A label free aptasensor for Ochratoxin A detection in cocoa beans: An application to chocolate industries.
Contamination of food by mycotoxin occurs in minute/trace quantities. Nearly 92.5% of the cocoa samples present Ochratoxin A (OTA) levels at trace quantity. Hence, there is a necessity for a highly sensitive and selective device that can detect and quantify these organic toxins in various matrices such as cocoa beans. This work reports for the first time, a facile and label-free electrochemical impedimetric aptasensor for rapid detection and quantitation of OTA in cocoa beans. The developed aptasensor was constructed based on the diazonium-coupling reaction mechanism for the immobilization of anti-OTA-aptamer on screen printed carbon electrodes (SPCEs). The aptasensor exhibited a very good limit of detection (LOD) as low as 0.15 ng/mL, with added advantages of good selectivity and reproducibility. The increase in electron transfer resistance was linearly proportional to the OTA concentration in the range 0.15-2.5 ng/mL, with an acceptable recovery percentage (91-95%, RSD = 4.8%) obtained in cocoa samples. This work can facilitate a general model for the detection of OTA in cocoa beans based on the impedimetric aptasensor. The analysis can be performed onsite with pre-constructed and aptamer modified electrodes employing a portable EIS set up.
IMAGES, Université De Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France.
Rupesh K
RK
Mishra
IMAGES, Université De Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France; Interdisciplinary Research Centre in Biomedical Materials (IRCBM), COMSATS Institute of Information Technology (CIIT), Lahore 54000, Pakistan.
Akhtar
A
Hayat
IMAGES, Université De Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France.
Gaëlle
G
Catanante
IMAGES, Université De Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France.
Cristina
C
Ocaña
IMAGES, Université De Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan Cedex 66860, France. Electronic address: jlmarty@univ-perp.fr.
Jean-Louis
JL
Marty
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques; D002099:Cacao / Q000378:metabolism*; D002244:Carbon / Q000737:chemistry; D058266:Dielectric Spectroscopy; D004566:Electrodes; D005292:Ferricyanides / Q000737:chemistry; D005506:Food Contamination / Q000032:analysis; D057230:Limit of Detection; D009793:Ochratoxins / Q000032:analysis*; D015203:Reproducibility of Results
D052157:Aptamers, Nucleotide; D005292:Ferricyanides; D009793:Ochratoxins; C007931:hexacyanoferrate III; C025589:ochratoxin A; D002244:Carbon
Aptasensor; Cocoa beans; Impedimetric; Label free; Ochratoxin; Screen printed electrodes