The　detection　of　biomarkers　is　of　crucial　importance　in　reducing　the　morbidity　and　mortality　of　complex　diseases.　Thus,　there　is　a　great　desire　to　develop　highly　efficient　and　simple　sensing　methods　to　fulfill　the　different　diagnostic　and　therapeutic　purposes.　Herein,　using　tumor　suppressor　p53　gene　as　model　target　DNA,　we　developed　a　novel　palindromic　fragment-incorporated　molecular　beacon　(P-MB)　that　can　perform　multiple　functions,　including　recognition　element,　signal　reporter,　polymerization　template　and　primer.　Upon　specific　hybridization　with　target　DNA,　P-MBs　can　interact　with　each　other　and　are　extended　by　polymerase　without　any　additional　probes.　As　a　result,　hybridized　targets　are　peeled　off　from　P-MBs　and　initiate　the　next　round　of　reactions,　leading　to　the　unique　strand　displacement　amplification　(SDA).　The　newly-proposed　enzymatic　amplification　displays　the　detection　limit　as　low　as　100　pM　and　excellent　selectivity　in　distinguishing　single-base　mutation　with　the　linear　response　range　from　100　pM　to　75　nM.　This　is　the　simplest　SDA　sensing　system　so　far　because　of　only　involving　one　type　of　DNA　probe.　This　impressive　sensing　paradigm　is　expected　to　provide　new　insight　into　developing　new-type　of　DNA　probes　that　hold　tremendous　potential　with　important　applications　in　molecular　biology　research　and　clinical　diagnosis.