Cholinesterase Biosensors Based on Screen‐Printed Electrodes Modified with Co‐Phtalocyanine and Polycarboxylated Thiacalixarenes

Abstract

New acetylcholinesterase biosensors have been developed on the base of screen-printed electrodes modified with Co-phtalocyanine and polycarboxylated thiacalixarenes as enzyme support. The biosensors showed improved operational and analytical characteristics and high accuracy of the signal measurement. The biosensors developed made it possible to detect 3-200 ppb of paraoxon and 1-50 ppb of malaoxon with detection limits down to 2 and 0.05 ppb, respectively (incubation time: 15 min). The influence of macrocyclic receptors was related to nonenzymatic accumulation of the analytes within the surface layer and electrostatic interactions with remaining free carboxylic groups of the support. The reliability of the inhibition measurements was confirmed by testing spiked samples of sparkling and tape waters. were determined in 15 min incubation step with very low matrix effect in spiked tap and mineral water. -The steric limitations and specific interactions with the substrate and inhibitors specify the positive effect of macrocycles and their structure influence on the biosensor characteristics.

Acetylcholinesterase Sensor Based on Polyelectrolyte Complexes with DNA Inclusion for the Determination of Reversible Inhibitors

“…They form rounded particles evenly distributed on the surface of 20–50 nm. The efficiency of this mediator in thiocholine oxidation was confirmed elsewhere and allowed significant decrease of the working potential.…”

Acetylcholinesterase biosensor for inhibitor measurements based on glassy carbon electrode modified with carbon black and pillar[5]arene

“…The CB quantities meet full coverage of the surface and maximal mechanical stability of the layer. The concentrations of AChE taken for immobilization correspond to those previously tested for similar biosensor based on carbon nanotubes [27]. Variation of the P [5]A concentration showed optimal response at 0.2 nM of modifier per electrode, i.e.…”

“…For these reasons, various mediators were tested to decrease the working potential of the AChE biosensors and avoid electrode poisoning. Metallocyanate complexes [23][24][25], tetracyanoquinodimethane [26], and Co phtalocyanine [27,28] are mostly described for this purpose. They can be also combined with hydrophilic polymers like chitosan and carbonaceous nanomaterials (carbon nanotubes, carbon black (CB), graphene) that establish the functions of enzyme stabilization and its electric wiring.…”

Biosensors as tools of environmental monitoring for organophosphorus nerve agents

“…In this time, the staff members of the university published many articles on this subject matter in both Russian and foreign periodicals. Works of considerable current interest in this area were dedicated to electrochemical biosensors based on cholinesterase for the determina tion of organophosphorus pesticides [14,15]. Dhull et al [16] surveyed the technical characteristics of electrochemical biosensors and prospects for their improvements.…”