Development of a nucleic acid-based screen printed electrochemical biosensor using Ti3C2Tx-MXene for the detection of SARS-CoV-2

Abstract

The SARS-CoV-2 virus poses a major risk to human health which has put a tremendous strain on already stretched healthcare resources. Despite continuous improvements in Coronavirus Disease-19 (COVID-19) detection, treatment technology and ongoing global immunization efforts, the lethal virus has undergone several mutations and is still claiming millions of lives worldwide. In this respect, the development of a hybridization-based nucleic acid biosensor for SARS-CoV-2 virus is the major focus of the current effort in response to the critical demand for developing quick and accurate diagnostic methods. Herein, we employ Screen Printed Carbon Electrode (SPCE) coated with Ti3C2Tx-MXene nanosheets followed by amino-functionalized probe DNA (NH2-pDNA) as a robust surface for the sensing of SARS-CoV-2. Electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry were employed for assessing the electrochemical behavior of NH2-pDNA/Ti3C2Tx/SPCE bioelectrode. Meanwhile, the analytical sensor response for SARS-CoV-2 was studied using impedance within target DNA concentration of 0.1 pM − 1 µM. The developed biosensor displayed detection limit of 0.004 pM, showing a high degree of selectivity in the presence of non-complementary interferents with a shelf life of 40 days. Additionally, a good linearity for the detection of target sequence in spiked serum samples was established; as a result, exhibiting huge potential for use in the contemporary healthcare sector for fast, accurate and reliable diagnosis of COVID-19 in a point-of-care scenario.