A novel paper immunosensor which was made up of a sample tab and an auxiliary tab was fabricated. The microfluidic channel was built through wax printing while the electrodes were through screen-printing.

A new label-free electrochemical method was used during measurement, which avoids labeling either antigens or antibodies, to make the detection of CEA faster, simpler and cheaper. Combining the method with paper- based device, a fully functional μPAD was made, which truly realized the target of point-of-care testing.

NH₂-G/Thi/AuNPs nanocomposites was successfully synthesized and used to modify the working electrode. After modification, the working electrode possessed high bioactivity and could be used to detect CEA.