ABSTRACT
Electrochemical biosensors for determining wildtype and omicron variant of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) nucleocapsid antigen in nasopharyngeal swab samples were produced by using functionalised graphene oxide and the wildtype and omicron types of SARS-CoV-2 nucleocapsid antibody modified glassy carbon electrodes. The developed biosensors characterised by cyclic voltammetry, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy were able to detect 0.76 and 0.24 ag/mL of the wildtype and omicron SARS-CoV-2 nucleocapsid antigen protein in linear ranges varied from 1 ag/mL to 100 fg/mL and from 1 ag/mL to 10 fg/mL, respectively. The performance of both biosensors produced was compared in nasopharyngeal swab samples containing the wildtype and omicron variant of the SARS-CoV-2, and it was evaluated whether they could be used interchangeably.
Subject(s)
Biosensing Techniques , COVID-19 , Antibodies, Viral , COVID-19/diagnosis , Electrochemical Techniques , Humans , Nucleocapsid Proteins , SARS-CoV-2/geneticsABSTRACT
A portable and low-cost electrochemical immunosensor platform is developed for rapid (13 min) and accurate quantification of SARS-CoV-2 serum antibodies (10.1 ng/mL − 60 µg/mL for IgG and 1.64 ng/mL − 50 µg/mL for IgM). No obvious cross-reactivity with other interference proteins was observed. Stable performance of the immunosensor within 24-week storage at room temperature was achieved. The practical use of the immunosensor was demonstrated using real patient samples. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.
ABSTRACT
Localized surface plasmon resonance of Au nanodots array are very sensitive and resonance field disturbance due to 100 nm sized SARS-CoV-2 virus can be detected via resonance wavelength shift. We have proposed Au nanodots (100 nm diameter and 200 nm pitch) array plasmonic biosensing platform for SARS-CoV-2 virus detection. © 2022 The Author(s).
ABSTRACT
The outbreak of the emerging SARS-CoV-2 virus has highlighted the challenges of detecting viral infections, especially in resource-limited settings. The SARS-CoV-2 virus transmission chain is interrupted when screening and diagnosis can be performed on a large scale by identifying asymptomatic or moderately symptomatic patients. Diagnosis of COVID-19 with reverse transcription polymerase chain reaction (RT-PCR) has been limited due to inadequate access to complex, expensive equipment and reagents, which has impeded efforts to reduce the spread of virus transmission. Recently, the development of several diagnostic platforms based on the CRISPR-Cas system has reduced the dependence on RT-PCR. The first CRISPR-based diagnostic test for SARS-CoV-2 was recently approved by the U.S. Food and Drug Administration. The biosensing systems have several important features that make them suitable for point-of-care tests, including the speed of design and synthesis of each platform in less than a few days, an assay time of 1-2 h, and the cost of materials and reagents less than one dollar per test. The HUDSON-SHERLOCK and STOPCovid biosensing systems, as field-deployable and rapid diagnostic tests, can detect low-copy viruses in body fluids without nucleic acid extraction and with minimal equipment. In addition, Cas13-based treatment strategies could potentially be an effective antiviral strategy for the prevention and treatment of emerging pandemic viruses such as SARS-CoV-2. In this review, we describe recent advances in CRISPR-based diagnostic platforms with an emphasis on their use in the rapid diagnosis and potential treatment of COVID-19.