Functionalized TiO2 nanotube-based Electrochemical Biosensor for Rapid Detection of SARS-CoV-2

Abstract

ABSTRACTThe COronaVIrus Disease (COVID-19) is a newly emerging viral disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Rapid increase in the number of COVID-19 cases worldwide led the WHO declare pandemic within a few month after the first case of infection. Due to the lack of a prophylactic measure to control the virus infection and spread, early diagnosis and quarantining of infected as well as the asymptomatic individuals are necessary for the containment of this pandemic. However, the current methods for SARS-CoV-2 diagnosis are expensive and time consuming although some promising and inexpensive technologies are coming out for emergency use. In this work, we report the synthesis of a cheap yet highly sensitive cobalt-functionalized TiO2 nanotubes (Co-TNTs)-based electrochemical biosensor and its efficacy for rapid detection of spike glycoprotein of SARS-CoV-2 by examining S-RBD protein as the reference material. A simple, low-cost, and one-step electrochemical anodization route was used to synthesize TNTs, followed by an incipient wetting method for cobalt functionalization of the TNTs platform, which is connected to a potentiostat for data collection. This sensor specifically detected the S-RBD protein of SARS-CoV-2 even at very low concentration (range of 14 nM to 1400 nM). Additionally, our sensor showed a linear response in the detection of viral protein with concentration range. In summary, our Co-TNT sensor is highly effective in detecting SARS-CoV-2 S-RBD protein in approximately 30 seconds, which can be explored for developing a point of care diagnostics for rapid detection of SARS-CoV-2 in nasal secretions and saliva samples.AUTHOR SUMMARYSARS-COV-2 is currently a global pandemic on a scale that has not been experienced since the Spanish flu of 1918. One of the reasons why this pandemic virus has spread so quickly is because many infected individuals with SARS-CoV-2 remain asymptomatic and involuntarily transmit the virus before they come down with the symptoms. Therefore, uniform surveillance and quarantining of infected as well as the asymptomatic individuals could provide an effective measure to contain the spread of SARS-CoV-2. However, the current methods for SARS-CoV-2 diagnosis are expensive and time consuming although some inexpensive technologies are getting approvals for emergency use. Our manuscript reports the synthesis of a cheap yet highly sensitive cobalt-functionalized TiO2 nanotubes (Co-TNTs)-based electrochemical biosensor for rapid detection of spike glycoprotein of SARS-CoV-2. Our sensor is synthesized through one-step electrochemical anodization route, followed by an incipient wetting method for cobalt functionalization of TNTs platform. The readout of this sensor is an electrochemical signal collected through a potentiostat, which can be adopted for use through smartphone applications and the development of a point of care diagnostics for COVID-19.