We　have　proposed　a　signal　dual-amplification　electrochemiluminescence　(ECL)　strategy　based　on　tris(2,2′-bipyridyl)ruthenium(II)　(Ru(bpy)32+)　as　chromophores　confined　with　three-dimensional　(3D)　zinc　oxalate　metal−organic　frameworks　(Ru(bpy)32+@MOFs)　for　the　detection　of　miRNA-21.　The　three-dimensional　chromophore　connectivity　in　zinc　oxalate　MOFs　provided　a　network　among　Ru(bpy)32+　units,　shielding　the　chromophores　from　solvent　molecules　and　resulting　in　high　Ru(II)　complex　emission　efficiency.　Additionally,　we　discovered　that　magnetic　beads　(MBs)　used　as　carrier　for　enriched　signals　contribute　to　enhanced　ECL　intensity　of　the　chromophore.　To　evaluate　its　clinical　application,　we　applied　this　method　to　determine　the　concentration　of　miRNA-21　solutions　ranging　from　1.56　to　100　nM,　obtaining　a　calibration　curve　of　ECL　intensity　versus　logarithm　of　concentration　(logC)　of　miRNA-21　with　a　high　correlation　coefficient.　This　work　demonstrates　the　construction　of　a　signal　amplification　strategy　ECL　biosensor　for　miRNA　using　Ru(bpy)32+@MOF　systems　and　its　application　in　ECL　detection　for　analyte　methodology.　©　2023　Elsevier　B.V.