Magnetic nanoparticles for diagnostic applications
The objective of this interdisciplinary project is to develop sensitive, low-cost, fast and user-friendly bioassays, that can be used in diagnostic platforms for detection and identification of different types of pathogens, such as virus or bacteria. The scientific approach relies on different molecular tools for recognition and amplification of a specific target (DNA/RNA). The molecular tools include for example the padlock probe ligation assay, rolling circle amplification and circle-to-circle amplification.
These tools are combined with magnetic readout based on changes in the dynamic magnetic response of probe-functionalized magnetic nanoparticles which is induced by the binding of the amplified DNA products to the surface of the magnetic nanoparticles. The hydrodynamic volume increase of the magnetic nanoparticles causes a larger rotation time, and thus a lower the rotation frequency. By detecting the frequency shift in the peak position in the magnetization spectra the number of attached target molecules can be probed. The read-out of the developed bioassays is accomplished by the use of two different magnetic sensor setups, an AC suspetometer (left, in the picture below) and an otpomagnetic sensor (right, in the picture below), where the results indicates both presence/absence and concentration of the targeted pathogens.
The long-term aim is to introduce a new class of diagnostics that may impact both veterinary and human healthcare by giving decentralised care providers tools to perform advanced diagnostics at a low cost. Diagnostic tests that do not need expensive equipment, complicated machinery or trained personnel are valuable assets in the fight against diseases across the globe.
Projects
Analysis and determination of antibiotic resistance (ongoing)
A new detection approach is being developed for the identification of bacteria resistant to antibiotics. The new detection approach is based on the formation of large and visible aggregates resulting from the interaction between magnetic nanoparticles and DNA products. This method is a versatile tool for detecting DNA in point-of-care diagnostics. The project aims to study, adapt and optimize the biosensing method.
Development of magnetic bead-based diagnostic assays for detection of pathogens for zoonotic diseases (2012-2020)
The objective of this project was to develop bioassays based on isothermal DNA amplification and magnetic nanoparticle targeting for the detection of pathogens that present zoonotic threat to humans, such as Salmonella and Newcastle Disease.
FLU-ID (2015-2020)
The purpose of this project was to develop a low-cost and portable nano-diagnostics unit, which would provide an efficient analytical platform for rapid detection of pandemic influenza directly at the point of care. The bioassay principle was based on the ligation and rolling circle amplification techniques in combination with magnetic readout. The project was in collaboration between Uppsala University, Stockholm University, Karolinska Institute, Chalmers and Acreo Swedish ICT.
