%0 Journal Article
%T The Effect of DNA and Sodium Cholate Dispersed Single-Walled Carbon Nanotubes on the Green Algae Chlamydomonas reinhardtii
%A Ryan M. Williams
%A Hannah K. Taylor
%A Jackson Thomas
%A Zachary Cox
%A Bridget D. Dolash
%A Letha J. Sooter
%J Journal of Nanoscience
%D 2014
%R 10.1155/2014/419382
%X Increasing use of single-walled carbon nanotubes (SWCNTs) will lead to their increased release into the environment. Previous work has shown negative effects of SWCNT on growth and survival of model organisms. The aim of the current study was to determine the effect of SWCNT well-dispersed by either DNA or sodium cholate (SC) on the unicellular green algae Chlamydomonas reinhardtii in stagnant water conditions. Growth measurements were taken up to ten days for algae treated with varied levels of DNA:SWCNT or SC:SWCNT or controls, and chlorophyll content after 10 days was determined. Results show no effect on either growth or chlorophyll content of algae at any concentration or duration. This is in contradiction to prior work showing toxicity of SWCNT to environmental model organisms. 1. Introduction The increased use of manufactured nanomaterials has led to a need for a better understanding of their potential effects on natural systems. Among these products are single-walled carbon nanotubes, which can be represented by sheets of cylindrically rolled graphene, originally described in 1993 by Iijima et al. [1¨C3]. The widespread commercialization of single-walled carbon nanotubes (SWCNTs) is due to their enormous potential in industrial, biomedical, and electronic sensing applications. This potential is derived from their unique physical, electronic, and optical properties [4¨C8]. The environmental release and transport of SWCNT at all stages of their production and use will lead to environmental concerns [9, 10]. Therefore, it is necessary to study their interaction with organisms in the environment. Previous work has shown that carbon nanomaterials have toxic effects on model organisms. Graphite, C60 fullerene, SWCNT, and multiwalled carbon nanotubes (MWCNT) have been shown to be toxic to various bacterial types and Daphnia magna [11¨C13]. These previous works make it clear that some preparations of SWCNT may have toxic environmental effects. The unicellular green alga Chlamydomonas reinhardtii has been developed as a model for the effects of nanomaterials on photosynthetic microorganisms and indirect assessment of ecosystem-level effects [14]. Work using this model organism has shown toxicity and uptake of silver nanoparticles, quantum dots, and titanium dioxide nanoparticles [15¨C17]. Additionally, C. reinhardtii has been used in finding toxic effects of SWCNT poorly suspended in solution with no surfactant [18]. This work showed a negative effect on growth and photosynthetic output of these algae due to 2£¿¦Ìg/mL of SWCNT aggregates in solution. Some
%U http://www.hindawi.com/journals/jns/2014/419382/