New Perspectives in Science Education

The use of metal and metal oxide nanoparticles, such as silver, copper and zinc oxide, in everyday life objects is steadily increasing. Nano-labeled products appear frequently in our daily lives and one is often confronted with them without even knowing it. Zinc oxide nanoparticles for instance, find application as physical UV-filters in cosmetics, sun protection and skin care products ^[1]. Furthermore, due to their antibacterial properties, zinc oxide nanoparticles are used in hygiene products ^[1]. Just like zinc oxide, silver and copper nanoparticles are known for their antibacterial effects, which is why they are used in fabrics as well as medicine ^{[2, 3]}. Due to the increasing use of these nanoparticles, it can be expected that the entry of nanoscale materials into the environment is steadily growing.

Even though there are currently only a few studies on the effects of nanomaterials on humans and the environment, current research reveals that some of these materials present certain risks ^[4]. For example, current studies prove an increased biotoxicity of silver nanoparticles on microorganisms such as Escherichia coli ^[5].

To demonstrate the possible effects of nanomaterials on microorganisms, a series of experiments were elaborated for use in both high school and university laboratory classes. Apart from the synthesis of metal and metal oxide, we present model experiments on the diffusion of nanoparticles through cell membranes as well as experiments on the effects of metal and metal oxide nanoparticles on microorganisms. Furthermore, an experiment inspired by Kurt Winkelmann ^[6], that demonstrates the influence of nanoparticles on the alcoholic fermentation of Saccharomyces cerevisiae, also known as baker’s yeast, is presented. In conclusion, we will give some examples of how to implement these experiments in chemistry school classes.

References

[1] B. Rohe, Synthese, Charakterisierung und Applikationen von unbeschichteten, silan-beschichteten und UV-modifizierten Nano-Zinkoxiden, Dissertation, Universität Duisburg-Essen 2005. [2] J. Diendorf, Silber-Nanopartikel – Synthese, Stabilität und biologische Wirkungen, Dissertation, Essen 2012. [3] C. Steinbach, Daten und Wissen zu Nanomaterialien: Kupfer und Kupferoxide - Materialinfo, Frankfurt, http://www.nanopartikel.info/nanoinfo/materialien/kupfer-und-kupferoxide/materialinfo-kupfer [21.11.2014] 2013. [4] H. Schmundt, M. Verbeet, Spiegel, 2008 (24), 2008. [5] H. Schwegmann, Wechselwirkungen zwischen anorganischen Nanopartikeln und Mikroorganismen, Dissertation, Karlsruher Institut für Technologie 2013. [6] Florida Institute of Technology, http://www.fit.edu/faculty/profiles/profile.php?tracks=kwinkel [25.11.2014]