Semi‐quantitative and quantitative detection of ochratoxin A in agricultural by‐products using a self‐assembling immunochromatographic strip

Abstract

BACKGROUND The toxicity and health risks of mycotoxins have encouraged increased awareness and strict monitoring of these contaminants in agricultural by‐products. In this paper, we developed and tested a sensitive, selective, and self‐assembling immunochromatographic (IC) strip for on‐site detection of ochratoxin A (OTA). We were able to demonstrate semi‐quantitative and quantitative detection of OTA in agricultural by‐product samples. RESULTS The optimized IC strip had a limit of detection (LOD) of 0.5 ng mL−1 OTA using the naked eye for semi‐quantitative detection. When a digitized strip reader was used to achieve quantitative results, the LOD for OTA was reduced to 0.1 ng mL−1 with a linear detection range of 0.1–10 ng mL−1. We also evaluated the specificity, stability, accuracy, and precision of the IC strip and demonstrated high performance in all of these areas. We then confirmed the ability of the IC strip to visually detect OTA contamination in authentic agricultural by‐product samples from the markets in China. Furthermore, quantitative detection of OTA using the IC strip showed that the concentration of OTA ranged from 1.7 to 101.3 ng g−1 in the positive agricultural by‐product samples, correlating well with the measurements obtained via liquid chromatography with tandem mass spectrometry. CONCLUSION The results indicated that this proposed IC strip was capable of sensitive, semi‐quantitative, quantitative, and on‐site detection of OTA contamination in agricultural by‐product samples. © 2020 Society of Chemical Industry

DNA‐bridged double gold nanoparticles‐based immunochromatography for dual‐mode detection of ochratoxin A

“…In addition, the CR showed a very weak for OTC, and negligible for other analogues and mycotoxins. Due to the same OTA‐mAb and OTA antigen had been used, this result was highly consistent with the specificity of ELISA, which was 85.8% for OTB and less than 10.2% than others (Mao et al., 2021). Therefore, the enhanced ICS had excellent specificity for detecting OTA, except for OTB.…”

“…Comparing the traditional ICS pattern (Mao et al., 2021), the enhanced ICS recommended the new signal pattern, which had based on the biotinylated DNA‐bridged double gold strategies. Although the proposed ICS might need more preparation (for the double AuNP probes and two conjugate pads) and multistep reaction (for the coupling of streptavidin–biotin and antigen–antibody) than the traditional ICS, the operation procedure and result interpretation for consumers were same as the traditional ICS.…”

“…To detect OTA contamination in the agricultural and its products, various chromatography‐based and immunoassay‐based methods had been developed, such as the HPLC (Mishra et al., 2016), thin‐layer chromatography (Teixeira et al., 2011), HPLC–MS (Delfino et al., 2022), ELISA (Sun et al., 2019), luminescent immunoassay (Zhang et al., 2019), and lateral flow immunochromatography strip (ICS) (Liu et al., 2008). Among them, the ICS methods had become the hotspot in view of its merits in feasibility, rapidity, economy in practice, and on‐site detection (Mao et al., 2021). Using the gold nanoparticle (AuNP) as detection marker, the ICS had been widely applied in various fields of disease diagnosis, food safety, and environment monitoring (Ren et al., 2015; Wang et al., 2022; Zhou et al., 2013).…”

Ultrasensitive fluorometric oligonucleotide immunoassay for the simultaneous and efficient detection of two mycotoxins in agricultural products

“…To prepare the fluorometric oligonucleotide probes, AuNPs were needed and were prepared according to the typical method of reducing HAuCl 4 . 37 In detail, 1.5 mL trisodium citrate solution (1%, w/v) was quickly added to 1 mL boiling HAuCl 4 solution (1%, w/v), which correspondingly formed 20 nm AuNPs. Then, the morphology and particle size of the AuNPs were identified via transmission electron microscopy.…”

Ultrasensitive monitoring strategy of PCR‐like levels for zearalenone contamination based DNA barcode

“…In addition to the instrument‐based methods, immunoassays have attracted widespread concern for ZEN monitoring, such as enzyme‐linked immunosorbent assays (ELISA), fluorescence immunoassays and immunochromatography assays 13–16 . These immunoassays improved the detection capability for ZEN, in addition to highlighting the advantages of sensitivity, rapidity, low cost and high‐throughput screening 17,18 . Because individuals now pay more attention to food safety and health, the toxic risk and accumulation effect of the lower ZEN contaminated levels should not be underestimated and also need monitoring 19,20 .…”