Development and Validation of an Automated Magneto-Controlled Pretreatment for Chromatography-Free Detection of Aflatoxin B1 in Cereals and Oils through Atomic Absorption Spectroscopy

Abstract

A chromatography-free detection of aflatoxin B1 (AFB1) in cereals and oils through atomic absorption spectroscopy (AAS) has been developed using quantum dots and immunomagnetic beads. A magneto-controlled pretreatment platform for automatic purification, labeling, and digestion was constructed, and AFB1 detection through AAS was enabled. Under optimal conditions, this immunoassay exhibited high sensitivity for AFB1 detection, with limits of detection as low as 0.04 μg/kg and a linear dynamic range of 2.5–240 μg/kg. The recoveries for four different food matrices ranged from 92.6% to 108.7%, with intra- and inter-day standard deviations of 0.7–6.3% and 0.6–6.9%, respectively. The method was successfully applied to the detection of AFB1 in husked rice, maize, and polished rice samples, and the detection results were not significantly different from those of liquid chromatography-tandem mass spectrometry. The proposed method realized the detection of mycotoxins through AAS for the first time. It provides a new route for AFB1 detection, expands the application scope of AAS, and provides a reference for the simultaneous determination of multiple poisonous compounds (such as mycotoxins and heavy metals).

Recent Progress on Techniques in the Detection of Aflatoxin B1 in Edible Oil: A Mini Review

“…QDs-based sensors can adopt different working mechanisms and be applied to detect different substances, including AF S in edible oil [ 51 , 173 , 238 ]. According to the characteristics of QDs, Xuan et al [ 185 ] and Ye et al [ 241 ] developed and constructed different magnetic control pretreatment platforms, which were actually applied to the detection of AFB 1 in peanut oil and agricultural products, and both showed good detection characteristics. Other researchers used a quencher system composed of quantum dots and graphene oxide to detect AFB 1 in peanut oil, which also showed good detection characteristics [ 242 ].…”

Recent Advances in Mycotoxin Determination in Fish Feed Ingredients

“…Furthermore, a chromatography-free method was found in the literature for the detection of AFB1 in cereals and oils through atomic absorption spectroscopy (AAS) using quantum dots and immunomagnetic beads. A magneto-controlled pre-treatment platform for automatic purification, labeling, and digestion was constructed and AFB1 detection through AAS was enabled using the proposed immunoassay which exhibits high sensitivity for AFB1 detection in wheat and maize, with a LOD of 0.04 µg/kg [ 119 ].…”

Magnetic nanoparticle‐based immunosensors and aptasensors for mycotoxin detection in foodstuffs: An update

“…Since the AFB 1 in the sample extract was first purified by IMBs prior to competitively binding with QDs‐labeled AFB 1 antigens, this pretreatment system demonstrated exceptional specificity. Following this procedure, AFB 1 concentration was obtained by directly quantifying the signal probes (namely, Cd 2+ resulting from the acid digestion of QDs) using atomic absorption spectrometer (Ye et al., 2022) (Figure 5d). Furthermore, the indirect quantification of Cd 2+ through the electrochemical technique resulted in signal amplification and a wider linear range (0.08–800 vs. 2.5–240 µg/kg) (Xuan et al., 2020).…”

“…Those platforms shall effectively mitigate the impact of matrix effects and eliminate the need for labor‐intensive manual processing. Consequently, they streamline the processes of purifying, competitively binding, and releasing signals for mycotoxin detection (Xuan et al., 2020; Ye et al., 2022; Zhang, Liu et al., 2022). Wang's group utilized an in‐house, automatic platform to reduce the signal interference arising from cereal and oil samples (specifically wheat, corn, maize, husked rice, and peanut oil), which adopted IMBs as capture probes and QDs as signal probes.…”