Preparation of Functionalized Immunomagnetic Beads and Their Application in the Detection of AFB1 in Corn, Oat, and...

Aflatoxin B1 (AFB1) is widespread in various kinds of food and poses a serious threat to health when it enters the human body via the food chain.

This study aimed to establish a rapid and sensitive method for the detection of AFB1 and then combine it with HPLC for the quantitative analysis of AFB1 content.

In this work, hydrothermal and sol-gel methods were employed to prepare aminated magnetic nanoparticles featuring strong magnetism and excellent dispersion. Magnetic nanoparticles bound with antibodies can specifically capture AFB1 and then be combined with HPLC for the quantitative analysis of AFB1 content. Moreover, the key factors influencing the extraction efficiency, such as buffer type, adsorption time, elution time and volume, were optimized.

The samples were spiked with AFB1 at low, medium, and high concentration levels of 5.0, 10.0, and 20.0 μg/kg, respectively. The established method exhibits good linearity within the range of 0.1-100 µg/kg, and the detection limit is as low as 0.09 µg/kg (S/N = 3). The recoveries in real samples ranged from 79.33 to 111.51%, with all RSDs being less than 11.16% (n = 3 for each level).

In conclusion, a rapid and efficient analytical method for detecting AFB1 in corn, peanut, and oat based on functionalized immunomagnetic beads (IMBs) coupled with high-performance liquid chromatography with a fluorescence detector (HPLC-FLD) have been successfully developed. The method exhibited excellent sensitivity, featuring a low method detection limit of 0.09 μg/kg, high accuracy, and remarkable precision. In comparison to traditional sample preparation techniques, this IMB-based approach presents substantial advantages in terms of simplicity, rapidity (completing sample processing within approximately 30 min), and cost-effectiveness.

The IMBs possess excellent magnetic separation capabilities, which effectively streamlines the pre-processing steps.