Fig. 1. Developing microfluidic graphene Hall sensors (μGS) for rare cell detection.

a Schematic of a cell labeled with ligand-specific nanoparticles traveling over a single μGS with a perpendicularly applied magnetic field. b Micrograph of the PDMS microfluidic channel covering the sensor region. The applied magnetic field is indicated as coming out of the page. c Micrograph of a magnetic agarose bead passing over the sensors