@@The use of bead-based immunoassay in microfluidic chips has been a focus of growing interest in recent years1-3. Microbeads as solid supports can further enhance the performance of microfluidic devices by improving surface-to-volume ratio for reactions. Because of high throughput, short analysis time, small sample volume and high sensitivity, bead-based microfluidic devices are especially vital to point-of-care testing for clinical diagnose.