Using　fluorescently　labeled　DNA　oligonucleotides　and　nanomaterials　for　developing　biosensors　has　been　extensively　reported　for　gold　nanoparticles　(AuNPs)　and　graphene　oxide　(GO)　among　others.　These　materials　have　vastly　different　affinities　and　mechanisms　for　interacting　with　DNA,　and　their　analytical　performance　is　likely　to　be　different.　In　this　work,　we　used　several　DNA　sequences　and,　respectively,　adsorbed　them　on　AuNPs　and　GO　to　quench　fluorescence.　Different　from　previous　work,　we　used　KCN　to　fully　dissolve　the　AuNPs　to　calculate　the　percentage　of　the　desorbed　DNA　due　to　the　complementary　DNA　(cDNA)　and　aptamer　target.　The　desorbed　probe　DNA　from　the　AuNPs　was　less　than　5%　for　all　of　the　targets　including　DNA,　adenosine,　Hg2+,　and　lysozyme,　indicating　a　very　strong　DNA　adsorption　affinity.　Desorption　of　DNA　was　achieved　by　adding　HEPES　buffer,　NaCl,　and　As(III),　but　such　desorption　was　attributed　to　the　adsorption　of　these　molecules　or　ions　by　the　AuNPs　instead　of　their　interaction　with　the　adsorbed　DNA.　For　GO,　more　probes　desorbed　with　addition　of　target　analytes　but　so　did　nonspecific　desorption　by　random　DNA　and　proteins.　In　summary,　AuNPs　are　unlikely　to　be　a　good　surface　for　developing　biosensors　relying　solely　on　the　desorption　of　probe　DNA,　while　for　GO　the　main　problem　is　nonspecific　desorption.　©　2019　American　Chemical　Society.