Optimization of Spirulina biofilm for in-situ heavy metals detection with microfluidic-acoustic sensor and AFM
Résumé
Arthrospira platensis, called spirulina (Sp), is known to bind a wide range of heavy metals. We propose an innovative approach, based on Spirulina as bioreceptor combined with highly sensitive Love wave platform for fast detection of heavy metals in solution. Our goal is to optimize the biofunctionalization of the sensor surface with microalgae, based on real-time responses of the acoustic sensor during Spirulina immobilization then heavy metals detection, combined with atomic force microscopy characterization to improve understanding of interaction phenomena. Both methods have proved the efficiency of a microfluidic chip to control the hydrodynamical flow, resulting in a biofunctional layer of microalgae. This work is an application of three generations of PDMS chips already manufactured in IMS of Bordeaux1. In particular, the protocol is optimized from that previously proposed for E. coli bacteria, by using the real-time oscillating frequency due to mass loading during layers deposition : the microalgae is fixed onto the sensor surface coated with a polyelectrolyte multilayer (PEM), and the bioreceptor immobilization response time is greatly reduced using the microfluidic set up.