title: Recognition of glycoprotein peroxidase via Con A-carrying self-assembly layer on gold.
abstract: We have successfully fabricated a self-assembled layer of concanavalin A (Con A) on a gold surface for recognition of glycoproteins. The type IV Con A is covalently bound to 11-mercaptoundecanoic acid (MUA) on gold with a 2-(5-norbornene-2,3-dicarboximido)-1,1,3,3-tetramethyluronium tetrafluoroborate (TNTU) linkage. The binding interaction between glycoproteins and self-assembled Con A is studied using horseradish peroxidase (HRP) as a model glycoprotein. Voltammetric, electrochemical impedance studies, and photometric activity measurements show the presence of both specific and nonspecific bindings of HRP to the Con A interface. The specific binding is attributed to the Con A-sugar interaction where Con A selectively recognizes the glycosylation sites of HRP. The catalytic current of the HRP-loaded electrode, because of catalytic oxidation of thionine in the presence of hydrogen peroxide (H2O2), is found to be proportional to the HRP concentrations in the incubation solution. A linear correlation coefficient of 0.993 was obtained over a wide HRP concentration range of 12.5 microg/mL to 1 mg/mL. The approach described in this study provides a simple yet selective means to immobilize glycoproteins on a solid support. The specific binding achieved is desirable in biosensor fabrication, glycoprotein separation, recognition, and purification as well as in drug-releasing systems.
authors.affiliation: College of Chemistry and Chemical Engineering, Southeast University, Nanjing, PR China. liusq@seu.edu.cn
authors.forename: Songqin
authors.initials: S
authors.lastname: Liu
authors.forename: Kewei
authors.initials: K
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Du
authors.forename: Yueming
authors.initials: Y
authors.lastname: Sun
authors.forename: Lin
authors.initials: L
authors.lastname: He
mesh_terms: D003208:Concanavalin A / Q000737:chemistry*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D010544:Peroxidases / Q000737:chemistry*
chemical_list: D003208:Concanavalin A; D006046:Gold; D010544:Peroxidases