Rapid advances in the usage of conducting, electroactive polymers (CEPs) in nanotechnology have now placed us in a position to study this versatile class of materials. Since it is known that inherently CEPs will continue to play a central role in the development of sophisticated devices, such as, electronic components, sensors, actuators, displays, smart windows, membranes, and catalysts. On other most obvious applications of CEPs depend on their conductivity and electroactivity [1]. Electrical conductivity and redox activity of CEPs can be also arranged or manipulated easily. Consequently, the desired properties for a specific application can be arranged by controlling the structure of the monomers, parameters of polymer formation processes and parameters of polymer usage conditions. However the development of highly conductive CEPs with adequate physicochemical and mechanical properties and chemical and thermal stabilities is not yet to be archived [2].

For the detection of various pesticides, biological receptors, especially enzymes that used in biosensors generally have well-known limitations, such as, low stability of biological species, difficulties of immobilization on substrates, leakage from substrate surface, high cost, and low chemical and thermal stabilities. Another disadvantage of enzyme biosensors is that the enzymes are not selective for one type target pesticide. Consequently, researches are nowadays condensed on solving of these problems, especially selectivity problems by using various mimetic receptors elements, such as MPcs. Studies in the literature indicate that MPc type sensors have generally showed their activity for the oxidation of the pesticides at anodic potentials or inhibition of the oxidation reaction of MPc with pesticides [3].

In this study, we designed conducting electroactive polymers (CEPs) based on metallophthalocyanines (MPcs) bearing electroactive and electropolymerizable substituents and to investigate usability of CEPs as selective, sensitive and stable electrochemical pesticide sensors. For this purpose, first of all MPcs bearing [[4-(2-morpholin-4-ylethoxy)benzyl]oxy] (Mor) [4-(diethylamino)phenyl]methylene-amino)-1-naphthyl]oxy] (DEA-MeA-Naf), [(4-morpholin-4-ylphenyl)methylene]amino)phenyl)ethoxy] (Mor-MeA) and [[4-morpholin-4-ylphenyl)methyleneamino)-1-naphthyl)oxy] (Mor-MeA-Naf)  substituents and Co²⁺,Mn³⁺ and TiO²⁺metal centers (MPcs-APSM) were synthesized and characterized. Then CEPs based electrodes by using MPcs-APSM with electropolymerization were designed and finally these electrodes as electrochemical pesticide sensors for the detection of most common used diazinon, eserine, parathion, carbaryl ve carbafuran pesticides were tested with various electrochemical and in-situ spectroelectrochemical analysis methods.

Electrochemical sensors designed here, sensed the target species by giving new signals (redox waves) at different potentials for different pesticides. Enhancement of the redox richness of MPcs-APSM based CEPs raised electrochemical applicability of the complex especially as selective, sensitive, and stable electrochemical pesticide sensors. 

Acknowledgement: This work is supported by the research fund of TUBİTAK (Project no: 114Z914) and Marmara University.

 References

1. Gerard M, Chaubey A, Malhotra B (2002) Biosens. Bioelectron. 17: 345-359.

2. Lyons M (2013) Electroactive Polymer Electrochemistry: Part 1: Fundamentals. Springer Science & Business Media

3. İpek Y, Dinçer H, Koca A (2014) J. Electrochem. Soc. 161: B183-B190.