An acoustic Love wave immunosensor dedicated to detect biological species such as bacteria, viruses or toxins is described in this paper. We present and analyze results of antibody grafting on the Love wave device using GPTS as coupling agent between SiO2 sensor surface and the sensitive biomembrane layer composed of antibodies. Goat anti-mouse (GAM) antibodies at concentrations from 2μg/ml to 50 μg/ml were introduced on the sensor brass cell. The saturation of the sensor surface by antibodies appears at a concentration of 20 μg/ml. The detection threshold of this primary antibody is around 2 μg/ml, and the lowest concentration allowing antigen detection is around 5 μg/ml.