  Bio-inspired molecular communications (MC), where molecules are used to
transfer information, is the most promising technique to realise the Internet
of Nano Things (IoNT), thanks to its inherent biocompatibility,
energy-efficiency, and reliability in physiologically-relevant environments.
Despite a substantial body of theoretical work concerning MC, the lack of
practical micro/nanoscale MC devices and MC testbeds has led researchers to
make overly simplifying assumptions about the implications of the channel
conditions and the physical architectures of the practical transceivers in
developing theoretical models and devising communication methods for MC. On the
other hand, MC imposes unique challenges resulting from the highly complex,
nonlinear, time-varying channel properties that cannot be always tackled by
conventional information and communication tools and technologies (ICT). As a
result, the reliability of the existing MC methods, which are mostly adopted
from electromagnetic communications and not validated with practical testbeds,
is highly questionable. As the first step to remove this discrepancy, in this
study, we report on the fabrication of a nanoscale MC receiver based on
graphene field-effect transistor biosensors. We perform its ICT
characterisation in a custom-designed microfluidic MC system with the
information encoded into the concentration of single-stranded DNA molecules.
This experimental platform is the first practical implementation of a
micro/nanoscale MC system with nanoscale MC receivers, and can serve as a
testbed for developing realistic MC methods and IoNT applications.
