An On-Site, Ultra-Sensitive, Quantitative Sensing Method for the Determination of Total Aflatoxin in Peanut and Rice Based on Quantum Dot Nanobeads Strip

Abstract

An on-site, ultra-sensitive, and quantitative sensing method was developed based on quantum dot nanobeads (QDNBs) and a test strip for the determination of total aflatoxins (AFTs) in rice and peanuts. The monoclonal antibody against AFT (mAbAFT) was homemade and labeled with QDNB. After the pre-coating of the AFT antigen on the test line (T line), the competitive immunoreactions were conducted between AFT and AFT antigen on the T line with QDNBs-mAbAFT. Under optimal conditions, this approach allowed a rapid response towards AFT with a considerable sensitivity of 1.4 pg/mL and 2.9 pg/mL in rice and peanut matrices, respectively. The put-in and put-out durations were within 10 min. The recoveries for AFT in rice and peanut sample matrices were recorded from 86.25% to 118.0%, with relative deviations (RSD) below 12%. The assay was further validated via the comparison between this QDNB strip and the conventional HPLC method using spiked samples. Thus, the design provided a potential alternative for on-site, ultra-sensitive, and quantitative sensing of AFT that could also be expanded to other chemical contaminants for food safety.

Advantages of Lateral Flow Assays Based on Fluorescent Submicrospheres and Quantum Dots for Clostridium difficile Toxin B Detection

“…QDNBs–mAb conjugates were prepared by following previously published QDNBs antibody conjugation protocol [ 26 ]. Briefly, 3 mL of QDNBs solution was dispersed in 0.05 M MES (2-[N-morpholino]ethanesulfonicacid, pH 6.0) and activated with 12 mg of EDC and 18 mg of NHS at room temperature for 15 min.…”

Evaluating the Performance of Lateral Flow Devices for Total Aflatoxins with Special Emphasis on Their Robustness under Sub-Saharan Conditions

“…Peeled almonds and peanuts showed a positive result at the cutoff level, whereas the unpeeled nuts showed a positive result slightly above the cutoff level in the test that was used. The work from Zhang et al analyzed the aflatoxins in peanuts and other commodities [22,23] and reported good recoveries when testing with different matrices such as nut samples.…”

Quantum Dots as Biosensors in the Determination of Biochemical Parameters in Xenobiotic Exposure and Toxins

“…70 Ouyang et al reported antibody-antigen interaction based detection of aflatoxin using quantum dot nanobeads with the LODs of 1.4 and 2.9 pg/mL for rice and peanut samples, respectively. 71 Other QD-based Immunochromatographic assays have been widely employed in the analysis of AFTs (mainly for AFB1). 72 Zearalenone (ZEA) also known as RAL and F-2 mycotoxin is a macrocyclic β-resorcyclic acid lactone and a nonesteroidalestrogenic mycotoxin produced by some Fusarium and Gibberella species.…”