A simple approach for fabricating solid-contact ion-selective electrodes using nanomaterials as transducers

Abstract

A general method for fabricating nanomaterials based solid-contact ISEs is developed. The mixture of an ionic liquid and a nanomaterial is used as intermediate layer.The detection limits of the proposed sensors are in the nanomolar range. The developed electrodes exhibit a good response time and excellent stability. A simple and robust approach for the development of solid-state ion-selective electrodes (ISEs) using nanomaterials as solid contacts is described. The electrodes are fabricated by using the mixture of an ionic liquid (IL) and a nanomaterial as intermediate layer, formed by melting the IL. Tetradodecylammonium tetrakis(4-chlorophenyl)borate (ETH 500) is chosen as an model of IL to provide strong adhesion between the inner glassy carbon electrode and the intermediate layer. Nanomaterials including single-walled carbon nanotubes (SWCNTs) and graphene were used as active ion-to-electron transducers between the glassy carbon electrode and the ionophore-doped ISE membrane. By using the proposed approach, the solid-contact Cu 2+ -and Pb 2+ -selective electrodes based on ETH 500/SWCNTs and ETH 500/ graphene as transducers, respectively, have been fabricated. The proposed electrodes show detection limits in the nanomolar range and exhibit a good response time and excellent stability.

Development of Miniature Solid Contact Ion Selective Electrodes for in situ Instrumentation

“…[d] Ping et al., Electrochem Comm (2011) (GO only). [e] calculated from Liang et al., Analytica Chimica Acta (2015) …”

“…The ionic liquid pellet with single‐wall carbon nanotubes (ETH‐CNT) layer was prepared by mixing tetradodecylammonium tetrakis(4‐chlorphenyl) borate (ETH500) with single walled carbon nanotubes (SWCNT), both purchased from Sigma Aldrich, at a 15 : 1 wt/wt ratio as reported by Liang et al. .…”

“…Incorporating CNTs as a solid contact layer often involves functionalization procedures in order to disperse the CNTs in solution to allow uniform application via drop casting or other solvent deposition methods . Another approach, that does not require a functionalization step, used a powdered mixture of CNTs and an ionic liquid that were melted onto the surface of a glassy carbon rod . In addition to eliminating the need for functionalization, this procedure resulted in a more secure connection between the solid‐contact layer and the electrical conductor, which could lead to a more stable and robust electrode.…”

Robust fabrication of nanomaterial-based all-solid-state ion-selective electrodes

“…The ionic liquid, tetradodecylammonium tetrakis(4-chlorophenyl)borate (ETH 500), was used as binder. 18 Nevertheless, ETH 500 binder might also effect the original electroconductivity of nanomaterials since ETH 500 is not a room-temperature ionic liquid.…”

Novel Screen-Printed All-Solid-State Copper(II)-Selective Electrode for Mobile Environmental Analysis

“…There are recent reports on ASS copper(II) electrodes [26]- [29]. These electrodes are mainly based on graphite pastes and expensive nanomaterials.…”