The　preparative-scale　separation　of　chiral　compounds　is　vitally　important　for　the　pharmaceutical　industry　and　related　fields.　Herein　we　report　a　simple　approach　for　rapid　preparative　separation　of　enantiomers　using　functional　nucleic　acids　modified　gold　nanoparticles　(AuNPs).　The　separation　of　(DL)-tryptophan　((DL)-Trp)　is　demonstrated　as　an　example　to　show　the　feasibility　of　the　approach.　AuNPs　modified　with　enantioselective　aptamers　were　added　into　a　racemic　mixture　of　(DL)-Trp.　The　aptamer-specific　enantiomer　((L)-Trp)　binds　to　the　AuNPs　surface　through　aptamer-(L)-Trp　interaction.　The　separation　of　(DL)-Trp　is　then　simply　accomplished　by　centrifugation:　the　precipitate　containing　(L)-Trp　bounded　AuNPs　is　separated　from　the　solution,　while　the　(D)-Trp　remains　in　the　supernatant.　The　precipitate　is　then　redispersed　in　water.　The　aptamer　is　denatured　under　95　degrees　C　and　a　second　centrifugation　is　then　performed,　resulting　in　the　separation　of　AuNPs　and　(L)-Trp.　The　supernatant　is　finally　collected　to　obtain　pure　(L)-Trp　in　water.　The　results　show　that　the　racemic　mixture　of　(DL)-Trp　is　completely　separated　into　(D)-Trp　and　(L)-Trp,　respectively,　after　5　rounds　of　repeated　addition　of　fresh　aptamer-modified　AuNPs　to　the　(DL)-Trp　mixture　solution.　Additionally,　the　aptamer-modified　AuNPs　can　be　repeatedly　used　for　at　least　eight　times　without　significant　loss　of　its　binding　ability　because　the　aptamer　can　be　easily　denatured　and　renatured　in　relatively　mild　conditions.　The　proposed　approach　could　be　scaled　up　and　extended　to　the　separation　of　other　enantiomers　by　the　adoption　of　other　enantioselective　aptamers.　Chirality　25:751-756,　2013.　(c)　2013　Wiley　Periodicals,　Inc.