Iron concentration (M)

Experience condition

Soluble extracellular

Absorbed at cell surface

Intracellular

Positive control

8.1 × 106 ± 0.01

5.4 × 106 ± 0.01

6.7 × 106 ± 0.01

Culture with Fe/SiO2 104 M

4.3 × 105 ± 0.01

3.9 × 105 ± 0.01

1.6 × 105 ± 0.01

Iron released from the SiO2 capsule

Molar unit

3.5 × 105 ± 0.01

3.4 × 105 ± 0.01

9 × 106 ± 0.01

%

35.6

34.6

9.5