The Complex Crystal of NaTCNQ–TCNQ Supported on Different Carbon Materials as Ion-to-Electron Transducer in All-Solid-State Sodium-Selective Electrode

Abstract

This work demonstrates the application of conductive organic crystals (7,7,8,8-tetracyanoquinodimethane (TCNQ) and its sodium salt (NaTCNQ)) supported on carbon nanomaterials (CNMs) as solid contact layer in all-solid-state ion-selective electrodes (ASS-ISEs). As ion-to-electron transductor between the ionically conducting membrane and the electronically conducting glassy carbon new layers based on a high capacity of charge transfer and a redox TCNQ/TCNQ− reaction are proposed. Developed CNM–NaTCNQ–TCNQ-contacted sensors provided a near to Nernstian response to sodium and excellent electrical parameters. The highest electrode capacitance was 2.15 mF, as the potential drift (and electrodes resistance) are significantly reduced due to the presence in solid contact combination of materials having ionic or electron conductivity. Moreover, the introduction of NaTCNQ in sodium-selective electrodes improves their selectivity toward to interfering cations. Carbon nanomaterials type used in the interlayer affects, in the different way, the analytical and electrical parameters of proposed ASS-ISEs. The possibility of improving the electrodes sensitivity, linear range and detection limit, by changing the NaTCQ:TCNQ ratio, is also presented.

Potentiometric Sensing

“…38 Later, the same group used a similar approach by combining carbon nanomaterials with TCNQ and its sodium salt to prepare an ion-to-electron transducer for solid-contact ISEs. 39 The possibility to improve the Na + -SEs sensitivity, linear range, and detection limit, by changing the NaTCNQ/TCNQ ratio was demonstrated in this work. Paczosa-Bator and co-workers also showed that reproducible standard potentials and low detection limits could be achieved for K + -and NO 3 − -SEs using the well-known charge transfer salt TTF-TCNQ as ion-to-electron transducer.…”

“…The improved potential stability and reproducibility of nitrate-selective electrodes were found to relate to the high double layer capacitance of graphene and the presence of the TTF/TTF + redox couple . Later, the same group used a similar approach by combining carbon nanomaterials with TCNQ and its sodium salt to prepare an ion-to-electron transducer for solid-contact ISEs . The possibility to improve the Na + -SEs sensitivity, linear range, and detection limit, by changing the NaTCNQ/TCNQ ratio was demonstrated in this work.…”

Potential Reproducibility of Potassium-Selective Electrodes Having Perfluorinated Alkanoate Side Chain Functionalized Poly(3,4-ethylenedioxytiophene) as a Hydrophobic Solid Contact

“…18 Recently various new SCs have also grown in popularity, such as tetrathiafulvalene (TTF) 19 and 7,7,8,8-tetracyanoquinodimethane (TCNQ) and their radical salts, 20 intercalation compounds (LiFePO 4 /FePO 4 ), 21 Prussian blue analogues, 22 KBr/AgBr, 23 fullerenes, 24 submicron porous carbon spheres, 25 gold nanoparticles, 26,27 molybdenum disulfide, 28 metal–organic frameworks (MOF), 29 and different types of composite materials. 30−37…”

“…solid contacts (SC), have been until now electrically conducting polymers (ECP), − different carbon materials with large capacitance, − redox couples, , and redox-active compunds . Recently various new SCs have also grown in popularity, such as tetrathiafulvalene (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) and their radical salts, intercalation compounds (LiFePO 4 /FePO 4 ), Prussian blue analogues, KBr/AgBr, fullerenes, submicron porous carbon spheres, gold nanoparticles, , molybdenum disulfide, metal–organic frameworks (MOF), and different types of composite materials. − …”

Ruthenium dioxide nanoparticles as a high-capacity transducer in solid-contact polymer membrane-based pH-selective electrodes

“…Various electroactive materials such as conducting polymers [9] and organic conducting crystals [10] which exhibit high redox capacitance, as well as nanomaterials transducers [11] (such as microfibers, microspheres, nanoparticles and microcapsules), nanoporous gold [12] and carbon black [13, 14] characterized by a high double layer capacitance have been already used as internal layers. Metal oxides also appeared to improve electrodes’ properties.…”