Figure Legends
Figure 1. (a) Miniaturised electrochemical silicon chip integrating 4 layout of EC cells with three planar microelectrodes made in Pt (WE) and Au (CE and RE). Table 2 reports the electrodes dimensions; (b) whole portable system EC-reader connected to the PC; (c) details of the portable system EC-reader: electrochemical silicon chip connected to the reading board
Figure 2. (a) Electrochemical response (SW current intensities) of EC-Cells at various Os redox probe amount; (b) linear interpolation of current intensities versus Os amount; (c) Correlation of Sensitivity/WE area; (d) Correlation of Sensitivity/WE-CE distance. The error bars represent the standard deviation from a triplicate.
Figure 3. (a) Details of the EC cell used for the sensing; (b) Principle of the biochemical method based on whole-cell sensing using the engineered E. colias sensing element.
Figure 4. (a) CV curves of arsenic sensitive E. coli strain in presence of AsIII at 0 (black line), 2.5ppb (red line), 10ppb (blue line), 50 ppb (green line) and 100 ppb (orange line) and relative current increase (blue dashed arrow). Inset: detail of PAP peak voltage shift (green dashed arrow); (b) CV trend for E. coli samples induced by AsIII in water; (c) calibration curve calculated at 2.5 ppb to 50 ppb of AsIII. The error bars represent the standard deviation from a triplicate.
Figure 5. (a) CV curves of E. coli cells in presence of HgII at 0 (black line), 2.5ppb (red line), 5 ppb (yellow line), 10ppb (blue line) and 50 ppb (green line); (b) CV curves of E. coli cells in presence of CdII at 0 (black line), 2.5ppb (red line), 5 ppb (yellow line), 10ppb (blue line) and 50 ppb (green line); (c) comparison of PAP current values measured on E. coli samples (specific for AsIII) treated with different concentration of AsIII (green line), HgII (red line) and CdII (blue line). The error bars represent the standard deviation from a triplicate.
Figure 6. (a) CV trend of mercury sensitive E. coli strains induced by 0.25 ppb; 1 ppb; 2.5 ppb; 10 ppb HgII in water: the insert shows a calibration curve calculated for the low range concentration (0.25 ppb to 2.5 ppb) of HgII in water. (b) comparison of PAP current values measured on E. coli samples (specific for HgII) treated with different concentration of AsIII (green line), HgII (red line) and CdII (blue line). The error bars represent the standard deviation from a triplicate.