中文摘要：

目的构建用于检测细菌、病毒等病原体DNA的生物素-亲和素纳米颗粒信号放大载体。方法设计并合成两端和一端标记生物素的寡核苷酸探针（2B／1B—DNA），与抗生蛋白链菌素葡聚糖（Poly—STV）通过生物素与亲和素作用，偶联形成大分子纳米网状颗粒，并筛选最佳探针类型及其长度、2B—DNA和Poly—STV的浓度及比例和反应条件。结果2B—DNA和Poly—STV形成纳米颗粒信号放大载体的最佳浓度分别为1μmol／L和5μmol／L，最佳浓度比为1：5，2B-DNA长度为60bp，缓冲液为Buffer B，反应条件为55℃，800r／min，20min。结论已成功构建了生物素-亲和素大分子纳米颗粒，可作为DNA检测信号放大技术的备选载体。

英文摘要：

Objective To construct a biotin-streptavidin-DNA nanoparticle signal amplification carrier for assay of DNA in pathogens such as virus and bacterium. Methods Mono- and bis-biotinylated oligonucleotide probes （1B/2B-DNA） were designed and synthesized, then coupled to streptavidin-labeled dextran （Poly-STV） through the interaction of biotin and streptavidin to construct a macromolecular nanoparticle signal amplification carrier. The kind and length of probe, the concentrations of 2B-DNA and Poly- STV, the ratio of 2B-DNA to Poly-STV as well as reaction condition were optimized. Results The optimal concentrations of 2B-DNA and Poly-STV for construction of the carrier were 1 and 5 μmol / L respectively, the optimal ratio of 2B-DNA to Poly-STV was 1 ： 5, the optimal length of 2B-DNA was 60 bp, the optimal reaction condition was 55℃, 800 r/min for 20 min. Conclusion The biotin- streptavidin-macromolecular nanoparticles were successfully constructed, which might be used as a candidate cartier for DNA signal amplification detection technology.