A biochip device for detection of biologic molecules in a fluidic sample is disclosed in this invention. The biochip device comprises a plastic substrate, an IC chip, a sealing cover and a vacuum bag. The plastic substrate comprises a variety of microfluidic structures including an inlet region of loading the fluidic sample, a separation structure, a microfluidic channel, a structure for slowing the flow of the fluidic sample, a reaction region, a detection zone groove, and a closed area for collecting the fluidic sample. The plastic substrate is embedded with an IC chip and covered by a sealing cover made of polydimethylsiloxane, which is encapsulated by a vacuum bag, whereby the microfluidic structures in the plastic substrate are kept in vacuum state inside the vacuum bag.