamethylenediamine. This sensitive sensor accurately detects OTA in cocoa samples, offering a new strategy for food safety analysis.
Area of Science:
- Electrochemistry
- Biosensors
- Food Safety
Background:
- Ochratoxin A (OTA) is a prevalent mycotoxin in food, posing significant health risks.
- Existing methods for OTA detection often lack sensitivity, speed, or require complex sample preparation.
- Electrochemical aptasensors offer a promising alternative for sensitive and rapid toxin detection.
Purpose of the Study:
- To develop a novel folding-based electrochemical aptasensor for the sensitive detection of Ochratoxin A (OTA).
- To optimize aptamer immobilization strategies for enhanced sensor performance.
- To validate the aptasensor's efficacy in detecting OTA in complex food matrices like cocoa.
Main Methods:
- Development of an electrochemical aptasensor using methylene blue (MB) tagged anti-OTA aptamers immobilized on a screen-printed carbon electrode (SPCE).
- Investigation of various aptamer coupling strategies, with hexamethylenediamine (HDMA) showing optimal sensitivity.
- Detection principle based on conformational changes of the aptamer upon OTA binding, altering electron transfer efficiency.
Main Results:
- The developed aptasensor achieved a wide dynamic range (0.01-5 ng/mL) with a low limit of detection (LOD) of 0.01 ng/mL.
- Demonstrated high reproducibility (RSD% of 3.75) and a strong linear correlation (r=0.9976).
- Successfully applied to detect OTA in purified cocoa samples with good recovery rates (84-85%).
Conclusions:
- The study presents a robust and sensitive electrochemical aptasensor for OTA detection, utilizing a unique immobilization strategy with long carbon chain spacers.
- The sensor design provides a generalizable strategy for developing other folding-based electrochemical aptasensors.
- The aptasensor is effective for monitoring OTA contamination in complex food matrices, contributing to enhanced food safety.
