Noble　metal　nanoparticles　are　currently　of　great　interest　because　of　their　unique　optical　properties　and　potential　applications　in　disease　diagnostics　and　cancer　treatment.　In　the　present　work,　a　discovery　was　reported　that　dsDNA　with　terminal　thiols　at　its　two　ends　could　lie　easily　flat　onto　the　gold　nanoparticle　(GNP)　surface　rather　than　cross　linked　different　GNPs,　indicating　an　unique　self-assembly　behavior　of　newly-designed　molecules　on　GNPs.　This　could　intensively　stabilize　gold　nanoparticles　against　aggregation　even　at　a　high　salt　concentration.　On　the　basis　of　this　discovery,　a　novel　light-up　colorimetric　sensing　strategy　was　developed　for　the　detection　of　p53　gene　by　combining　with　the　cyclical　nucleic　acid　strand-displacement　polymerization　(CNDP).　For　the　described　colorimetric　system,　GNPs　require　no　any　surface　functionalization,　and　target　recognition　reaction　and　CNDP　amplification　could　be　conducted　under　the　optimized　conditions　to　achieve　a　high　efficiency.　The　high　detection　sensitivity　and　desirable　selectivity　are　achieved,　and　the　potential　practical　application　was　demonstrated.　Besides,　this　sensing　system　can　function　in　a　wide　range　of　salts,　making　it　a　suitable　platform　to　cooperate　with　many　biological　processes.　©　2014　Elsevier　B.V.