基于CdSe阳离子交换的玉米赤霉烯酮新型荧光免疫检测方法的建立及应用

作为镰刀属真菌的次级代谢产物,玉米赤霉烯酮(zearalenone,ZEN)具有强烈的生殖毒性和免疫毒性,严重威胁动物和人类健康。本研究通过采用羧基修饰的CdSe水溶性量子点(quantum dots,QDs)标记ZEN单克隆抗体,并基于CdSe阳离子交换信号增强原理,建立了ZEN新型荧光免疫检测方法(CdSe QDs-FLISA),检测下限(IC₁₀)和半数抑制率(IC₅₀)分别为0.006 ng/mL和0.17 ng/mL,检测区间(IC₂₀-IC₈₀)为0.01-0.45 ng/mL。与ZEN的结构类似物(α-zearalanol、zearalanone、α-zearalenol、β-zearalenol and β-zearalanol)交叉反应性依次为22.3%、13.1%、6.2%、1.6%和3.9%,与农产品中其他真菌毒素如黄曲霉毒素B₁ (AFB₁)、赭曲霉毒素A (OTA)、呕吐毒素(DON)和伏马毒素B₁ (FB₁)几乎不存在交叉反应。该方法在玉米样本中加标回收率较高,且实际样本中ZEN的定量检测结果与LC-MS/MS一致性较好。本研究建立的CdSe QDs-FLISA操作简单,可实现对样本中ZEN的快速定量检测与分析,便于基层单位推广使用,具有较好的应用前景,同时也可为其他病原微生物检测技术的开发提供参考。

Sensitive fluorescence immunoassay for the detection of zearalenone base on signal amplification induced by cation exchange in CdSe quantum dots

Zearalenone (ZEN), an estrogenic and carcinogenic mycotoxin, is produced by Fusarium species, including Fusarium graminearum and Fusarium roseum. ZEN can pose threat to animals and humans through direct or indirect intake, as well as be transmitted to the fetus through placenta. Babies and children are more vulnerable to these effects than adults. A rapid and simple detection technique that is easy to operate and yet possesses a high sensitivity is preferred to monitor the ZEN in various foods. Herein, a fluorescence immunoassay via cation exchange reaction in CdSe quantum dots (CdSe QDs-FLISA) for detection of ZEN in cereal samples was outlined, with the detection range of 0.01-0.45 ng/mL and lower detective limit of 0.006 ng/mL. The Cd/Se QDs-FLISA had low cross-reactivity with the ZEN analogues α-zearalanol, zearalanone, α-zearalenol, β-zearalenol and β-zearalanol (22.3%, 13.1%, 6.2%, 1.6% and 3.9%, respectively), and no cross-reactivity (<0.01%) was observed with other mycotoxins, including aflatoxin B₁ (AFB₁), ochratoxin A (OTA), deoxynivalenol (DON), and fumonisin B₁ (FB₁). The average recoveries of the spiked corn samples ranged from 85.6% to 110.7% (CV levels ranged from 5.6% to 10.2%). Commercial contaminated sample ZEN quantification data were consistent with the sample LC-MS/MS detection results. The higher sensitivity and shorter testing time make this new approach an efficient technical support for the detection of trace amounts of ZEN in agriproducts. Additionally, this study also provides a reliable and feasible method for detecting other various targets in food safety monitoring fields.