A novel piezoelectric quartz crystal immnuosensor based on hyperbranched polymer films for the detection of α-Fetoprotein

This paper reports a novel piezoelectric quartz crystal immnuosensor based on hyperbranched polymer films for the detection of α-Fetoprotein. In this strategy, the sensing interfaces consist of a primary cystamine monolayer assembled onto Au electrodes associated with the piezoelectric quartz crystal. The monolayer is further modified with a new hyperbranched polymer which was synthesized through direct polycondensation of monomer 5-[3-(4-aminophenyl) propionylamino] isophthalic acid. The detection performances of resulting immunosensor were investigated by use of the antibody-antigen model system of α-Fetoprotein (AFP), an important indicator in the diagnosis of clinical cancers. The analytical technique is characterised through the investigation of different methods of assembling the monolayers used as supports, as well as by comparing two different types of supports. It was found that the developed sensing interface could perform more effectively in antibody-antigen binding and consequently increased the sensitivity of the whole piezoelectric immunosensor. Moreover, the method should also be useful for the construction of other kind of immunosensors.