中文摘要：

利用纳米金放大的方法,将修饰荧光团的信号DNA连接在纳米金表面,纳米金通过HBV-DNA与磁珠连接,1,4-二硫苏糖醇（DTT）可以替代信号DNA连接在纳米金表面,将荧光素标记的信号DNA释放于溶液中,测定溶液的荧光强度可以得到HBV-DNA的浓度。通过条件优化实验确定了最佳实验条件：生物素与亲和素最佳结合时间为25min,DNA的最佳杂交时间为15min。测定HBV-DNA的线性范围为3.0×10-13～1.2×10-12mol·L-1,线性相关系数r=0.991 4,检测限为2.18×10-14mol·L-1（S/N=3）。

英文摘要：

Using a highly ultrasensitive fluorescence-detection method based on gold nanoparticles and magnetic beads assisted by dithiothreitol（DTT） could detect the target DNA.The detection of HBV-DNA was achieved by monitoring fluorescence signals obtained from the adsorbed thiolated oligonucleotides modified with fluorophore which were liberated from the gold nanoparticle surface.The best reaction conditions were obtained through the study on the effect of different reaction time on the system＇s fluorescent intensity.The optimal reaction time of biotin and streptavidin was 25 min.15 min was chosen as the hybridization time of capture probes and target DNA.In the system of fluorescence spectroscopy based on gold nanoparticles,the HBV-DNA could be quantified in the range of 3.0 × 10-13—1.2 × 10-12 mol·L-1 and the detection limit was 2.18 × 10-14 mol·L-1（S/N=3）.