Development of Electrochemical Biosensor Platforms for Determination of Environmental Viral Structures

Infectious diseases caused by viruses (such as influenza, Zika, human immunodeficiency, Ebola, dengue, hepatitis, and COVID-19 virus) are diseases that have been on the agenda of the whole world for the last quarter of a century and have become one of the most important problems for people. Urgent identification of the people infected with a disease will allow these people who have contracted the disease to be treated effectively. In this context, the polymerase-chain-reaction (PCR)-based methods have been the most common and widely used method that responds with sensitivity. However, due to some disadvantages encountered in PCR applications (in particular, the test protocol is comprehensive, not fast in terms of time, not economical, requires user expertise, is not suitable for field/on-site measurements, etc.), a new generation (which can give fast results, are economical, sensitive, suitable for on-site application, etc.) of systems that can provide solutions are needed. On the subject of different test-diagnostic applications used in a large number of test-based analysis methods and techniques, electroanalytical systems have some advantages. Within the scope of this presentation, low-cost, miniaturized electrochemical platforms for surface-printed electrodes by using appropriate biochemical and viral structures of the electrode surfaces decorated with suitable agents are explained. These platforms can be used in the determination of some particular viral proteins for the understanding of viral pathogenic diseases. In this study, a copper-modified graphite electrode was developed and characterized with SEM. Afterwards, an antibody of the N protein of COVID-19 was decorated surrounding this electrode to measure the amount of that protein in the samples. The square wave voltammetry (SWV) technique was used for the electrochemical detection of SARS-CoV-2. When the results of the analyses were examined, the best analytical sensitivity and linearity were obtained by incubating the antibody-modified electrode and virus antigen for 10 min. The measurements showed linearity with a high correlation coefficient (R2 = 0.9917). The detection limit (LOD) was calculated as 508 pg/mL. The measurement limit (LOQ) was calculated as 1.54 ng/mL. With the pencil tip, which is an easily accessible material for the modified electrode system we designed, a very precise measurement was provided for the rapid detection of the N protein of the SARS-CoV-2 virus at very low concentrations.