Here,　we　present　a　dual　amplification　strategy　based　on　a　duplex-specific　nuclease　and　a　hybridization　chain　reaction,　which　has　been　designed　for　the　highly　sensitive　detection　of　miRNAs.　In　the　first　step,　a　loop　amplification　strategy　based　on　a　duplex-specific　nuclease　was　employed　to　obtain　a　large　number　of　ssDNA　reporters　that　then　act　as　initiators　to　trigger　the　next　amplification　step.　The　second　step　involves　a　hybridization　chain　reaction　based　on　two　hairpin　DNAs　denoted　as　H-1　and　H-2.　Doxorubicin-CdTe　quantum　dots,　which　function　as　detecting　indicators　that　intercalated　into　the　hybridization　chain　reaction　products,　lead　to　significantly　amplified　electrochemiluminescence　signal　readout.　This　dual　amplification　strategy　enabled　the　sensitive　detection　of　let-7d　from　10　aM　to　10　nM　with　a　detection　limit　of　10　aM,　and　offered　an　excellent　capacity　to　discriminate　between　microRNA　family　members.　This　assay　therefore　offers　great　potential　applications　in　biomedical　research　and　early　clinical　diagnosis.　(C)　2017　Elsevier　B.V.　All　rights　reserved.