Interactions between lectin-modified nanoparticles and various glycoproteins were investigated for development of effective nanoagents for therapy and diagnostics. We screened a variety of lectin-glycoprotein pairs both in cell-free mode and in vitro in human cell culture to create a number of highly specific nanoparticle-lectin conjugates. We showed that the obtained conjugates can be successfully used as biomarker-specific agents for specific cell visualization in biomedical diagnostics.