Abstract

Interdigitated Gold Nanowires for Impedimetric Detection of SARS-CoV-2 Antibodies

Diana Isabel Sandoval Bojorquez, PhD Student, Helmholtz Zentrum Dresden Rossendorf

In the current COVID-19 pandemic it has become evident that the development of biosensors is extremely important for screening and surveillance in the different stages of infection, disease progression and recovery. Here, we developed a system which can be used for the detection of antibodies that are present during and after the infection with SARS-CoV-2. Our sensor chips are composed of six sensing devices, each of these containing interdigitated gold nanowires. The gold surface of the nanowires was modified by HS-PEG(5k)-COOH layer formation followed by coupling of SARS-CoV-2 receptor binding domain (RBD) as antigen via amide bond formation. The detection IgG antibodies for SARS-COV-2 present in solution was performed using the impedance spectroscopy technique. For these purposes, an AC signal over a range of frequencies between 20 Hz and 1 MHz was applied to the sensor chips and the changes in impedance and phase were measured. The change in the overall impedance of the system was correlated to antigen-antibody binding events. The developed sensing system is a versatile platform that could be easily adapted to detect relevant biomarkers in different diseases.