Impedance-derived electrochemical capacitance spectroscopy for the evaluation of lectin–glycoprotein binding affinity

• Published in: Biosensors & bioelectronics 2014-12, Vol.62, p.102-105
• Main Authors: Santos, Adriano, Carvalho, Fernanda C., Roque-Barreira, Maria-Cristina, Bueno, Paulo R.
• Format: Article
• Language: English
• Subjects: Affinity; ArtinM; Artocarpus - chemistry; Binding; Binding affinity constant; Biological and medical sciences; Biosensing Techniques; Biotechnology; Capacitance; Constants; Dielectric Spectroscopy; Electric Impedance; Ferrocenes; Fundamental and applied biological sciences. Psychology; Glycoproteins - analysis; Glycoproteins - metabolism; Horseradish Peroxidase - analysis; Horseradish Peroxidase - metabolism; HRP; Immobilized Proteins - isolation & purification; Immobilized Proteins - metabolism; Impedance-derived electrochemical capacitance spectroscopy; Langmuir isotherm; Lectins; Lectins - isolation & purification; Lectins - metabolism; Models, Molecular; Protein Binding; Spectroscopy
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2014.06.034

Characterization of lectin–carbohydrate binding using label-free methods such as impedance-derived electrochemical capacitance spectroscopy (ECS) is desirable to evaluate specific interactions, for example, ArtinM lectin and horseradish peroxidase (HRP) glycoprotein, used here as a model for protein–carbohydrate binding affinity. An electroactive molecular film comprising alkyl ferrocene as a redox probe and ArtinM as a carbohydrate receptive center to target HRP was successfully used to determine the binding affinity between ArtinM and HRP. The redox capacitance, a transducer signal associated with the alkyl ferrocene centers, was obtained by ECS and used in the Langmuir adsorption model to obtain the affinity constant (1.6±0.6)×108Lmol−1. The results shown herein suggest the feasibility of ECS application for lectin glycoarray characterization. •Immobilization of the ArtinM on SAM containing tethered probe redox.•Nanomolar range limit of detection for HRP protein.•Ideal conditions to apply Langmuir isotherm model using ECS.•Binding affinity constant determination by ECS approach.•ECS established as a promising platform for lectin glycoarray characterization.