基于核酸适配体传感器快速检测鸡蛋中氟虫腈

提出一种比色适配体传感器用于快速检测鸡蛋中氟虫腈。本方法建立基于核酸适配体特异性结合目标物的高选择性能和金纳米粒子标记聚合酶螯合物的双重信号放大效应，特异性、灵敏性地快速检测鸡蛋中氟虫腈。聚合酶螯合物上含有大约100 个脲酶，它能够催化尿素分解进而富集铜离子产生碱式碳酸铜，酸式铜离子显色剂可与碱式碳酸铜产生颜色变化，并且金纳米粒子在一定程度上也能催化沉积碱式碳酸铜，因此该方法可达到双重放大效果。同时，通过测定显色剂-铜离子配合物吸光度的变化对应计算鸡蛋中氟虫腈含量。结果表明，在最佳实验条件下，该方法检测限为0.072 μg/kg，并在0.1 μg/kg～50 mg/kg范围内具有较好的线性相关性，相关系数为0.998。此外该方法已经成功用于分析鸡蛋中氟虫腈，其结果与传统的胶体金免疫法测定结果一致。

Rapid Detection of Fluoronitrile in Egg Using Aptamer Sensor

A novel colorimetric aptamer sensor (aptasensor) was developed for rapid identification of fluoronitrile in egg samples. The assay was based on highly selective aptamer binding to its targets combined with the dual-amplification effect of the EnVision? polymerase chelate (EV) labeled with gold nanoparticles (AuNPs). This method could specifically and sensitively detect ultra-trace amounts of fluoronitrile in egg. EV contained approximately 100 urease molecules which could effectively catalyze decomposition of urea to enrich copper ions to produce basic copper carbonate. Color change of the chromogenic agent of acid copper ion could be generated by basic copper carbonate. In addition, gold nanoparticles could catalyze the deposition of basic copper carbonate to a certain extent. Thus, a dual-amplification effect could be achieved by using the proposed method. The amount of fluoronitrile in samples could be calculated by measuring the change in the absorbance of chromogenic agent-copper ion complex. The results indicated that under optimal conditions, the limit of detection was identified as 0.072 μg/kg and good linearity was observed within the concentration range of 0.1 μg/kg–50 mg/kg with a correlation coefficient of 0.998. This assay was successfully used to analyze fluoronitrile concentrations in egg samples with results consistent with those obtained by a conventional ELISA method.