three different measurements were taken: Id–Vds, Id–Vg, and realtime
current (shown in Fig. 10(a)). For the detection of live bacterial
cells, real-time current was recorded for devices incubated
with 105 cfu/mL E. coli bacteria. The addition of glucose into the
phosphate buffer saline hydrated device induced metabolization
and subsequent release of acidic metabolites (e.g. pyruvic, citric,
and lactic acid) from the living bacterial cells, thus changing the
pH near the electrode and causing a drop in the current