Label-Free and In Situ Glycophenotyping Using a Glycocalyx-Mimetic Electrochemical Transducer

Rapid glycophenotyping is often limited by biofouling, reliance on complex, multistep labeling, and poor access to living cell surfaces. Here, however, we introduce a glycocalyx-mimetic electrochemical interface that converts lectin-glycan binding into multiplex electrical signals. We coat gold electrodes with a self-assembled brush of lubricin (PRG4), whose densely O-glycosylated mucin domains present tumor-associated truncated O-glycans that serve as linkers to the lectins, our recognition elements. Embedding six lectins within lubricin enables orthogonal recognition of Gal-GalNAc-terminated oligosaccharides. In an electrochemical culture-plate format, the resulting sensor supports real-time, in situ glycophenotyping of melanoma cells, achieving quantitative agreement to a conventional, end point, lectin microarray. This glycocalyx-mimetic transducer thus enables the rapid, label-free screening of lectin-glycan interactions and the profiling of diagnostically relevant, tumor-associated glycans.