A new antibody immobilization approach has been proposed for the piezoelectric immunosensors through metal ion chelation. The piezoelectric quartz crystal surfaces were first coated with the plasma-polymerized films of butyl amine (BA-PPF) by using a radio frequency plasma deposition technique. The BA-PPFs were modified with amine triacetic acid groups, and the diethylenetriaminepentaacetic acid-modified IgG antibody (DTPA-IgG Ab) was then immobilized through mediating chelation of metal ions. The piezoelectric immunosensor could detect the normal human IgG in the range of 0.36～63.8 mg/mL. This simple and effective immobilization approach is of certain potential to be a common immobilization for piezoelectric immunosensor construction.

Key words: plasma-polymerized film, metal ion chelation, immobilization approach