A　simple　and　low-cost　DNA　sensing　platform　based　on　Pb2+-specific　DNAzyme-modified　microplate　was　successfully　developed　for　highly　sensitive　monitoring　of　lead　ion　(Pb2+,　one　kind　of　toxic　heavy　metal　ion)　in　the　environmental　samples　coupling　with　a　portable　personal　glucometer　(PGM)-based　detection　mode.　The　detection　cell　was　first　prepared　simply　by　means　of　immobilizing　the　DNAzyme　on　the　streptavidin-modified　microplate.　Gold　nanoparticle　labeled　with　single-stranded　DNA　and　invertase　(Enz-AuNP-DNA)　was　utilized　as　the　signal-transduction　tag　to　produce　PGM　substrate　(glucose).　Upon　addition　of　lead　ion　into　the　microplate,　the　substrate　strand　of　the　immobilized　DNAzyme　was　catalytically　cleaved　by　target　Pb2+,　and　the　newly　generated　single-strand　DNA　in　the　microplate　could　hybridize　again　with　the　single-stranded　DNA　on　the　Enz-AuNP-DNA.　Accompanying　with　the　Enz-AuNP-DNA,　the　carried　invertase　could　convert　sucrose　into　glucose.　The　as-produced　glucose　could　be　monitored　by　using　a　widely　accessible　PGM　for　in　situ　amplified　digital　readout.　Based　on　Enz-AuNP-DNA　amplification　strategy,　as　low　as　1.0　pM　Pb2+　could　be　detected　under　the　optimal　conditions.　Moreover,　the　methodology　also　showed　good　reproducibility　and　high　selectivity　toward　target　Pb2+　against　other　metal　ions　because　of　highly　specific　Pb2+-dependent　DNAzyme,　and　was　applicable　for　monitoring　Pb2+　in　the　naturally　contaminated　sewage　and　spiked　drinking　water　samples.　(C)　2015　Elsevier　B.V.　All　rights　reserved.