In WP2, the Fellow investigated the research area of magnetophoresis, by bibliography survey and aimed to advance the understanding of the magnetophoresis. Accordingly, a microscopy slide mini Luer platform template for the design was generated in Figure 1A-C.
WP3 considered a key element of this project which was the construction of dual-functionalized MPs via combination of an ultrasensitive redox probe and the specific task biological probes in order to realize the multi-functionalities of MPs in POC devices (such as magnetic manipulation, target capture and signal amplification. Three different strategies were investigated here;
MPs of γ-Fe2O3 dots were synthesized by co-precipitation and stabilized by surface functionalization process of amination and pegylation (Figure 2A). By cross-linking chemistry, the IgG as bio-probe model was conjugated onto the MP surface together with redox probe (Figure 2B) and electrochemical characterization (Figure 2C).
Secondly, a facile synthetic strategy was also used to fabricate such multi-functionalized MPs. TEM images (Figure 3A) of these MPs after coating of three polyelectrolyte layers were characterized to be 11nm of MPs@Fc, while the redox intensity of the three MPs solution at 1.0 mg.mL-1 were electrochemically detected to be around 0.64µA(Figure 3B). Moreover, the binding efficiency of IgG was investigated here, where the IgG was attached to the PSS terminated redox MPs to form biological corona nanoparticle (Figure 3C)
Thirdly, development and learning of surface engineering techniques facilitated the possibility to combine redox and biological properties onto MPs surface. Here, the Fellow developed multi-core MPs (Figure 4A) with a novel strategy to advance redox MPs by covalently conjugated BSA and redox probes (Figure 4B). IgG was efficiently binding onto MPs surface by click chemistry (Figure 4C).
WP4 incorporated the central concept to isolate targets based MPs and free MP, the Fellow initiated work on the design of an advanced microfluidic chip based on magnetic susceptibility gradient (MsG) ranking technique, connected to WP3 & WP2. To complete the novel POC concept, a micro-electrode sensing array was also designed inside the MsG area so that each MP or MP based targets flowing through the sensing electrode can be electrochemically detected.
In WP5, the successfully developed nanoparticles featured with biological, redox and magnetic properties were used for bio-application in order to assess the MPs in a clinical application, Here, exosomes collected from A549 cells culture were used to evaluate the MPs’ function, such as selective bio-capture, efficient magnetic separation, and sensitively electrochemical sensing have collected exosome. In addition, CD63 antigen was also used as a biomarker, to confirm their bio-affinity.
On completion of the project, the Fellow presented to the research group within CBNI an overview and outcomes, key findings and knowledge gained as part of the MSCA Action (Figure 5) and ensured transfer of knowledge with colleagues and students.
