The Role of Electrochemical Immunosensors in Clinical Analysis

Abstract

An immunosensor is a kind of affinity biosensor based on interactions between an antigen and specific antigen immobilized on a transducer surface. Immunosensors possess high selectivity and sensitivity due to the specific binding between antibody and corresponding antigen, making them a suitable platform for several applications especially in the medical and bioanalysis fields. Electrochemical immunosensors rely on the measurements of an electrical signal recorded by an electrochemical transducer and can be classed as amperometric, potentiometric, conductometric, or impedimetric depending on the signal type. Among the immunosensors, electrochemical immunosensors have been more perfected due to their simplicity and, especially their ability to be portable, and for in situ or automated detection. This review addresses the potential of immunosensors destined for application in clinical analysis, especially cancer biomarker diagnosis. The emphasis is on the approaches used to fabricate electrochemical immunosensors. A general overview of recent applications of the developed electrochemical immunosensors in the clinical approach is described.

Keywords: biomarker; clinical analysis; electrochemistry; immunosensors; label free; labeled.

Figure 1

Schematic diagram of the electrochemical biosensor array. The bioassay is carried out using the working electrodes of the array as transducers and in situ electrochemical detection of QDs. Reprinted with Permission [22].

Figure 2

Schematic representation of (A) competitive and (B) non-competitive immunoassay formats. Reprinted with Permission [35].

Figure 3

The schematic illustration of the dual mode competitive electrochemical immunosensor. Reprinted with Permission [38].

Figure 4

Schematic representation of Fullerene-Functionalized Carbon Nanotubes/Ionic Liquid based label-free electrochemical immunosensor. Reprinted with Permission [75].

Figure 5

The schematic illustration of the sandwich-type electrochemical immunosensor and the preparation procedure of Au@N-GQDs NPs and Au@Ag-Cu₂O/Ab₂ Reprinted with Permission [82].