A　novel　paper　electrode-based　flexible　pressure　sensor　modified　with　multiwalled　carbon　nanotubes　was　designed　for　point-of-care　(POC)　immunoassay　of　carcinoembryonic　antigen　(CEA)　with　digital　multimeter　readout.　The　portable　POC　testing　device　consisted　of　flexible　pressure　sensor　equipped　with　a　paper　electrode　and　connected　through　syringe　tubing　to　a　single-break　microplate.　The　immunoreaction　was　initially　carried　out　on　the　microplate　with　a　sandwich-type　assay　format　using　platinum　nanozyme-labeled　secondary　antibody　for　the　gas　generation.　Upon　addition　of　hydrogen　peroxide　(H2O2),　platinum　nanozyme　(catalase-like　mimic)　reduced　it　into　hydrogen　oxide　and　oxygen　(O-2).　The　overflowing　oxygen　gas　increased　the　pressure　of　the　multiwalled　carbon　nanotube-functionalized　paper　electrode　in　a　homemade　pressure-tight　system,　and　the　increased　pressure　could　be　readily　monitored　using　the　paper　electrode-based　flexible　pressure-tight　sensor　with　a　digital　multimeter　readout.　The　detectable　signal　mainly　derived　from　the　resistance　change　of　pressure　sensor　because　of　its　deformation　with　the　assistance　of　the　as-generated　gas,　and　the　shift　in　the　resistance　could　be　allowed　to　detect　the　gas　pressure　even　as　low　as　80　Pa.　Under　optimum　conditions,　pressure　sensor-based　immunoassay　exhibited　good　resistance　responses　toward　target　CEA　within　a　linear　range　of　0.5-60　ng/mL　at　a　detection　limit　of　167　pg/mL.　Moreover,　our　strategy　provided　acceptable　reproducibility,　precision,　high　specificity,　and　good　accordance　with　the　commercial　CEA　ELISA　kit　for　detecting　human　serum　specimens.