Comparison of Different Commercial Conducting Materials as Ion-to-Electron Transducer Layers in Low-Cost Selective Solid-Contact Electrodes

Abstract

Simple, robust, sensitive and low-cost all-solid-state ion-selective electrodes (SCISEs) are of interest in different fields, such as medicine, veterinary, water treatment, food control, environmental and pollution monitoring, security, etc.as a replacement for traditional ion-selective electrodes with liquid inner contact. In spite of their potential advantages, SCISEs remain mainly in the research laboratories. With the motivation of developing simple and low-cost SCISEs with possible commercial applications, we report a comparison study of six different commercial conducting materials, namely, polypyrrole-block-polycaprolactone (PPy-b-PCaprol), graphene/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) ink, poly(3,4-ethylenedioxythiophene):polyethylenglycol (PEDOT:PEG), high conductivity PEDOT:PSS, polyethylenimine (PEI) with PEDOT:PSS for their possible use as ion-to-electron transducer in polyurethane based pH-SCISEs. Among all studied pH-SCISES, PEDOT:PEG based electrodes exhibited the best results in terms of sensitivity, reproducibility and lifetime. Finally, these sensors were tested in different real samples showing good accuracy.

Determination of sodium and potassium ions in patients with SARS-Cov-2 disease by ion-selective electrodes based on polyelectrolyte complexes as a pseudo-liquid contact phase

“… 30 The conducting materials, in particular different polyelectrolytes, are used as ion-to-electron transducers primarily for creating solid contact ion-selective electrodes. 33 However, the application of classical solid contact sensors with ion-selective membranes for the medicine area is difficult due to the necessary miniaturization of the design of problems with the stability and reproducibility of the signal. 34 The most difficult problem in the design of ion-selective electrodes is the increase in the charge transfer resistance.…”

ISFET‐based ion sensors with photopolymerizable membranes

“…With the advent of solid-contact ion-selective electrodes with conducting polymers as a thermodynamically defined intermediate layer between a metal and a polymer membrane, [66] the attention of researchers turned to the development of this type of sensors, which are much easier to manufacture, much cheaper and can be used as disposable. [67,68,69] The second reason to be considered is the lack of a miniature reference electrode adequate for measurements with ISFET. In the already mentioned article by P. Bergveld, [12] it was pointed out that this is one of the first problems that must be solved to promote sensors of this type on the market.…”

Potentiometric Sensing

“…Ocana et al presented a comparative study of six different commercially available solid contact transducer materials in terms of their possible use for fabricating polyurethane­(PU)-based pH-selective electrodes . They compared polypyrrole- block -polycaprolactone, high conductivity PEDOT:PSS, graphene/PEDOT:PSS ink, PEDOT:polyethylenglycol, and polyethylenimine with PEDOT:PSS in their work.…”