Carbon Nanotube-Based Sensor Platform for Bioelectronic Nose - Bioelectronic Nose: Integration of Biotechnology and Nanotechnology - page 228

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Fig. 12.8 Canine receptor-based bioelectronic nose. a Schematic diagram showing the sensing
mechanism for the detection of hexanal using a canine receptor-based bioelectronic nose. The
binding of hexanal to canine receptors results in a Ca 2+ influx into the nanovesicles through Ca 2+
channels. Here, the accumulated Ca 2+ ions inside the nanovesicles create a positive gate-potential
in the vicinity of underlying CNTs, and the increased potential results in the decrease of the con-
ductance in the CNT channel. b Real-time conductance measurement data obtained from a canine
receptor-based bioelectronic nose after the introduction of hexanal. The conductance decreased
after the introduction of a hexanal solution with a femtomolar concentration. c Response curve of
canine receptor-based bioelectronic nose to hexanal with different concentrations. The responses
of the bioelectronic noses were fitted to the Langmuir isotherm curve ( red solid curve ). d Real-
time conductance measurement data obtained from a canine receptor-based bioelectronic nose
after the injection of different odorants. The addition of 1 nM heptanal, octanal, pentanal and
hexanol solutions had no effect on the conductance of the sensor, while the addition of 1 pM
hexanal solution caused a sharp decrease in the conductance of the sensor. e Graph showing the
conductance changes in canine receptor-based bioelectronic noses after the introduction of spoiled
milk. A canine receptor-based bioelectronic nose showed conductance changes after the introduc-
tion of spoiled milk ( black line ). No significant conductance change was observed in the case of