Biosensors for environmental applications Future development trends*
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INTRODUCTION
Public concern and legislation are nowadays demanding better environmental control. In addition, the
increase in the number of analytes to monitor requires more suitable analytical methods. For conventional
“off-site” analysis, samples need to be sent to a laboratory for testing. Conventional methods are
actually reaching the highest accuracy with low detection limits, but are expensive, time-consuming,
and require the use of highly trained personnel [1]


BIOSENSOR CONFIGURATIONS
Biosensors are usually classified into various basic groups, according to the signal transduction and to
the biorecognition principles. On the basis of the transducing element, biosensors can be categorized as
electrochemical, optical, piezoelectric, and thermal sensors. The electrochemical biosensors, and
among them the amperometric and the potentiometric ones, are the best described in the literature; those
based on optical principles are the next most commonly used transducers. In fact, most catalytic biosensors
are based on electrochemical methods, whereas affinity biosensors have generally proved more
amenable to optical detection methods [7].


ENVIRONMENTAL APPLICATIONS
In the following section, we describe biosensors developed for environmental monitoring, considering
first, biosensors that measure an effect such as toxicity and endocrine effect biosensors and second,
biosensors that detect a compound or a group of compounds based on the specific recognition of a biomolecule.
A wide range of compounds of environmental concern or under suspicion are being considered
for biosensor development. Table 1 lists examples of these reported biosensors for different environmental
applications.