| The interaction between D-mannose and concanavalin(ConA) was always used as a model target for protein-carbohydrate interactions.A simple,sensitive electrochemical impedance spectroscopy(EIS) biosensor was herein reported for the detection of ConA based on neoglycoproteins.D-mannose was covalently attached to a carrier protein,bovine serum albumin(BSA) to generate multivalent neoglycoproteins by the Maillard reaction.The biosensor was designed by immobilizing the neoglycoproteins on the surface of glassy carbon electrode,whose structures were recognized by concanavalinA(ConA).Since the neoglycoconjugates were easily prepared,a large number of D-mannoses could format multivalent complexs with ConA.The biosensor was highly sensitive.The increase of the electron transfer resistance of the biosensor was in logarithmically direct proportion to the concentration of ConA in the range of 5.0×10-11-5.0×10-9 mol/L.The detection limit for ConA was 1.7×10-11 mol/L,with an affinity constant Ka of 2.6×106 L/mol.The method developed in this study may be a promising approach,and could be extended to the design of an EIS biosensor for highly sensitive and rapid detection of other desired carbohydrate-protein interactions. |