This study describes the development and characterization of a novel dendritic signal amplification strategy. It relies on the use of two different Ru(bpy)₃²⁺-doped silica nanoparticles (Probe_1,2RSNP and Probe_2cRSNP) coated with complementary DNAs, which can be simply and conveniently self-assembled to build sandwich-type dendritic architectures on a gold grid. The performance of this dendritic amplification route was demonstrated in conjunction with the electrogenerated chemiluminescent (ECL) detection of the target DNA. Compared to normal amplification, dendritic amplification allowed a 5-fold enhancement of the ECL signals. The higher sensitivity allowed by the dendritic amplification route was attributed to the hybridization between the DNA (Probe₂DNA) on Probe_1,2RSNP (normal amplification) and the complementary DNA (Probe_2c DNA) on the additional Probe_2cRSNP. As low as 1 fM of 22-bp-long target DNA was clearly detected. The experimental results demonstrated that the ECL intensity achieved through dendritic amplification showed a good linear relationship with the concentration of the target DNA over a wide linear range (10 fM∼10 pM).