Mesoporous TiO2 Coating for Increased Sensitivity of Love Wave Delay-Lines for Heavy Metal Detection
Résumé
This work deals with the design of a highly sensitive acoustic Love waves biosensor for heavy metal detection in liquid medium. Biorecepting Escherichia coli bacteria are immobilized on polyelectrolyte multilayers, and are used to detect the presence of cadmium by modification of viscoelastic properties of bacteria. The different setups of sensor elaboration are measured through the real-time resonant frequency shifts of the sensor. The impact of the addition of a titania mesoporous coating is studied, and compared to previous results. Frequency variation for bacteria immobilization is doubled with titania compared with bare silicon dioxide surface. The improvement of the acoustic platform sensitivity is highlighted with cadmium as typical heavy metal. A complementary study was done by Atomic Force Microscopy (AFM) and allowed us to validate the assumptions.