All-Solid-State Polymeric Membrane Ion-Selective Miniaturized Electrodes Based on a Nanoporous Gold Film as Solid Contact

Abstract

ABSTRACT:A new type of all-solid-state polymeric membrane ion-selective electrodes (ISEs) is developed by using a nanoporous gold (NPG) film as solid contact. The NPG film is in situ formed on the surface of a gold wire electrode by the multicyclic electrochemical alloying/dealloying method. The characteristics of the NPG film, such as the large surface area, high double layer capacitance, and good conductivity, have been demonstrated by cyclic voltammetry and electrochemical impedance spectroscopy. The NPG film offers a well-defined interface between the electronic conductor and the ion-selective membrane. The NPG filmbased all-solid-state K + ISE shows a stable Nernstian response within the concentration range from 10 −6 to 10 −2 M, and the detection limit is 4.0 × 10 −7 M. The proposed electrode exhibits an improved potential stability with a reduced water layer in comparison with the coated-wire K + -ISE, which is due to the bicontinuous electron-and ion-conducting properties of the ionophore-doped polymeric membrane/NPG film interlayer. Unlike the additionally coated intermediate layers as single-use solid contacts, the in situ formed NPG film as solid contact is reusable. This work provides a versatile method for fabricating the robust, reliable, and low-maintenance miniaturized ISEs.

An effective solid contact for an all-solid-state polymeric membrane Cd 2+ -selective electrode: Three-dimensional porous graphene-mesoporous platinum nanoparticle composite

“…7, similar selectivity coefficients are obtained for the GC/PGR-MPN/Cd 2+ -ISE and GC/Cd 2+ -ISE, indicating that the selectivity of the proposed ASS-Cd 2+ -ISE is not affected by the solid contact, but is dependent on the sensing membrane itself. These phenomena agree well with those from the reported literatures [45,46].…”

Simultaneous Determination of Na+, K+, Ca2+, Mg2+ and Cl− in Unstimulated and Stimulated Human Saliva Using All Solid State Multisensor Platform

“…Currently solid contact ISEs are based on conducting polymers such as PEDOT: PSS and POT . Other constructions are based on molecular redox couples and other materials like gold , platinum and C60 …”

Pre-Polarized Hydrophobic Conducting Polymer Solid-Contact Ion-Selective Electrodes with Improved Potential Reproducibility

“…The mainstream of the SCISE research is based on electrically conducting polymers (ECPs) [34][35][36] , large surface area carbon materials 32,[37][38][39][40] and their (nano)composites [41][42][43] , but also many other important types of SC materials have been reported such as redox polymers 44 , electronion exchange resins 45 , redox-active self-assembled monolayers 32 , tetrakis(4-chlorophenyl)borate anion doped nanocluster films 46 , nanoporous Au films 47 , and threedimensional molybdenum sulfide nanoflowers. 48 SCISEs with adequate potential stability were reported for both the ECP and carbon materials, but the use of large surface area inert carbon materials apparently results in better potential stabilities and less susceptibility to environmental conditions.…”