A facile strategy for quantitative sensing of glycans on cell surface using organic electrochemical transistors

This work designed a facile sensing strategy for quantitation of glycans on cell surface using organic electrochemical transistors (OECTs). The sensing strategy was performed by covalently binding target cells on mercaptopropionic acid modified gate electrode for the recognition of horseradish peroxidase (HRP) labeled lectins to specific glycans on cell surface, which led to sensitive channel current signal responding to the captured HRP and thus the expression of cell surface glycans. The quantitation of glycans on cell surface was achieved by using glycan modified microspheres to simulate the cells, on which the amounts of glycans were detected with enzyme linked immunosorbent assay. The proposed sensing strategy had been used for the detection of mannose and galactose on HeLa cells with Concanavalin A and peanut agglutinin as the specific lectins, which showed 1.37 × 10⁸ mannose and 1.13 × 10⁸ galactose on each cell, respectively. By treating HeLa cells with exoglycosidases, the mannose and galactose expression levels showed the same changes as those detected with flow cytometric analysis, indicating the practical application of the OECT-based biosensor in cell surface glycan expression analysis.