A microfluidic system with surface modified piezoelectric sensor for trapping and detection of cancer cells.

We present a microfluidic system with integrated surface modified piezoelectric sensor for trapping and label-free detection of target samples that can be used for cancer diagnosis. To introduce active magnetic force control to the piezoelectric sensor and obtain a fast regenerative system, a nickel pillar array was patterned onto the surface of quartz crystal microbalance. The functionalities of the system were tested by trapping suspended superparamagnetic micro-beads (SPMBs) in fluids onto the nickel pillar array with a manually controlled magnetic field and by detecting the accumulated mass from the resonant characterization of the piezoelectric sensor at the same time. The results showed the efficiency of the system in manipulating the SPMBs and the sensitivity of the device was of 5 Hz mm2/ng. With surface-functionalized SPMBs, the microfluidic system succeeded in trapping and detecting target cancer cells. A549 cancer cells were captured on the nickel pillar array with WGA protein-functionalized SPMBs and detected with a total mass of 90.6 ng. With its simplicity, low production cost and high efficiency, this new device configuration would be useful for the future point-of-care clinical applications.