基于脱氧核酶的高通量荧光法测定大米中的铅

Determination of lead in rice by high-throughput fluorescence method based on DNAzyme

中文关键词:  脱氧核酶  高通量  荧光法  铅

英文关键词:DNAzyme  high-throughput  fluorescence method  lead

中文摘要:

      目的 建立了一种基于脱氧核酶(DNAzyme)的高通量荧光法检测大米中铅的方法。方法 标记淬灭基团的GR-5 DNAzyme与标记荧光基团的底物DNA的互补结构能特异识别铅离子, 从而催化剪切底物DNA的rA位点, 使得切断的底物DNA解离同时释放荧光, 荧光强度与铅离子浓度相关联, 应用荧光定量PCR仪, 多个样本的荧光能获得同时检测。结果 该方法检测铅的特异性高, 线性范围为0.001~0.1 mg/kg, 相关系数r2为0.991, 检出限为0.0008 mg/kg。结论 该方法简便易用、能耗低、灵敏度高, 适合应用于大批量样本中铅的高通量测定, 对于日益增长的食品检验检测需求和日趋严格的食品安全监管要求具有重要意义。

英文摘要:

      Objective To establish a method for the determination of lead in rice by high-throughput fluorescence method based on DNAzyme. Methods The complementary structure of the GR-5 DNAzyme labeled with the quenching group and the substrate DNA labeled with the fluorophore can specifically recognize the lead ion, thereby catalyzing the rA site of the substrate DNA, causing the cleaved substrate DNA to dissociate while releasing fluorescence. The fluorescence intensity is correlated with the lead ion concentration, and the fluorescence can be simultaneously detected by fluorescence quantitative PCR machine. Results The method had high specificity for detecting lead, the linear range was 0.001-0.1 mg/kg, the correlation coefficient r2 was 0.991, and the detection limit was 0.0008 mg/kg. Conclusion The method is simple, easy to use, low in energy consumption, and high in sensitivity, which is suitable for high-throughput determination of lead in large-volume samples. It is of great significance for the increasing demand for food inspection and testing and increasingly strict food safety regulatory requirements.