Aflatoxin B1 (AFB1) is one of the mycotoxins with the most dangerous poisons and poses a threat to living things. Several detection methods for Aflatoxin B1 (AFB1) with high sensitivity (LC-MS technique, HPLC, ELISA, etc.) still require lengthy preparation time and are not real-time and portable. Aflatoxin B1 (AFB1) detection is one of the major challenges in the field of food safety because Aflatoxin B1 (AFB1) attacks the food and agricultural products sector. One of the potential sensors that can be used as a base for Aflatoxin B1 (AFB1) detection is the Quartz Crystal Microbalance (QCM) sensor. This study examines the performance of the Quartz Crystal Microbalance (QCM) sensor as one of the Aflatoxin B1 detection techniques through the physical deposition method. The Quartz Crystal Microbalance (QCM) sensor modified uses polyvinyl acetate (PVAc) material as a container to embed a molecular model that will be detected through a molecular imprinting polymer (MIP) process coated on QCM using the electrospinning method. The response results show that the value of the sensor response using the MIP process is more significant than without the MIP process. The sensor characteristics demonstrated by the PVAc/AFB 50 sample have a limit of detection (LOD) value is 0.63 ppb, and a limit of quantitation (LOQ) is 1.91 ppb with a coefficient correlation is 0.97 for testing with a concentration range of 5.0 – 40.0 ppb. Therefore, the MIP process in QCM provides a favorable response for the detection of AFB1 in the future.

Aflatoxins (AFs) are highly toxic compounds that can cause both acute and chronic toxicity in humans. Aflatoxin B1 (AFB1) is considered the most toxic of AFs. Therefore, the rapid and on-site detection of AFB1 is critical for food safety management. Here, we report the on-site detection of AFB1 in grains by a portable surface plasmon resonance (SPR) sensor. For the detection of AFB1, the surface of an SPR Au chip was sequentially modified by cysteine-protein G, AFB1 antibody, and bovine serum albumin (BSA). Then, the sample solution and AFB1-BSA conjugate were flowed onto the Au chip in serial order. In the absence of AFB1, the SPR response greatly increased due to the binding of AFB1-BSA on the Au chip. In the presence of AFB1, the SPR response showed little change because the small AFB1 molecule binds on the Au chip instead of the large AFB1-BSA molecule. By using this portable SPR-based competitive immunoassay, the sensor showed low limits of detection (2.51 ppb) and quantification (16.32 ppb). Furthermore, we successfully detected AFB1 in rice, peanut, and almond samples, which suggests that the proposed sensing method can potentially be applied to the on-site monitoring of mycotoxins in food.

A reusable sandwiched electrochemical piezoelectric immunosensor has been developed for aflatoxin B1 (AFB1) detection using gold coated iron oxide core-shell (Au-Fe₃O₄) nanostructure. The monoclonal anti-aflatoxin antibody (aAFB1) was immobilized on self-assembled monolayer of 4-aminothiophenol on gold coated quartz crystal to fabricate immunoelectrode (BSA/aAFB1/4-ATP/Au). In addition, secondary rabbit-immunoglobulin antibodies (r-IgGs) functionalized with Au-Fe₃O₄NPs via cysteamine (r-IgG-Cys-Au-Fe₃O₄) were allowed to interact with AFB1. Both competitive and noncompetitive strategies were employed and a competition between coated AFB1 and free AFB1 was carried out. The competitive mode shows higher linear range (0.05 to 5 ng mL⁻¹) than the noncompetitive one (0.5 to 5 ng mL⁻¹), high sensitivity 335.7 µA ng⁻¹ mL cm⁻², and LOD 0.07 ng mL⁻¹. The fabricated immunosensor has been tested using cereal samples spiked with different concentrations of AFB1. The developed competitive immunoelectrode displays good reproducibility, and storage stability and regenerated with negligible loss in activity through removal of the r-IgG-Cys-Au-Fe₃O₄conjugate using a strong external magnet.

Aflatoxins are toxic carcinogenic secondary metabolites produced predominantly by two fungal species: Aspergillus flavus and Aspergillus parasiticus. These fungal species are contaminants of foodstuff as well as feeds and are responsible for aflatoxin contamination of these agro products. The toxicity and potency of aflatoxins make them the primary health hazard as well as responsible for losses associated with contaminations of processed foods and feeds. Determination of aflatoxins concentration in food stuff and feeds is thus very important. However, due to their low concentration in foods and feedstuff, analytical methods for detection and quantification of aflatoxins have to be specific, sensitive, and simple to carry out. Several methods including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), mass spectroscopy, enzyme-linked immune-sorbent assay (ELISA), and electrochemical immunosensor, among others, have been described for detecting and quantifying aflatoxins in foods. Each of these methods has advantages and limitations in aflatoxins analysis. This review critically examines each of the methods used for detection of aflatoxins in foodstuff, highlighting the advantages and limitations of each method. Finally, a way forward for overcoming such obstacles is suggested.