Acetylcholinesterase AChE-based biosensors

Biosensors may provide the basis for in-field analyses and real-time process analysis. However, biosensors are generally limited to the determination of a limited range of analytes in defined matrices. Enzyme-based biosensors, principally acetylcholinesterase (AChE) inhibition, have been successfully used in environmental analysis for residues of dichlorvos and paraoxon, " carbaryl " and carbofuran. " Immunochemically based biosensors may be the basis for the determination of pesticide residues in liquid samples, principally water and environmental samples, but also fruit juices. The sensors can be linked to transducers, for example based on a piezo-... 

Acetylcholinesterase (AChE) isolated from various organisms has been used in the majority of pesticide biosensors. In the early 1950s potentiometric detection was adopted for pesticide detection. In the middle of the 1980s it was used for the construction of the first integrated biosensors for detection of pesticides based on inhibition of AChE. Later rapid changes in science and technology introduced novel genetically... 

The aim of this chapter is to review some basic concept concerning the electrochemical biosensors and to illustrate a protocol for the detection of environmental organic pollutants on the basis of electrochemical biosensors. In particular, a method based on the inhibition of the enzyme acetylcholinesterase (AChE) for the detection of organophosphorus and carbamate pesticides will be described in detail. 

In living beings, these pesticides bind irreversibly to the active site of acetylcholinesterase (AChE) - enzyme involved in the transmission of nerve impulse. Electrochemical biosensors for measurement of these pesticides are based all on the inhibition of AChE and the inhibition degree is proportional to the pesticide concentration. 

In the following section an example of the use of disposable graphite sensor based for food analysis will be described. In particular, the use of these sensors to develop enzymatic biosensors for pesticide detection based on AChE (acetylcholinesterase) enzyme inhibition will be described. 

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