membrane reactor or biocatalytic membrane were operated in a lab-scale and batch
mode. This underlines the fact that bioremediation technology with nanobiocatalysts
is still under development. Only one pilot experiment has been performed so far; it
will be described in the following chapters of this book (Gasser et al. 2014).
16.8 Nanobiosensors
Enzymes immobilized onto nanomaterials can be used for designing biosensors that
can be applied for the detection of various micropollutants in the environment. A
biosensor is a device for the selective detection of analytes that combines a biological component such as an enzyme and a physicochemical detector associated with
electronics and a signal processing system. Biosensors can be considered a complementary tool to classical analytical methods that include gas and liquid chromatography. Most biosensors are based on an electrochemical principle that employs redox
reactions in order to quantify the amount of an analyte. Electrochemical biosensors
can be categorized as potentiometric, amperometric, and conductometric. A potentiometric biosensor measures oxidation or reduction potential of an electrochemical
reaction using an indicator electrode and a reference electrode. An amperometric
biosensor is based on the measurement of current as a function of time resulting from
the oxidation and reduction of an electroactive species in a biochemical reaction that
mainly depends on the concentration of an analyte with a fixed potential. A conductometric biosensor measures changes in the ionic strength, and thus the conductivity
of the solution between two electrodes as a result of an enzymatic reaction (Perumal
and Hashim 2014). Common biosensors are based on cells or enzymes bound to the
surface of a membrane or an electrode. These biosensors have been tested for the
detection of heavy metals, phenolic compounds like pesticides, herbicides, and
pharmaceuticals in wastewater samples and soil and many of them have been
reviewed by Nigam and Shukla (2015) and Rebollar-Pérez et al. (2015).
A large number of nanobiosensors have been developed and tested over the past
5 years (Table 16.2). They have been constructed of diverse nanomaterials ranging
from nanoparticles, nanotubes, nanorods, nanowires, graphene nanosheets, and
various hybrid nanocomposites. Nanomaterials incorporated in the biosensors represent a new approach with unique features, which were summarized by Malik et al.
(2013) and Hammond et al. (2016). High selectivity, low detection limits, simplicity,
relatively low cost, and reproducibility represent the most promising properties of
nanobiosensors. Nanobiosensors are nowadays under development, and especially
laccase, tyrosinase, and acetylcholinesterase have been tested for the detection of
pesticides and phenolic compounds. The interest in enzyme-based biosensors has
significantly increased thanks to the properties, which can extend the range of
applications utilizing nanobiocatalysts.
362
M. Čvančarová et al.
mode. This underlines the fact that bioremediation technology with nanobiocatalysts
is still under development. Only one pilot experiment has been performed so far; it
will be described in the following chapters of this book (Gasser et al. 2014).
16.8 Nanobiosensors
Enzymes immobilized onto nanomaterials can be used for designing biosensors that
can be applied for the detection of various micropollutants in the environment. A
biosensor is a device for the selective detection of analytes that combines a biological component such as an enzyme and a physicochemical detector associated with
electronics and a signal processing system. Biosensors can be considered a complementary tool to classical analytical methods that include gas and liquid chromatography. Most biosensors are based on an electrochemical principle that employs redox
reactions in order to quantify the amount of an analyte. Electrochemical biosensors
can be categorized as potentiometric, amperometric, and conductometric. A potentiometric biosensor measures oxidation or reduction potential of an electrochemical
reaction using an indicator electrode and a reference electrode. An amperometric
biosensor is based on the measurement of current as a function of time resulting from
the oxidation and reduction of an electroactive species in a biochemical reaction that
mainly depends on the concentration of an analyte with a fixed potential. A conductometric biosensor measures changes in the ionic strength, and thus the conductivity
of the solution between two electrodes as a result of an enzymatic reaction (Perumal
and Hashim 2014). Common biosensors are based on cells or enzymes bound to the
surface of a membrane or an electrode. These biosensors have been tested for the
detection of heavy metals, phenolic compounds like pesticides, herbicides, and
pharmaceuticals in wastewater samples and soil and many of them have been
reviewed by Nigam and Shukla (2015) and Rebollar-Pérez et al. (2015).
A large number of nanobiosensors have been developed and tested over the past
5 years (Table 16.2). They have been constructed of diverse nanomaterials ranging
from nanoparticles, nanotubes, nanorods, nanowires, graphene nanosheets, and
various hybrid nanocomposites. Nanomaterials incorporated in the biosensors represent a new approach with unique features, which were summarized by Malik et al.
(2013) and Hammond et al. (2016). High selectivity, low detection limits, simplicity,
relatively low cost, and reproducibility represent the most promising properties of
nanobiosensors. Nanobiosensors are nowadays under development, and especially
laccase, tyrosinase, and acetylcholinesterase have been tested for the detection of
pesticides and phenolic compounds. The interest in enzyme-based biosensors has
significantly increased thanks to the properties, which can extend the range of
applications utilizing nanobiocatalysts.
362
M. Čvančarová et al.