Titanate　nanotubes　(TNTs)　have　some　unique　and　seductive　properties,　such　as　good　biocompatibility.　negative　charge　after　treating　with　weak　bases　and　supply　of　special　reaction　vessel　for　analyte　clue　to　their　hydroxyls　and　multilayered　structures.　Herein.　titanate　nanotubes　were　firstly　self-assembled　on　the　chitosan　(CHIT)　membrane　modified　electrode.　Then　thionine,　as　a　model　electrochemical　probe,　was　firmly　immobilized　onto　the　titanate　nanotubes　(TNTs)-based　sensing　interface.　This　strategy　provided　a　new　route　to　immobilize　the　redox　mediator　onto　the　sensing　interface.　Based　on　which.　trichloroacetic　acid　(TCA)　was　found　to　be　able　to　accelerate　the　electron　transmission　rate　and　improve　the　electrochemical　behavior　of　thionine.　Therefore,　a　wide　linear　range　for　the　detection　of　TCA　was　estimated　to　be　from　6　mu　M　to　1.5　mM　with　high　sensitivity　and　good　selectivity.　(C)　2010　Elsevier　B.V.　All　rights　reserved.