A　versatile　enzyme-free　deoxyribonucleic　acid　(DNA)　detection　method　based　on　hybridization　chain　reaction　(HCR)　and　fluorescence　resonance　energy　transfer　(FRET)　was　developed.　Hairpin　H1　and　H2　are　labelled　with　carboxyfluorescein　(FAM)　as　the　donor　and　tetramethylrhodamine　(TAMRA)　as　the　acceptor,　respectively.　In　the　presence　of　target　DNA,　long　nicked　dsDNA　nanowires　are　self-assembled　through　HCR　process.　The　donor　and　the　acceptor　are　brought　in　close　proximity,　resulting　in　a　FRET　process　between　them.　The　ratio　of　fluorescent　intensities　of　the　acceptor　and　donor　can　be　used　to　quantitatively　detect　the　target　DNA　with　a　limit　of　detection　0.7　nmol　L-1.　This　proposed　method　was　applied　to　detect　DNA　in　biologic　samples　with　satisfactory　results.　(C)　2016　Elsevier　B.V.　All　rights　reserved.