Recent Progress in Lectin-Based Biosensors.

Baozhen Wang,Jun-Ichi Anzai

doi:10.3390/ma8125478

Abstract

This article reviews recent progress in the development of lectin-based biosensors used for the determination of glucose, pathogenic bacteria and toxins, cancer cells, and lectins. Lectin proteins have been widely used for the construction of optical and electrochemical biosensors by exploiting the specific binding affinity to carbohydrates. Among lectin proteins, concanavalin A (Con A) is most frequently used for this purpose as glucose- and mannose-selective lectin. Con A is useful for immobilizing enzymes including glucose oxidase (GOx) and horseradish peroxidase (HRP) on the surface of a solid support to construct glucose and hydrogen peroxide sensors, because these enzymes are covered with intrinsic hydrocarbon chains. Con A-modified electrodes can be used as biosensors sensitive to glucose, cancer cells, and pathogenic bacteria covered with hydrocarbon chains. The target substrates are selectively adsorbed to the surface of Con A-modified electrodes through strong affinity of Con A to hydrocarbon chains. A recent topic in the development of lectin-based biosensors is a successful use of nanomaterials, such as metal nanoparticles and carbon nanotubes, for amplifying output signals of the sensors. In addition, lectin-based biosensors are useful for studying glycan expression on living cells.

Highlights

Biosensors are fabricated by combining molecular recognition elements, such as enzymes and antibodies, and electrical or optical transducers
Bienzyme sensors consisting of glucose oxidase (GOx) and horseradish peroxidase (HRP) were prepared based on LbL deposition of concanavalin A (Con A) and enzymes on the surface of electrode and the electrochemical response to phenols, aromatic amines, and sulfides was studied [57,58]
The usefulness of the lectin-carbohydrate affinity for constructing biosensors is that any sugar-tagged proteins can be immobilized on the surface of electrochemical and optical transducers

Summary

Introduction

Biosensors are fabricated by combining molecular recognition elements, such as enzymes and antibodies, and electrical or optical transducers. A variety of protocols have been developed for immobilizing proteins on a solid surface, including irreversible adsorption through hydrophobic and electrostatic forces, chemical cross-linking with divalent reagents, entrapment in polymer networks, and covalent bonding [1,2,3] Another protocol for protein immobilization is to use binding proteins as molecular glue that adheres to enzymes and antibodies through biological interactions. LbL-deposited protein films have recently attracted much attention because of their potential applications to controlled release and biosensors [26,27,28] Another protocol relies on cross-linking of glycoproteins with Con A in the mixed solution to form a protein gel layer on the transducer surface (Figure 1c). Biosensors for the determination of glucose, pathogenic bacteria and toxins, cancer cells, and lectins are discussed

Glucose Sensors

Pathogenic Bacteria and Toxin Sensors

Findings

Conclusions