A　novel　flow-through　microfluidic　device　based　on　a　magneto-controlled　graphene　sensing　platform　was　designed　for　homogeneous　electronic　monitoring　of　pyrophosphatase　(PPase)　activity;　enzymatic　hydrolysate-induced　release　of　inorganic　copper　ion　(Cu2+)　from　the　Cu2+-coordinated　pyrophosphate　ions　(Cu2+-PPi)　complex　was　assessed　to　determine　enzyme　activity.　Magnetic　graphene　nanosheets　(MGNS)　functionalized　with　negatively　charged　Nafion　were　synthesized　by　using　the　wet-chemistry　method.　The　Cu2+-PPi　complexes　were　prepared　on　the　basis　of　the　coordination　reaction　between　copper　ion　and　inorganic　pyrophosphate　ions.　Upon　target　PPase　introduction　into　the　detection　system,　the　analyte　initially　hydrolyzed　pyrophosphate　ions　into　phosphate　ions　and　released　the　electroactive　copper　ions　from　Cu2+-PPi　complexes.　The　released　copper　ions　could　be　readily　captured　through　the　negatively　charged　Nafion　on　the　magnetic　graphene　nanosheets,　which　could　be　quantitatively　monitored　by　using　the　stripping　voltammetry　on　the　flow-through　detection　cell　with　an　external　magnet.　Under　optimal　conditions,　the　obtained　electrochemical　signal　exhibited　a　high　dependence　on　PPase　activity　within　a　dynamic　range　from　0.1　to　20　mU　mL(-1)　and　allowed　the　detection　at　a　concentration　as　low　as　0.05　mU　mL(-1).　Coefficients　of　variation　for　reproducibility　of　the　intra-assay　and　interassay　were　below　7.6　and　9.8%,　respectively.　The　inhibition　efficiency　of　sodium　fluoride　(NaF)　also　received　good　results　in　pyrophosphatase　inhibitor　screening　research.　In　addition,　the　methodology　afforded　good　specificity　and　selectivity,　simplification,　and　low　cost　without　the　need　of　sample　separations　and　multiple　washing　steps,　thus　representing　a　user-friendly　protocol　for　practical　utilization　in　a　quantitative　PPase　activity.