Optimization of physicochemical parameters of a multilayered polyelectrolyte film deposition with Love wave and AFM for bacteria based detection of heavy metals
Résumé
A biosensor based on Escherichia coli Bacteria for determination of heavy metal ions with an acoustic Love wave device and Polydimethylsiloxane (PDMS) microfluidic network has been previously developed, that provides fast detection of toxic chemical compounds. Bacteria were immobilized on the transducer coated with self-assembled molecular multilayers of polyelectrolytes. In this study, we emphasize Love wave and AFM-based complementary characterization methods, which allowed an optimization of some physicochemical parameters of polyelectrolyte solutions, such as pH, ionic strength or molecular weight, in order to increase the immobilization of bacteria as well as the sensor lifetime. For instance, an increase density of bacteria was observed when using alternative pH of 9 for cationic solution.