The role of the surface ligand on the performance of electrochemical SARS-CoV-2 antigen biosensors

Abstract

Point-of-care (POC) technologies and testing programs hold great potential to significantly improve diagnosis and disease surveillance. POC tests have the intrinsic advantage of being able to be performed near the patient or treatment facility, owing to their portable character. With rapid results often in minutes, these diagnostic platforms have a high positive impact on disease management. POC tests are, in addition, advantageous in situations of a shortage of skilled personnel and restricted availability of laboratory-based analytics. While POC testing programs are widely considered in addressing health care challenges in low-income health systems, the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections could largely benefit from fast, efficient, accurate, and cost-effective point-of-care testing (POCT) devices for limiting COVID-19 spreading. The unrestrained availability of SARS-CoV-2 POC tests is indeed one of the adequate means of better managing the COVID-19 outbreak. A large number of novel and innovative solutions to address this medical need have emerged over the last months. Here, we critically elaborate the role of the surface ligands in the design of biosensors to cope with the current viral outbreak situation. Their notable effect on electrical and electrochemical sensors’ design will be discussed in some given examples. Graphical abstract

A mask-based diagnostic platform for point-of-care screening of Covid-19

“…This sensing sensitivity of the maleimide-thiol aptamer sensor is comparable to other electrochemical ( Saroglia et al, 2021 , Szunerits et al, 2021 , Zhang et al, 2020 ) and electrical ( Seo et al, 2020 ) sensors reported thus far in the literature. In addition, the possibility of detecting the variants 20I/501Y.V1(called “British variant”) and 20H/501Y.V2 (called “South African variant”) was investigated by using SARS-CoV-2 variant isolates.…”

SARS-CoV-2 electrochemical immunosensor based on the spike-ACE2 complex

“…Spike protein is repeated 50–200 times on the viral surface [ 42 ] and consists of approximately 1273 amino acids [ 43 ], of which around 200 correspond to the RBD region (amino acid residues 331–524) located in the S1 subunit of the protein [ 44 ]. ACE2 is a protein of 805 amino acids formed by the N-terminal peptidase and the C-terminal choleric domains.…”

COVID-19 Biomarkers and Advanced Sensing Technologies for Point-of-Care (POC) Diagnosis

“…This sensor was able to detect COVID-19 in a couple of patients, and the results were comparable to that of commercial ELISA. The responses are monitored with square-wave voltammetry [141][142][143]. In other electrochemical detection applications, it was demonstrated that SARS-CoV-2 can be detected in saliva.…”