基于核酸适配体的胶体金比色法检测奶粉中的乳铁蛋白

Determination of lactoferrin in milk powder by colloidal gold colorimetry based on nucleic acid aptamer

目的 建立一种基于核酸适配体胶体金(colloidal gold,AuNPs)比色法检测奶粉中乳铁蛋白(lactoferrin, LF)的方法。方法 以无标记的LF适配体为生物识别元件, AuNPs为信号分子,利用AuNPs的光学特性构建一种可定性和定量检测LF的比色适配体传感器。结果 在最优条件下,20min内即可完成检测,在5~75 nmol/L浓度范围内具有良好线性关系,相关系数(r;)为0.998,检出限为3.6 nmol/L,特异性较好,并且在基质标准曲线中也表现出较好的线性关系(r;=0.987)。结论 该方法操作简单,分析快速,安全环保,灵敏度较高,有望应用于奶粉中LF的检测。

Objective To establish a colorimetric method for the detection of lactoferrin(LF) in milk powder based on aptamer colloidal gold(AuNPs). Methods Using unlabeled LF adaptor as biometric element and AuNPs as signal molecule, a colorimetric adaptor sensor for qualitative and quantitative detection of LF was constructed based on the optical properties of AuNPs. Results Under the optimal conditions, the assay could be completed within 20 min. It had a good linear relationship in concentration range of 5-75 nmol/L, the correlation coefficient(r~2) was 0.998, and the limit of detection was 3.6 nmol/L. The specificity was good and it also showed a good linear relationship in the matrix standard curve(r~2=0.987). Conclusion The method is simple, rapid, safe, environmentally friendly and sensitive, and is expected to be used for the determination of LF in milk powder.