A　paper-based　visual　fluorescence　immunoassay　is　presented　for　the　detection　of　matrix　metalloproteinase-7　(MMP7)　that　is　related　to　renal　cancer.　The　method　is　based　on　the　distance-dependent　fluorescence　quenching　of　CdTe　quantum　dots　(QDs)　on　a　nitrocellulose　membrane　by　Ag+　following　a　sandwich-type　immunoreaction　on　microtiter　wells　using　silver　nanoparticle　(AgNP)-labeled　secondary　antibody-　and　primary　antibody-coated　microtiter　wells.　The　silver　nanoparticles　captured　in　the　well　are　dissolved　with　HNO3,　while　the　quenching　effect　of　QDs　is　based　on　silver　ion-exchange　reaction　under　365-nm　excitation　light　irradiation.　Increasing　concentration　of　released　Ag+,　thus　higher　concentration　of　the　protein,　leads　to　an　increased　distance　of　quenching　on　the　nitrocellulose　membrane.　The　paper-based　immunoassay　by　combination　of　AgNP-assisted　ion-exchange　reaction　with　QD　gives　good　distance-dependent　responses　and　allows　the　detection　of　MMP7　at　a　concentration　as　low　as　7.3　pg　mL(-1).　The　coefficients　of　variation　are　less　than　6.9%　and　12.4%　for　intra-assay　and　inter-assay,　respectively.　High　specificity　and　long-term　stability　are　achieved　during　the　assay.　Importantly,　the　testing　of　human　serum　samples　using　our　strategy　shows　well-matched　results　with　commercial　human　MMP7　ELISA