A　novel　portable　chemical　sensor　is　developed　in　combination　of　the　personal　glucose　meters　(PGM)　with　click　chemistry　for　sensitive　and　selective　determination　of　histidine.　Invertase-labeled　alkynyl-DNA　can　be　modified　onto　the　surfaces　of　Streptavidin　Magnespheres　Paramagnetic　Particles　(PMPs)　through　copper(I)　catalyzed　azide-alkyne　cycloaddition　(CuAAC)　reaction　and　formed　invertase-functionalized　PMPs,　which　can　be　separated　easily.　The　presence　of　invertase　can　convert　sucrose　to　glucose　and　can　be　monitored　by　the　PGM　easily.　The　presence　of　histidine　can　inhibit　the　CuAAC,　so　the　read-out　signal　of　PGM　decreased.　The　difference　in　signals　from　the　PGM　before　and　after　addition　of　histidine　has　a　good　linear　correlation　with　the　logarithm　of　the　histidine　concentrations　in　the　range　of　0.01　similar　to　100　mu　M　with　a　detection　limit　of　3.4　nM,　which　is　lower　than　those　of　many　other　chemical　sensors.　Moreover,　the　assay　of　histidine　in　milk　samples　is　demonstrated　with　satisfactory　results.　(C)　2013　Elsevier　B.V.　All　rights　reserved.