A biosensor chip based on filtration is developed for circulating tumor cell（ CTC） detection. The chip consists of three layers

that are an upper sample injection chamber

a filtering membrane and a lower effluent chamber. Healthy blood samples with tumor cells H446 and clinical lung cancer patient ’s blood samples are loaded into the chip to test detectability of the chip. The results suggest that the microfiltration chip has detectability with high speed and high efficiency

the chip is proved to have a better clinic detectability than traditional immumo-magnetic beads method

it is proved that the chip provides an practical tool for CTC detection with easy operation

fast

and high efficiency.