Huang et al. (2011) demonstrated a graphene-based biosensor
that can detect the metabolic activities of live bacterial cells in real
time. Such simple, rapid and label-free biosensors demonstrate the
ability to distinguish live and dead cells and can be used for high
throughput screening of antibacterial drugs. CVD grown graphene
was functionalized with a linker molecule and incubated with antiE.
coli O and K antibody. The device was incubated with ethanolamine
and Tween 20 to passivate the unreacted linker molecules
and uncoated graphene, respectively. Different concentrations of
E. coli solution were added to the device. The attachment of bacteria
by antibodies was monitored by taking Id–Vds and FET transfer
curves (Id–Vg) before and after each incubation of E. coli bacteria
from 0 to 105 cfu/mL (Fig. 9). Incubation of device with
Pseudomonas aeruginosa did not produce a significant change in
response of FET, indicating the high specificity of detection. To
evaluate and confirm device pH sensitivity, the device was incubated
with different pH buffer solutions (pH 3–11, odd only) and