Firstly, thiol probes and fluorescent probes annealing hybrid, then the hybrid duplexes marked on gold nanoparticles, narrowing the distance between gold nanoparticles and FAM. Due to the quenching effect of gold nanoparticles, the fluorescence intensity of FAM greatly reduced. 巯基探针和荧光探针先退火杂交,然后将杂交双链通标记在纳米金颗粒上,这样拉近了纳米金与荧光基团FAM之间的距离,由于纳米金的猝灭作用,致使FAM的荧光强度大大降低。