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Pedro Alvarez

Current Projects

Bio-response to Adsorption of Nanomaterials with Different Adsorbents

In recent decades, nanotechnology has been booming in both scientific and marketing areas. Nanosized materials are often hailed for their extraordinary properties. But these also raise concerns of unique toxicity. What is the transfer and fate of these nanomaterials, what kind of bio-impact will they bring are still waiting for exploration. Microbes, as the foundation of the whole biosphere, deserve the primary concern to study their response when exposed to nanomaterials. On the basis of former study, which has shown toxicity of nC60 (fullerene-water suspension) to bacteria, we are examining bacterial response to nC60 when n60 is adsorbed to different adsorbents. Granular activated carbon, silica gel and polystyrene beads are chosen to test the relationship between toxicity of nC60 and bioavailability.

Implications and Applications of the Toxicity of Nanoparticles

As nanotechnology flames the enthusiasm of scientific and technical communities, research aimed at preventing adverse consequences is also occurring at an unusually early stage in the development cycle of a new technology. Our team positions itself in line with this trend: in parallel, we are working on the mechanisms of antibacterial properties of nanoparticles and on the development of engineered disinfection systems. In our proactive approach to nanotoxicity management, our objective is to place a positive spin on the bactericidal properties by, for example, using nanoparticles as a new key substance in the processes of drinking water treatment. More specifically, we focus on fullerene (C60 and nC60), fullerol and carbon nanotubes suspended in solvents (water or organic solvent). We examine their photosensitivity while exposed to UV light. We are also currently loading these nanoparticles in polymeric membranes to ascertain their effect on the mechanical and separation properties of the membranes, while expecting a significant reduction of biofouling.

 Current Research - Nanoparticles 1

 Current Research - Nanoparticles 2

Nanomaterial-Bacterial Interactions

The widespread production of engineered nanomaterials and their rapid incorporation into a variety of consumer products and applications is outpacing the research into their health and environmental impacts. Currently, the degree to which cellular processes and ecosystem health may be impacted by nanomaterials, let alone specific toxicity mechanisms, remain largely unknown. The effect of these nanomaterials on microbes is an important consideration due to the role of microbes as the basis of food webs and the primary agents for global biogeochemical cycles. Microorganisms are also important components of soil health and could serve as potential mediators of transformations that affect nanoparticle mobility and toxicity in the environment. In an attempt to contribute to proactive risk management, our research examines the potential impacts of nanomaterial use and disposal on microbes, with the primary focus on fullerenes. We have examined the antibacterial activity of SiO2, TiO2, ZnO, and a fullerene-water suspension named nC60. We are currently determining the mechanism behind the antibacterial activity of nC60 to prevent unintentional ecosystem damage and/or exploit its antibacterial properties in engineered disinfection systems.  We are also monitoring the impact of nC60 and powdered C60 on soil microcosms to ascertain the effect of fullerenes on soil microbial communities.