Carcinoembryonic　antigen　(CEA)　is　an　important　biomarker　in　cancer　diagnosis.　Here,　we　present　an　efficient,　selective　lateral-flow　immunoassay　(LFIA)　based　on　magnetic　nanoparticles　(MNPs)　for　in　situ　sensitive　and　accurate　point-of-care　detection　of　CEA.　Signal　amplification　mechanism　involved　linking　of　detection　MNPs　with　signal　MNPs　through　biotin-modified　single-stranded　DNA　(ssDNA)　and　streptavidin.　To　verify　the　effectiveness　of　this　modified　LFIA　system,　the　sensitivity　and　specificity　were　evaluated.　Sensitivity　evaluation　showed　a　broad　detection　range　of　0.25-1000　ng/ml　for　CEA　protein　by　the　modified　LFIA,　and　the　limit　of　detection　(LOD)　of　the　modified　LFIA　was　0.25　ng/ml,　thus　producing　significant　increase　in　detection　threshold　compared　with　the　traditional　LFIA.　The　modified　LFIA　could　selectively　recognize　CEA　in　presence　of　several　interfering　proteins.　In　addition,　this　newly　developed　assay　was　applied　for　quantitative　detection　of　CEA　in　human　serum　specimens　collected　from　10　randomly　selected　patients.　The　modified　LFIA　system　detected　minimum　0.27　ng/ml　of　CEA　concentration　in　serum　samples.　The　results　were　consistent　with　the　clinical　data　obtained　using　commercial　electrochemiluminescence　immunoassay　(ECLIA)　(p　＜　0.01).　In　conclusion,　the　MNPs　based　LFIA　system　not　only　demonstrated　enhanced　signal　to　noise　ratio,　it　also　detected　CEA　with　higher　sensitivity　and　selectivity,　and　thus　has　great　potential　to　be　commercially　applied　as　a　sensitive　tumor　marker　filtration　system.　(C)　2016　Elsevier　B.V.　All　rights　reserved.