Antigen-antibody selective recognition using LiTaO₃ SH-SAW sensors: investigations on macromolecules effects on binding kinetic constants

¹ Unité de Recherche de Physique des Semiconducteurs et Capteurs, IPEST, 2070 La Marsa, Tunisia
² Laboratoire de Physique, EA 4131, Cnam, 2 rue Conté, 75003 Paris, France

^a e-mail: zerrouki@cnam.fr

Received: 31 May 2010
Accepted: 10 January 2011
Published online: 28 September 2011

Abstract

A gravimetric surface acoustic wave (SAW) biosensor, based on the biotin-streptavidin and antistreptavidin-streptavidin recognitions, has been carried out. A network analyser and a pulse excitation technique were used to monitor both amplitude and phase changes. The SAW biosensor presented a total selective recognition of streptavidin-antistreptavidin and HRPstreptavidin-antistreptavidin. The presence of HRP (Horseradish peroxidase) affects neither the selectivity nor the sensitivity (of order of 0.25°/nM) of the biosensor, nevertheless, it causes a reduction of binding kinetics by a factor ranging between 2 to 5, as well as a diminution of antistreptavidin saturation concentration (of 40%). Results showed that equilibrium constants can be different, depending on evaluation method (from saturation values or from linear part of the output signal variation according to solution concentration).