A novel solid-state electrochemiluminescence (ECL) aptasensor based on target-induced aptamer displacement for highly sensitive detection of lysozyme (Lys) was developed successfully using Ru(bpy)32+-Silica@Poly-L-lysine-Au (Ru-Si@PLL-Au) nanocomposites labeling as enhancer,in which gold colloids (Au NPs) were doped on the surface of Ru-Silica (Ru(bpy)32+-doped Silica) using poly-L-lysine (PLL) as a bridging agent.