A　new　optical　sensor　membrane　for　sensing　of　Hg2+　in　aqueous　solution　has　been　developed　by　using　(5,10,15,20-tetraphenylporphyrin,　H2tpp)　as　a　lipophilized　indicator,　which　was　dissolved　in　an　organically　modified　sol-gel.　The　method　for　preparation　of　this　organically　modified　sol-gel　membrane　and　its　characteristics　were　investigated　in　detail.　The　fluorescence　quenching　of　the　sol-gel　membrane　by　Hg2+　showed　a　linear　response　over　the　Hg2+　concentration　range　of　5.0　x　10(-6)　to　1.0　x　10(-4)　mol/l　with　a　detection　limit　of　3.6　x　10(-6)　mol/l,　and　the　good　stability,　reversibility,　long　lifetime　and　short　response　time　could　be　obtained.　(c)　2005　Elsevier　B.V.　All　rights　reserved.