Science

Name of the applicant (institution) State research institute Center for Physical Sciences and Technology

Project partner Kaunas University of Technology
Project "Biosensor based on nanolayered structures for SARS-COV2 virus detection“

Project No. 13.1.1-LMT-K718-05-0015 (former 01.2.2-LMT-K-718-05-0068)

Research leader Prof. Dr. Nerija Žurauskienė

Project duration 03-11-2021 – 31-08-2023

Project funding 299729.51 EUR

 

Summary of final report 

Early detection of SARS-CoV-2 is very important to prevent the rapid spread of the disease, especially given the fact that there is a constant increase in mutations that can negatively affect diagnostic accuracy. Conventional methods such as PCR (polymerase chain reaction) and ELISA (enzyme-linked immunosorbent assay) are not suitable for rapid, large-scale testing. Therefore, scientists are actively searching for an affordable, reliable and simple method to accurately detect SARS-CoV-2.

The main aim of this project is to develop technologies of sensors based on nanolayered structures and to create a biosensor prototype for SARS-COV2 virus detection.

The main task is to develop technologies for the growth of nanolayered structures from magnetic and graphene layers and to create a prototype of biosensor for the detection of SARS-COV2 virus.

The project has developed technologies for the growth of magnetoresistive (MR) structures (colossal CMR, giant GMR, Heusler alloys) using pulsed-injection MOCVD and magnetron sputtering, optimising both the growth conditions and the thickness of the layers as well as the chemical composition of the materials. A GMR spin valve configuration was identified and fabricated showing the magnetoresistive properties that met the requirements for biosensor development: Si/SiO2/Ta(5nm)/IrMn(15mn)/CoFe(4nm)/Cu(2.5nm)/CoFe(5nm)/Ta(5nm). In parallel, the microwave plasma-activated chemical vapour deposition technology (MW-PECVD) for direct synthesis and method of transfer of commercial graphene onto the substrate were developed. The analysis of the structure and surface morphology of graphene layers by Raman scattering spectroscopy and atomic force microscopy was used to optimise the MW-PECVD technology, aiming at the minimum number of graphene layers and the minimum number of defects and the maximum charge carrier mobility. Surface functionalisation and immobilisation with specific biomolecules and a microfluidic system for the detection of the SARS-COV-2 spike protein were developed.

A prototype biosensor has been developed using a graphene field-effect transistor (G-FET) configuration. After functionalisation of the graphene surface and immobilisation of the ACE2 receptor, the transmission characteristics of the liquid-gated G-FET were measured in a microfluidic system, and the dependence of the Dirac voltage shift on the concentration of SARS-COV-2 virus spike variants up to 50 µg/ml was determined. The limit of detection (LoD) for virus spike proteins was experimentally obtained to be 10-50 ag/mL, depending on the virus variant. It was concluded that both the transferred and MW-PECVD directly synthesised graphene FET biosensor, with its high sensitivity and low LoD, has an excellent potential for application in COVID-19 diagnostics.

The project was carried out by the scientists of the Center of Physical Sciences and Technology together with the scientists of the partner Kaunas University of Technology. Project implementation results: two published scientific publications (https://doi.org/10.3390/s22114004; https://doi.org/10.3390/nano13162373), one article submitted to the journal, and developed biosensor prototype for SARS-COV2 virus detection (description provided at the internet address: https://www.ftmc.lt/department-of-functional-materials-and-electronics (Projects).

 

Funded under measure 01.2.2-LMT-K-718 ‘Targeted Research in Smart Specialisation Areas’ of priority axis 1 ‘Promotion of research, development and innovations’ of the Operational Programme for the European Union Funds’ Investment in 2014–2020.