Development of a biosensor for hCGβ detection

Abstract

Detection and concentration monitoring of Human Chorionic Gonadotropin (hCG) and especially, its free beta-subunit, hCGβ, is critical for various aspects of the human health. From pregnancy tests to monitoring hCG and hCGβ blood levels, they provide physicians valuable information concerning the progress of a pregnancy and the health of a fetus. More importantly, they can also be used as markers of gestational trophoblastic disease (GTD), germ cell tumours and some non-trophoblastic tumours. Detection of hCGβ is also critical for patient treatment monitoring and for relapse detection. According to the literature, the use of hCGβ as a tumour marker is limited by the lack of high sensitivity and specificity sensors. In this paper we present the first two steps of the development of an impedance biosensor, based on the formation of a stable antibody-antigen complex on gold microband electrodes and the preliminary results and analysis of the interface processes, relating the physical structure of the sensor to its electrical behaviour using EIS. © Springer-Verlag 2007.