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Published on: February 28, 2015
Determination of aflatoxin M1 using an aptamer-based biosensor immobilized on the surface of dendritic fibrous
Houman Kholafazad Kordasht1, Mir-Hassan Moosavy1, Mohammad Hasanzadeh2
1Department of Food Hygiene and Aquatics, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran. mhmoosavy@gmail.com.
Abstract:
Aflatoxins are potential food pollutants produced by fungi. Among them, aflatoxin M1 (AF M1) is the most toxic. A great deal of concern is associated with AF M1 toxicity. Aflatoxins are potential food pollutants produced by fungi. Among them, aflatoxin M1 (AF M1) is the most toxic. A great deal of concern is associated with AF M1 toxicity. In the present work, a novel aptamer-based bioassay was developed for monitoring aflatoxin M1 (AF M1) in real samples. A chitosan-modified graphene quantum dot (GQD-CS) nanocomposite was used as a biocompatible substrate coated with dendritic fibrous nanosilica functionalized by amine groups (KCC-1-NH2-Tb). Accordingly, an innovative biocompatible polymeric matrix was prepared for aptamer immobilization. The unique oligonucleotide of AF M1 (5'-ATC CGT CAC ACC TGC TCT GAC GCT GGG GTC GAC CCG GAG AAA TGC ATT CCC CTG TGG TGT TGG CTC CCG TAT) labelled by toluidine blue was immobilized on the engineered interface. Hence, a novel aptamer-based bioassay was formed for the highly sensitive quantitation of AF M1 using cyclic voltammetry and differential pulse voltammetry techniques. The structure and morphology of GQDs-CS/KCC-1-NH2-Tb was investigated by Fourier transform infrared spectroscopy, X-ray diffraction, atomic force and scanning electron microscopy and energy-dispersive X-ray spectroscopy. The toxicity tests, which were performed by MTT assays, revealed the biocompatible nature of KCC-1-NH2-Tb. The engineered aptasensor demonstrated excellent behaviour toward the determination of AF M1, where the low limit of quantification was 10 fM. The proposed aptamer-based bioassay was successfully used for the monitoring of AF M1 in milk samples. This work provides a beneficial reference for the sensing of other toxins in food/pharmaceutical assays and veterinary medicine.
Insights
A novel aptamer-based bioassay was developed for detecting aflatoxin M1 (AF M1), a toxic food pollutant. This highly sensitive method successfully monitored AF M1 in milk samples, offering a new tool for food safety.
Area of Science:
- Biotechnology
- Analytical Chemistry
- Materials Science
Background:
- Aflatoxins, particularly aflatoxin M1 (AF M1), are highly toxic fungal food pollutants causing significant health concerns.
- Accurate and sensitive detection methods are crucial for monitoring AF M1 levels in food products.
- Existing detection methods may lack the sensitivity or practicality required for real-time food safety analysis.
Purpose of the Study:
- To develop a novel, highly sensitive aptamer-based bioassay for the quantitation of AF M1 in real samples.
- To engineer a biocompatible nanostructured matrix for efficient aptamer immobilization.
- To validate the performance of the developed aptasensor for AF M1 detection in food matrices.
Main Methods:
- Fabrication of a chitosan-modified graphene quantum dot (GQD-CS) nanocomposite substrate.
- Functionalization of the substrate with dendritic fibrous nanosilica (KCC-1-NH2-Tb) for aptamer immobilization.
- Development of an aptamer-based electrochemical sensor using cyclic voltammetry and differential pulse voltammetry.
- Characterization of the nanostructure using techniques like FTIR, XRD, AFM, SEM, and EDX.
- Toxicity assessment via MTT assays to confirm biocompatibility.
Main Results:
- The engineered aptasensor exhibited high sensitivity for AF M1 detection, with a low limit of quantification of 10 femtomolar (fM).
- The nanostructured substrate (GQD-CS/KCC-1-NH2-Tb) demonstrated excellent biocompatibility and suitability for aptamer immobilization.
- The developed bioassay was successfully applied to monitor AF M1 in real milk samples, showing promising results.
- Structural and morphological analyses confirmed the successful fabrication of the nanocomposite material.
Conclusions:
- A highly sensitive and biocompatible aptamer-based bioassay for AF M1 detection has been successfully developed.
- The novel nanostructured platform offers a promising approach for sensitive electrochemical sensing of food toxins.
- This method provides a valuable tool for ensuring food safety and can be adapted for detecting other contaminants.
