Magnetically Barcoded Microcarriers Detection with TMR Sensors

We are working towards a novel lab-on-a-chip technology based on suspended magnetically encoded microcarriers [1], [2]. Our newest generation of microcarriers consist of up to fourteen individual magnetic elements encapsulated within a SU8 polymer and gold layer (Fig. 1.b), which both provide routes to bio-functionalization through surface epoxide groups and thiol chemistry [3]. The writing/reading of the digital magnetic codes is obtained through coercivity engineered magnetic elements (Fig. 1.a), while the detection is performed by means of a tunneling magneto-resistance (TMR) sensor. The global address-ability of these bits is achieved by utilizing magnetic shape anisotropy. The possibility of attaching different fluorescent labels to each side of the microcarriers enables a positive control in binding assays. Potential applications for this platform range from DNA/protein analysis for genotyping and point-of-care diagnostics to drug development and combinatorial chemistry.