Electrochemical immunosensor for rapid and highly sensitive detection of SARS-CoV-2 antigen in the nasal sample

Abstract

A label-free electrochemical biosensing approach as an appropriate analysis technique for SARS-CoV-2 spike protein (SARS-CoV-2 S-protein) was investigated to facilitate the diagnosis of coronavirus in real samples. It is crucial to construct diagnostic features that can rapidly identify infected individuals to limit the spread of the virus and assign treatment choices. Therefore, a novel and selective method using SiO 2 @UiO-66 and a label-free electrochemical immunoassay for rapidly detecting spike protein. The development of innovative approaches for direct viral detection employing simplified and ideally reagent-free assays is a pressing and difficult topic. The absence of speedy and effective ways to diagnose viral diseases especially SARS-CoV-2 on demand has worsened the issue of combating the COVID-19 pandemic. The developed electrode illustrated a wide dynamic range of 100.0 fg mL −1 to 10.0 ng mL −1 with low limit detection. Therefore, the as-fabricated electrochemical SARS-CoV-2 S-protein sensor suggests an appropriate perspective in the point-of-care system, within 5.0 min, in nasal samples with satisfactory recovery.

Electrochemical immunosensors using electrodeposited gold nanostructures for detecting the S proteins from SARS-CoV and SARS-CoV-2

“…The electrodes were then rinsed using MES buffer (100 mmol L −1 , pH 6.0) and dried using N 2 . Twenty microliters of 1 µg mL −1 anti-protein S antibodies (PBS, 0.1 mol L −1 , pH 7.0) was added to the electrode for 1 h. The antibody's concentration applied is within the concentration range reported in the literature for the manufacture of immunosensors used for SARS-CoV-2 detection, which range from 1 ng L −1 to 100 µg L −1 [31,32,[35][36][37][38][39][40]. Electrodes were washed using PBS (0.1 mol L −1 , pH 7.0) and dried with an N 2 gas stream.…”

“…Electrodes were washed using PBS (0.1 mol L −1 , pH 7.0) and dried with an N 2 gas stream. Finally, a BSA solution (1% w/v, 30 min, 0.1 mol L −1 PBS, pH 7.0) was incubated on the electrode for 30 min for blocking the bioreceptor layer [33,[35][36][37]. After washing the modified electrode with PBS (0.1 mol L −1 , pH 7.0) and drying it with N 2 , the biosensor was ready for use.…”

Nanobody-based label-free photoelectrochemical immunoassay for highly sensitive detection of SARS-CoV-2 spike protein

“… Biosensor Method LOD (fg mL −1 ) Advantages Disadvantages Ref. Opto-microfluidic sensor Microfluidic device with Au nanospikes 8.0 × 10 4 Compact device and fast detection (30 min) High operator requirements [ 45 ] Phononic sensor Antibody-coupled graphene 1.0 Real-time detection and low fabrication cost Relatively expensive spectrometer [ 46 ] FET sensor Graphene-based device 1.0 Real-time detection and quick analysis High fabrication and testing cost [ 11 ] FET sensor Semiconducting single-walled carbon nanotube with antibody 0.55 Rapid detection (5 min) and high sensitivity High fabrication and testing cost [ 47 ] Electrochemical immunosensor Label-free detection 1.0 × 10 2 Low immunological response time (5 min) and easy preparation Low stability [ 48 ] Electrochemical immunosensor Magnetic bead-based screen-printed carbon electrodes 1.9 × 10 7 Rapid analysis (30 min) and portable instrument Low stability [ 16 ] PEC immunosensor Label-free detection 5.0 Simple operation, rapid response (30 min) and low cost Difficult to real-time detection This work …”

An electrochemical membrane-based aptasensor for detection of severe acute respiratory syndrome coronavirus-2 receptor-binding domain

“…The electrochemical aptamer-based sensors (aptasensors) and immune-based sensors (immunosensors) are widely used biosensors for the detection of the biomarkers related to SARS-CoV-2 [25] , [26] . The electrochemical aptasensors [27] , [28] , [29] have several advantages over the immunosensors [30] , [31] , [32] including low price, high stability, ease of fabrication, and in some cases better specificity and affinity.…”