Total RSH and GSH content in <i>E. coli</i> overexpressing GSH biosynthesis genes.

<p>Cellular RSH (after 4 h IPTG induction, A) and GSH levels (B) after 4 h (white) or 16 h (striped) IPTG induction were determined in <i>E. coli</i> AG1 (wt), AG1/pCA24N<i>gshA</i> (<i>gshA</i>) and AG1/pCA24NgshB (<i>gshB</i>) cells (n = 3). *p<0.05; **p<0.005.</p

Elemental analysis of purified nano-sized structures.

<p>Cd and Te content (ppm) in purified NPs from cells exposed only to CdCl₂ (Cd) or CdCl₂/K₂TeO₃ (CdTe) were determined as described in Methods; bd stands for below detection limit.</p

Particle purification and size determination.

<p><b>A,</b> UV-exposed cell suspensions of <i>E. coli</i> AG1/pCA24N<i>gshA</i>, untreated or exposed to CdCl₂ or CdCl₂/K₂TeO₃ (from left to right). <b>B,</b> purified fractions exposed to UV light. <b>C</b> and <b>D</b>, DLS particle size determination of fluorescent samples from cells exposed to CdCl₂ or CdCl₂/K₂TeO₃, respectively.</p

Cd and Te content of <i>E. coli</i> expressing <i>gshA</i> or <i>gshB</i> genes.

<p>Cd and Te content (%) was determined in fluorescent and non-fluorescent cells after metal exposure. Conditions in which fluorescent cells were observed are indicated in bold numbers; bd and nd stands for below detection limit and not determined, respectively.</p

Effect of temperature, microaerophilic conditions and citrate on <i>E. coli</i> fluorescence.

<p>UV-exposed <i>E. coli</i> AG1/pCA24N<i>gshA</i> cells previously incubated under NP biosynthesis conditions with some modifications: 1, control (37°C); 2, increased incubation temperature (42°C); 3, reducing agent (citrate buffer pH 7.0); 4, microaerophilic conditions.</p

XRD pattern of biosynthesized CdTe QDs.

<p>CdTe NPs were purified from <i>E. coli gshA</i> cells as described in Methods and the presence of crystalline structures analyzed by XRD.</p

Absorbance and fluorescence spectra of purified NPs.

<p><b>A</b>, absorption spectra of NPs from unexposed (solid black line), exposed to CdCl₂ (dashed grey line) or CdCl₂/K₂TeO₃ (dashed black line) cells. <b>B</b> and <b>C</b>, emission spectra of NPs from cells exposed to CdCl₂ or CdCl₂/K₂TeO_3, respectively.</p

Fluorescence assessment in <i>E. coli</i> overexpressing <i>gshA</i> or <i>gshB</i> genes.

<p>UV light-exposed cell pellets of <i>E. coli</i> AG1/pCA24N<i>gshA</i> (A) or AG1/pCA24N<i>gshB</i> (B) that were untreated (1) or exposed to CdCl₂ (2), K₂TeO₃ (3) or CdCl₂/K₂TeO₃ (4).</p

Fluorescence microscopy of <i>E. coli</i> exposed to Cd and Te salts.

<p><i>E. coli</i> AG1/pCA24N<i>gshA</i> treated with CdCl₂ and K₂TeO₃ was analyzed by epifluorescence microscopy. Circles indicate structures where fluorescence is accumulated. A, left image: phase contrast (PC); central image: monochromatic fluorescence (F) after excitation using UV-DAPI/FITC filter; right image: merge. B, left image: magnification phase contrast (PC); left image: merge. C, fluorescence microscopy under UV light exposure.</p

IR spectra of CdTe-GSH NPs and GSH.

<p>IR spectra of CdTe-GSH NPs and GSH.</p