A system includes a control module and a microfluidics chip. The control module includes electromagnets. The microfluidics chip includes two bead sets, a substrate, a channel layer disposed on the substrate, and a flow-control layer disposed on the channel layer. The channel layer has a central recess, channels in communication with the central recess, and cavities in communication with the channels. The flow-control layer has through holes aligned with the cavities of the channel layer. The through holes and the cavities cooperatively form wells. The flow-control layer includes micro-valves corresponding in position to the channels, and magnetic components connected to the micro-valves. A sample is disposed in one of the wells, and the bead sets are coated with aptamers and attach to another two of the wells. The electromagnets control the micro-valves to allow flow of the sample and to allow the sample to be mixed with the bead sets. |