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Effects of the interaction between TiO2 with different percentages of exposed {001} facets and Cu(2+) on biotoxicity in Daphnia magna.

Liu L, Fan W, Lu H, Xiao W - Sci Rep (2015)

Bottom Line: The results indicated that the addition of Cu(2+) enhanced agglomeration-sedimentation of TiO2, resulting in the reduction of TiO2 bioaccumulation by 10% to 26%.TiO2 nanoparticles (NPs) increased copper bioaccumulation by 9.8%, whereas the other four TiO2 nanosheets (NSs) decreased it by 43% to 53%, which depended on TiO2 variant adsorption and free Cu(2+) concentrations in the supernatant.This research highlighted the important role of the percentage of exposed {001} facets in nanostructured TiO2 on bioaccumulation and biotoxicity of TiO2 and Cu(2+) in Daphnia magna.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191, Beijing, P. R.China.

ABSTRACT
Anatase TiO2 nanosheets (NSs) with exposed {001} facets have been widely used because of their high activity and particular surface atomic configuration. However, investigations on their biotoxicity are rare. In this study, bioaccumulation of five different TiO2 (with 10%, 61%, 71%, 74% and 78% exposed {001} facets), as well as copper and enzyme activities in Daphnia magna, are systematically investigated and rationalized. The results indicated that the addition of Cu(2+) enhanced agglomeration-sedimentation of TiO2, resulting in the reduction of TiO2 bioaccumulation by 10% to 26%. TiO2 nanoparticles (NPs) increased copper bioaccumulation by 9.8%, whereas the other four TiO2 nanosheets (NSs) decreased it by 43% to 53%, which depended on TiO2 variant adsorption and free Cu(2+) concentrations in the supernatant. The levels of superoxide dismutase (SOD) enzyme and Na(+)/K(+)-ATPase activities suggested that oxidative stress, instead of membrane damage, was the main toxicity in D. magna. Meanwhile, the SOD enzyme activities increased with decreasing Cu accumulation and increasing Ti accumulation because of the different functions of Cu and Ti in organisms. This research highlighted the important role of the percentage of exposed {001} facets in nanostructured TiO2 on bioaccumulation and biotoxicity of TiO2 and Cu(2+) in Daphnia magna.

No MeSH data available.


Related in: MedlinePlus

TEM images of the NP10(a) and NS78 (b) samples.
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f1: TEM images of the NP10(a) and NS78 (b) samples.

Mentions: TiO2 NPs (NP10) and NSs (NS78) were characterized by TEM, as shown in Fig. 1. The morphology of TiO2 NSs with 78% {001} facets (Fig. 1b) was different from that of TiO2 NPs with 10% {001} facets (Fig. 1a). According to Table 1, the shape of TiO2 changed from NPs to NSs with increasing RF. TiO2 with 61%, 71%, 74%, and 78% {001} facets were nanosheets, whereas those with 10% {001} facets were nanoparticles. The morphologies of TiO2 NS61, NS71, and NS74 were similar to that of NS78 (TEM pictures not shown).


Effects of the interaction between TiO2 with different percentages of exposed {001} facets and Cu(2+) on biotoxicity in Daphnia magna.

Liu L, Fan W, Lu H, Xiao W - Sci Rep (2015)

TEM images of the NP10(a) and NS78 (b) samples.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525146&req=5

f1: TEM images of the NP10(a) and NS78 (b) samples.
Mentions: TiO2 NPs (NP10) and NSs (NS78) were characterized by TEM, as shown in Fig. 1. The morphology of TiO2 NSs with 78% {001} facets (Fig. 1b) was different from that of TiO2 NPs with 10% {001} facets (Fig. 1a). According to Table 1, the shape of TiO2 changed from NPs to NSs with increasing RF. TiO2 with 61%, 71%, 74%, and 78% {001} facets were nanosheets, whereas those with 10% {001} facets were nanoparticles. The morphologies of TiO2 NS61, NS71, and NS74 were similar to that of NS78 (TEM pictures not shown).

Bottom Line: The results indicated that the addition of Cu(2+) enhanced agglomeration-sedimentation of TiO2, resulting in the reduction of TiO2 bioaccumulation by 10% to 26%.TiO2 nanoparticles (NPs) increased copper bioaccumulation by 9.8%, whereas the other four TiO2 nanosheets (NSs) decreased it by 43% to 53%, which depended on TiO2 variant adsorption and free Cu(2+) concentrations in the supernatant.This research highlighted the important role of the percentage of exposed {001} facets in nanostructured TiO2 on bioaccumulation and biotoxicity of TiO2 and Cu(2+) in Daphnia magna.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191, Beijing, P. R.China.

ABSTRACT
Anatase TiO2 nanosheets (NSs) with exposed {001} facets have been widely used because of their high activity and particular surface atomic configuration. However, investigations on their biotoxicity are rare. In this study, bioaccumulation of five different TiO2 (with 10%, 61%, 71%, 74% and 78% exposed {001} facets), as well as copper and enzyme activities in Daphnia magna, are systematically investigated and rationalized. The results indicated that the addition of Cu(2+) enhanced agglomeration-sedimentation of TiO2, resulting in the reduction of TiO2 bioaccumulation by 10% to 26%. TiO2 nanoparticles (NPs) increased copper bioaccumulation by 9.8%, whereas the other four TiO2 nanosheets (NSs) decreased it by 43% to 53%, which depended on TiO2 variant adsorption and free Cu(2+) concentrations in the supernatant. The levels of superoxide dismutase (SOD) enzyme and Na(+)/K(+)-ATPase activities suggested that oxidative stress, instead of membrane damage, was the main toxicity in D. magna. Meanwhile, the SOD enzyme activities increased with decreasing Cu accumulation and increasing Ti accumulation because of the different functions of Cu and Ti in organisms. This research highlighted the important role of the percentage of exposed {001} facets in nanostructured TiO2 on bioaccumulation and biotoxicity of TiO2 and Cu(2+) in Daphnia magna.

No MeSH data available.


Related in: MedlinePlus