Electrochemical Biosensors for Pathogen Detection: An Updated Review

Abstract

Electrochemical biosensors are a family of biosensors that use an electrochemical transducer to perform their functions. In recent decades, many electrochemical biosensors have been created for pathogen detection. These biosensors for detecting infections have been comprehensively studied in terms of transduction elements, biorecognition components, and electrochemical methods. This review discusses the biorecognition components that may be used to identify pathogens. These include antibodies and aptamers. The integration of transducers and electrode changes in biosensor design is a major discussion topic. Pathogen detection methods can be categorized by sample preparation and secondary binding processes. Diagnostics in medicine, environmental monitoring, and biothreat detection can benefit from electrochemical biosensors to ensure food and water safety. Disposable and reusable biosensors for process monitoring, as well as multiplexed and conformal pathogen detection, are all included in this review. It is now possible to identify a wide range of diseases using biosensors that may be applied to food, bodily fluids, and even objects' surfaces. The sensitivity of optical techniques may be superior to electrochemical approaches, but optical methods are prohibitively expensive and challenging for most end users to utilize. On the other hand, electrochemical approaches are simpler to use, but their efficacy in identifying infections is still far from satisfactory.

Keywords: biosensors; electrochemical; medical diagnostics; pathogen detection; pathogen quantification.

Figure 1

Overview of the biosensor and its components.

Figure 2

The smart portable wireless potentiostat for Rapid Quantification of SARS-CoV-2 Spike Protein. Reprinted with permission from ref. [80].

Figure 3

Principle of detection of bacteria such as L. monocytogenes using a TiO2 nanowire bundle microelectrode-based impedance immunosensor. Reprinted with permission from ref. [60]. Copyright 2008, American Chemical Society.

Figure 4

(A) Shows an experimental method for detecting Influenza virus and 8 iso Prostaglandin F2α (PGF 2a) in exhaled breath condensate (EBC) samples using a silicon nanowire (SiNW) sensor device with and without magnetic concentration. The EBC samples were collected, diluted 100 times, and then flowed at a rate of 170 L/min to the sensor device. (B) SiNW sensor apparatus used in the sensing tests: (1) an optical image of the chip device; (2) a scanning electron microscopy (SEM) image of a single SiNW sensor; (3) an atomic force microscopy (AFM) image of a SiNW device modified with an anti-H3N2 virus antibody and infected with viruses; and (4) SEM photos of magnetic beads. (C) Bacteria found in indoor air and EBC samples taken from human participants with and without the flu (Influenza virus). Following culture, bacteria were found in the following samples: (1) EBC samples; (2) SEM images of the bacteria present in the samples; (3) indoor air samples; and (4) higher resolution SEM photographs of the bacteria present in the samples (2). (D) The use of quantitative PCR (qPCR) to identify bacteria in EBC samples obtained from flu patients and healthy individuals. Reproduced with permission from ref. [134]. Copyright 2012, American Chemical Society.

Figure 5

Schematic illustration of the stepwise preparation of anti-rotavirus self-assembled monolayers (SAM) immunosensor (BSA: Bovine Serum Albumin). Reprinted with permission from ref. [74]. Copyright 2016, John Wiley & Sons, Inc.

Figure 6

Schematic illustration of the electrochemical detection method used for the detection of Cryptosporidium parvum Oocysts. Self-assembling aptamer and primer hybrids were applied to a carbon electrode that had been screen-printed with gold nanoparticles (GNPs-SPCE). By using square wave voltammetry, the binding of the C. parvum oocyst to the immobilized aptamer increases the redox current. Reprinted with permission from ref. [168]. Copyright 2015, PLOS.