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0915-R01-08

Enhancement of Antibody Binding on SiO2 Love Wave Sensor Surface using (3glycidoxypropyl)trimethoxysilane Nicolas Moll1, Duy Haï Dinh1,2, Emilie Pascal3,4, Corinne Déjous1, Jean-Paul Pillot2, Bernard Bennetau2, Dominique Rebière1, Daniel Moynet3, Yan Mas4, and Jacques Pistré1 1 Laboratoire IXL, 351, cours de la Libération, Université Bordeaux 1, Talence, 33405, France 2 Laboratoire de Chimie Organique et Organométallique, 351, cours de la Libération, Université Bordeaux 1, Talence, 33405, France 3 Laboratoire d'Immunologie et Parasitologie, Université Bordeaux 2 Victor Segalen, 146, rue Léo Saignat, Bordeaux, 33076, France 4 AGUR, 5, rue de la Feuillée, Bayonne, 64100, France

ABSTRACT 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. INTRODUCTION Immunosensors have been used extensively during the last few years in a number of applications as an alternative immunoassay technique. The detection principle of this new generation of devices is based on monitoring one or more physical parameters at a solid/liquid interface during the interaction of a biomolecule. Among the immunosensors available, the most promising systems are those that can detect specifically the immunological reaction in real time with high sensitivity. Many successful immunosensors are based on the monitoring of optical properties of the interface, like Surface Plasmon Resonance (SPR) [1] and the Resonant Mirror (RM). Another class of immunosensors uses acoustic techniques: they are based on Surface Acoustic Wave (SAW) devices, and especially Love Wave devices which offer extremely high sensitivity and can be used in liquid medium [2-4]. This paper deals with studies on Love wave sensors to detect biological species, and focuses on the grafting of the bioreceptor. Indeed, this critical pathway is expected to play a major role on the sensor performances. In order to realize a specific, highly sensitive and uniform layer enabling to ensure efficient and reproducible immobilization of biological species, we present and analyse results regarding the use of GPTS as coupling agent to bind antibodies onto the SiO2 surface.

LOVE WAVE SENSORS The basis of Love-wave devices is a shear horizontal guided surface acoustic wave delay line consisting in a piezoelectric substrate with two interdigitated electrodes, called interdigital transducers (IDT), separated by an acoustic propagation path (Fig. 1). Using quartz substrate, t