ABSTRACT
Recently, conventional techniques for the analysis of heavy metals
have undergone rapid development and have been applied to the
risk management of foods and the environment, as they have
for other environmental pollutants. For example, graphite furnace
atomic absorption spectrometry (GF-AAS), inductively coupled
plasma mass spectrometry (ICP-MS), inductively coupled plasma
atomic emission spectrometry, and X-ray fluorescence spectroscopy
are extremely precise analytical techniques and enable the detection
of heavy metals with high sensitivity and selectivity.2,3 However,
these methods require expensive instruments with high running
costs, time-consuming processes, and expert techniques. Therefore,
they are disadvantageous for primary comprehensive monitoring
and the on-site analysis of heavy metals in various food and
environmental samples. On the other hand, biosensors are ideal
tools to fulfill these requirements, because they have the advantages
of portability, low cost, ease of use, and rapid responses in real time,
even if their sensitivity and selectivity are lower than those of the
above-mentioned conventional methods.4,5
As is well known, biosensors are analytical devices consist-
ing of biological materials in conjunction with a compatible
transducer. Biomaterials are quantitatively responsible for the
specific recognition of target analytes. Because living organisms
have adapted to heavy metal poisoning during phylogenic evolution,
they respond to heavy metals through various biochemical and
physiological processes, thereby acquiring tolerance against them.
These systems are strictly regulated at the transcriptional, trans-
lational, and post-translational levels. Therefore, the mechanisms
underlying the response and adaptation to heavymetals enable us to
develop useful biosensors. The transducers convert signals obtained
by the interaction of the biomaterials with the analytes to various
outputs, which include amplified physicochemical signals such as
amperometric, potentiometric, optical, and thermal signals.
