用于痕量己烯雌酚检测的DNA折纸表面增强拉曼散射信号探针的制备

Preparation of DNA origami surface-enhanced Raman scattering signal probe for trace diethylstilbestrol detection

目的制备具有表面增强拉曼散射效应的DNA折纸信号探针,应用于己烯雌酚的检测。方法M13mp18长链DNA,与适配体DNA链、Cy5信号分子标记DNA链等短链引物经两次退火,合成菱形DNA折纸。修饰了巯基DNA的金纳米粒子(gold nanoparticles,AuNPs)通过碱基互补配对,自组装在菱形DNA折纸特定位点,构建一种DNA折纸信号探针。通过琼脂糖凝胶电泳以及原子力显微镜分析DNA折纸信号探针合成效率的影响因素,对比不同波长激光下的DNA折纸信号探针增强效应,优化实验条件,对不同浓度的己烯雌酚进行检测。结果DNA折纸信号探针具有显著的表面增强拉曼散射效应,在785 nm激光波长下,己烯雌酚的最低检出浓度为0.05μg/L。结论本研究制备的DNA折纸信号探针可作为表面增强拉曼光谱的基底用于己烯雌酚的痕量检测,在食品安全领域具有良好的应用潜力。

Objective To prepare a DNA origami surface-enhanced Raman scattering probe for the detection of diethylstilbestrol.Methods M13mp18 single-stranded DNA and short strand primers,including aptamer DNA strand and Cy5 labeled molecular DNA strand,were annealed twice to synthesize rhombic DNA origami.Gold nanoparticles(AuNPs)modified with mercapto DNA self-assembled at specific sites of rhombic DNA origami through complementary base-pairing and constructed a DNA origami signal probe.The factors affecting the synthesis of the DNA origami signal probe were analyzed by agarose gel electrophoresis and atomic force microscopy,and theenhancement effects of the DNA origami signal probe under different laser wavelengths were analyzed.The experimental conditions were optimized,and then different concentrations of diethylstilbestrol were detected.Results The DNA origami signal probe had a significant surface-enhanced Raman scattering effect,and the minimum detection concentration of diethylstilbestrol at 785 nm laser wavelength was 0.05μg/L.Conclusion The DNA origami signal probe prepared in this study can be used as the basis of surface-enhanced Raman spectroscopy for trace determination of diethylstilbestrol,which has good application potential in the field of food safety.