Biosensors: frontiers in rapid detection of COVID-19

Abstract

The rapid community-spread of novel human coronavirus 2019 (nCOVID19 or SARS-Cov2) and morbidity statistics has put forth an unprecedented urge for rapid diagnostics for quick and sensitive detection followed by contact tracing and containment strategies, especially when no vaccine or therapeutics are known. Currently, quantitative real-time polymerase chain reaction (qRT-PCR) is being used widely to detect COVID-19 from various types of biological specimens, which is time-consuming, labor-intensive and may not be rapidly deployable in remote or resource-limited settings. This might lead to hindrance in acquiring realistic data of infectivity and community spread of SARS-CoV-2 in the population. This review summarizes the existing status of current diagnostic methods, their possible limitations, and the advantages of biosensor-based diagnostics over the conventional ones for the detection of SARS-Cov-2. Novel biosensors used to detect RNA-viruses include CRISPR-Cas9 based paper strip, nucleic-acid based, aptamer-based, antigen-Au/Ag nanoparticles-based electrochemical biosensor, optical biosensor, and Surface Plasmon Resonance. These could be effective tools for rapid, authentic, portable, and more promising diagnosis in the current pandemic that has affected the world economies and humanity. Present challenges and future perspectives of developing robust biosensors devices for rapid, scalable, and sensitive detection and management of COVID-19 are presented in light of the test-test-test theme of the World Health Organization (WHO).

Keywords: Biosensors; COVID-19; Rapid detection; SARS-CoV-2.

Fig. 1

Schematic structure of SARS-Cov-2 and its possible targets for diagnosing

Fig. 2

Biosensors for SARS-CoV-2 virus detection. a CRISPR based nucleic acid (RNA) detection. RNA transcripts containing the target sequence (green) are recognized by RNA guided Cas endonuclease and CRISPR-RNA (Cr-RNA) carrying the complementary sequence. The formation of the Cas-crRNA-RNA-transcript tertiary complex switches on the ‘collateral cleavage’ activity, thereby dramatically applying the fluorescent signal in the presence of the target RNA. Q quencher, F fluorophore (Zuo et al. ; Broughton et al. 2020). b Schematic diagram of COVID-19 FET based biosensor operation. SARS-CoV-2 spike antibody is conjugated onto the graphene sheet via 1-pyrenebutyric acid N-hydroxy-succinimide ester, which is an interfacing molecule, as a probe linker (Seo et al. 2020). c The FTO electrode consist sensing area made up of AuNPs conjugated with nCOVID-19 Ab either by physisorption or electrostatic bonding (Mahari et al. 2020). d Surface Plasmon Resonance (SPR) based biosensor for COVID-19 detection. Activation of the AffiCoat surface, the nucleo-capsid protein of SARS-CoV-2 are bound to the SPR chip, and remaining activated sites were passivated with ethanolamine. e Schematic diagram of the 2D gold Nanoislands (AuNIs) functionalized with complementary thiol-cDNA ligands

Fig. 3

Schematic representation of possible biosensors for detecting SARS-CoV-2. a Aptamer based Bio-nanogate biosensor for virus spike protein-specific detection. b Electrochemical biosensor for detecting nucleic acids in the sample. c DhITACT-TR Chip for robust detection of target pathogen in a single-step injection of RNA extract

Fig. 4

The schematic diagram for biosensors for detection SARS-Cov-2 virus includes CRISPR-Cas based RNA detection; aptamer-Au NPs based viral spike protein detection; electrochemical-AuNPs based viral RNA detection; graphene-field effect transistor biosensor for virus detection, silicon nanowire-based viral spike protein detection; non-labeling plasmonic techniques such as Surface Plasmon Resonance (SPR), surface-enhanced Raman scattering (SERS) and quartz-crystal microbalance (QCM) based biosensor for COVID-19