(306d) On-chip bio-sensor for microbial contamination

Authors: 
Shende, R., South Dakota School of Mines and Technology
Maddipudi, B., South Dakota School of Mines and Technology
Dosch, H., South Dakota School of Mines and Technology
Amar, V. S., South Dakota School of Mines and Technology
Shende, A., South Dakota School of Mines and Technology
Quantification of microbial assay for possible food and water contamination, especially for long-duration space missions is critically important to understand potential risk to the crew members. In this study, on-chip biosensor was fabricated for rapid screening and quantification of microbial contamination. Low-k dielectric (SiO2, Gr- doped SiO2) porous thin-film layers were deposited on ITO by surface templating assisted sol-gel method. Gels were prepared with alkoxides dispersed in ethanol containing CTAC or pluronic123 by varying concentration of precursors and surfactant, and aging time. As spun thin-film substrates were subjected initially to soft-bake followed by annealing at 400oC and characterized for porosity, pore size, and refractive index. Hydrophilic/ hydrophobic nature of the films were characterized by the contact angle measurements. Gr – SiO2 porous layer was immobilized with the anti-microbial peptides (AMP) and specific binding ability of microbes was studied by the conductivity measurements. Fabrication and characterization of porous low-k(modified with Gr) thin-films, and results obtained with AMP binding and biosensing ability will be presented.