Optimizing silica matrices for microalgae-biosensors based on optical detection methods

ANA MERCEDES PERULLINI; FERRO, YANNIS; CLAUDE DURRIEU; M. JOBBAGY,; ALDABE BILMES, SARA

Madrid

Congreso; XVII International Sol-Gel Conference; 2013

International Sol-Gel Society (ISGS)

In this work we propose the optimization of the two-step procedure to the design and construction of silica-based algal biosensors for applications in monitoring of polluted water by optical detection methods. To this aim, we have enhanced the protective function of the alginate cover with a buffer that regulates the pH value in the immediacy of the algal cells during the acid sol-gel synthesis of the silica matrix. With this strategy we achieved a high initial viability (ca. 100%) for different algal species (Chlorella vulgaris, Pseudokirchneriella subcapitata and Chlamydomonas reinhardtii) encapsulated in translucent alcoxide-derived silica hydrogels synthesized at pH 4. The effect of the gradient of pH in the silica-alginate interface on the sol-gel synthesis is further assessed by small angle X ray scattering (SAXS), since it is known that slight variations in pH may cause a significant change in the microstructure of the host matrix. Finally, a prototype biosensor was developed and its performance was compared to that of a silicate-Ludox based similar device.