7 research outputs found
Thin-section TEM Images of <i>S. oneidensis</i> MR-1.
<p>A. without particles, B. plain 13 nm gold Nanoparticles, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016634#pone-0016634-g004" target="_blank">Fig. 4Cβ4D</a>. Chromate coated gold nanoparticles, Cr-AuNp:13 nm, (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016634#pone-0016634-g004" target="_blank">Fig. 4Eβ4F</a>) 3.5 nm Cr-AuNp. Red arrows indicate extracellularly bound Cr-AuNp and green arrows/circle indicate internalized particles. (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016634#pone-0016634-g004" target="_blank">Fig. 4Gβ4H</a>) show 3.5 nm and 13 nm probes used in Cr-AuNp preparation.</p
Effect of Cr-AuNPs on the growth of <i>Shewanella oneidensis</i> MR-1.
<p>Either 3.5 nm (closed symbols) or 13 nm (open symbols) Cr-AuNPs were added to wells at volumes of 0, 5, 10, and 50 Β΅l. Error bars represent the standard error from three independent cultures.</p
Confocal Raman Mapping.
<p>Raman Intensity Maps averaged over a wide wavenumber region (162β1953 cm<sup>β1</sup>) covering most of bio-molecular components in cells to obtain a Raman chemical image of the cell (A), Phonon Plasmon peak (207β297 cm<sup>β1</sup>) originating from gold depicting the presence of Cr-AuNps (B), Cr(VI) - hexavalent chromium (C, 837β873 cm<sup>β1</sup>), reduced non-toxic trivalent Cr(III) (D, 531β567 cm<sup>β1</sup>). Raman images in grid format, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016634#pone-0016634-g006" target="_blank">Fig. 6E and 6F</a> are representations of 6B and 6C respectively. 6-E* and F* represent magnified pixel plots to demonstrate the overlap in signal of Au and Cr(VI) peaks within cells.</p
Inductively Coupled Mass-Spectrometry.
<p>A. ICP-MS Calibration curve for Cr quantification. B. Intracellularly trapped Cr(VI) and Cr(III) at time tβ=β0 and tβ=β12 h after Cr-AuNp treatment.</p
Confocal Fluorescence Lifetime Imaging.
<p><i>S. oneidensis</i> MR-1 incubated with 3.5 nm (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016634#pone-0016634-g007" target="_blank">Fig. 7A & 7C</a>) and 13 nm (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016634#pone-0016634-g007" target="_blank">Fig. 7B & 7D</a>) Cr-AuNp probes show scattered low-lifetime (blue) distribution indicating the presence of gold nanoparticles (both internalized and externally bound) compared to the control incubated with plain gold nanoparticles (inset - 7A).</p
Effect of Cr-AuNPs on chromate reduction by <i>S. oneidensis</i> MR-1.
<p>Abiotic controls were included to rule out the reduction of chromate by media components and the Cr-AuNPs (open symbols). There was no adverse effect on chromate reduction ability induced by the nanoparticles (closed symbols). In addition, the nanoparticles did not directly reduce the chromate in the medium in the absence of cells (open symbols). Error bars represent the standard error from three independent cultures.</p
Schematic Illustration.
<p>Representation of passive uptake of Cr-AuNPs by <i>S. oneidensis</i> MR-1 and subsequent Raman Chemical imaging of cells to reveal the intracellular localization of reduced Cr(III) and unreacted Cr(VI).</p