  Mycotoxins comprise a frequent type of toxins present in food and feed. The
problem of mycotoxin contamination has been recently aggravated due to the
increased complexity of the farm-to-fork chains, resulting in negative effects
on human and animal health and, consequently, economics. The easy-to-use,
on-site, on-demand, and rapid monitoring of mycotoxins in food/feed is highly
desired. In this work, we report on an advanced bioelectronic mycotoxin sensor
based on graphene field-effect transistors integrated on a silicon chip. A
specific aptamer for Ochratoxin A (OTA) was attached to graphene through
covalent bonding with the pyrene-based linker, which was deposited with an
electric field stimulation to increase the surface coverage. This
graphene/aptamer sensor demonstrates high sensitivity to OTA with the lowest
detection limit of 1.4 pM within a response time of 10 s which is superior to
any other reported aptamer-based methods.
