SUPPORTING INFORMATION

Colloidal stability and toxicity of gold nanoparticles and gold chloride on Chlamydomonas reinhardtii

Renata Behra1,2, *, Bettina Wagner1, Linn Sgier1, David Kistler1

1Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Environmental Toxicology, Dübendorf, Switzerland

2ETH-Zürich, Institute of Biogeochemistry and Pollutant Dynamics, Zürich, Switzerland

*Tel. +41 58 765 51 19; Fax: +41 58 765 53 11; E-mail:

Table S1. Size and Zeta potential of AuNPcar (batch 2)Page ii

Table S2. Stability of AuNPcar in Talaquil and Chriesbach waterPage iii

Table S3.Stability of AuNPcit in Talaquil and Chriesbach waterPage iv

Figure S1. Zeta potential of AuNPcar as function of average size in MOPS.Page v

Figure S2. Effect of AuNPcarb and AuNPcit on photosynthetic yieldPage vi

Figure S3. Effect of 10 µM AuNPcarb on algal growthPage vii

AuNPcar
(µM) / mean size
(nm) / stdev / PDI / ZP
(mV) / stdev
10 / 74 / 18 / 0.6 / -12.0 / 1.7
50 / 76 / 5 / 0.7 / -21.5 / 0.6
100 / 63 / 4 / 0.5 / -26.0 / 1.7
250 / 55 / 2 / 0.4 / -28.8 / 1.9

Table S1.Mean particle diameter,polydispersity index (PDI) and zeta potential (ZP) of AuNPcar (batch 2) measured by DLS one hour after dilution of the stock solution (250 µM Au)in 10 mM MOPS, pH 7.5. The standard deviation of three analytical replicates are indicated.

Talaquil / Chriesbach
Time (h) / size
(nm) / stdev / PDI / ZP
(mV) / stdev / size
(nm) / stdev / PDI / ZP
(mV) / stdev
1 / 73 / 3 / 0.6 / -17.5 / 2.1 / 117 / 49 / 0.6 / -13.5 / 1.2
2 / 120 / 8 / 0.7 / -18.4 / 1.7 / 101 / 26 / 0.6 / -12.3 / 0.9
24 / 95 / 9 / 0.7 / -19.5 / 1.1 / 122 / 72 / 0.6 / -11.5 / 0.1

Table S2. Mean particle diameter, polydispersity index (PDI) and zeta potential (ZP) of 10 µM AuNPcar measured by DLS after dilution of the stock solution as function of time in Talaquil and Chriesbach water. The standard deviation of three analytical replicates are indicated.

Talaquil / Chriesbach
Time (h) / size
(nm) / stdev / PDI / ZP
(mV) / stdev / size
(nm) / stdev / PDI / ZP
(mV) / stdev
1 / 480 / 153 / 0.4 / -8.2 / 2.3 / 263 / 22 / 0.4 / -12.6 / 0.5
2 / 346 / 65 / 0.5 / -13.7 / 1.8 / 459 / 9 / 0.4 / -12.5 / 0.7
24 / 317 / 14 / 0.4 / -14.1 / 2.1 / 639 / 10 / 0.5 / -12.7 / 0.3

Table S3. Mean particle diameter, polydispersity index (PDI) and zeta potential (ZP) of 10 µM AuNPCitr measured by DLS after dilution of the stock solution in 10 mM MOPS, pH 7.5, and as function of time in Talaquil and in Chriesbach water. The standard deviation of three analytical replicates are indicated.

Figure S1. Zeta potential of AuNPcar (batch 1) in MOPS as function of the average size for the tested concentrations of 250, 100, 50, 10 and 5 µM Au (from left to right). Data are taken from Table 1.

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FigureS2. Effects of AuNPcar (a and b) and AuNPcit(c) on the photosynthetic yield in the wildtype (a and c), and the cell wall free mutant (b) after 1 and 2 h exposure in MOPS. Data points represent the mean of 2 replicates in one typical experiment. Error bars lie within the dots.

Figure S3. Effects of 10 µM AuNPcarb on growth of the wildtype (a) and the mutant (b) of C. reinhardtii. The standard deviation of 2 technical replicates are shown. Control algae (♦), exposed algae (■).

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