Capacitive immunosensor for transferrin based on an o-aminobenzenthiol oligomer layer Original Research Article

A capacitance immunosensor based on an oligomer layer on gold was developed. o-Aminobenzenethiol (o-ABT) forms self-assembled layer (SAL) on polycrytalline gold surface. The SAL was polymerized electrochemically, then an oligomer of o-ABT was formed on the gold surface with some free-reacted ∼NH2 as functional groups to react with glutareldehyde (GA). The transferrin antiserum was covalently coupled on the gold surface by GA. The transferrin was determined with a detection limit of 0.12 ng/ml and a linear detection range of 1.25–80.0 ng/ml.