ABSTRACT
The principal biological role of cholinesterase enzyme (AChE) is the termination of the nervous impulse transmission at cholinergic synapses by rapid hydrolysis of the neurotransmitter acetylcholine. Early investigations indicated that the active site of AChE contains two sub-sites, the esteratic and anionic sub-sites, corresponding to the catalytic site and the cholinebinding pocket, respectively (Arduini et al. 2010 and reference therein). A serine residue of the esteratic site accounts for the substrate complexation but it may be also subjected to inhibition by some of the most common pesticides. In particular, organophosphate and carbamate pesticides are powerful neurotoxins that irreversibly inhibit the activity of AChE by modifying the catalytic serine residue. Taking into consideration this inhibition property, several innovative solutions for the sensitive detection of organophosphate and carbamate pesticides have been proposed. Some examples of these investigations will be reviewed, mainly focusing on biosensors obtained by covalent immobilization of AChE onto a SAM gold electrode.
