A lectin-immunoassay detecting the fucosylation of PSA is proposed. Assay sensitivity was improved by coupling the AAL lectin onto Eu3 +-nanoparticles. Low affinity of lectin was strengthened by coupling AAL on nanoparticles. The lectin-immunnoassay could differentiate between PSA from different origin. Increased PSA fucosylation in PCa tissue compared to benign tissue was observed.