Potassium Ion Selective Electrode Using Polyaniline and Matrix-Supported Ion-Selective PVC Membrane

Abstract

Solid-state potassium ion selective electrode (K + ISE) has been the most studied chemical sensors due to its practical importance in biomedical applications. One of the major obstacles that prevented widespread use of solid-state K + ISE has been output potential drift problem. In this paper, we developed an electrochemical sensing unit in which working, counter, and reference electrodes are integrated in a single plane as all-solid-state form. In order to mitigate the output potential drift, a polyaniline intermediate layer and salt-saturated polyvinylebutyral top coating are introduced in the working and reference electrodes, respectively. Using cyclic voltammetry (CV), uniform layers of polyaniline are deposited on carbon electrode, as confirmed by scanning electron microscope observation. Potentiometry and electrochemical impedance spectroscopy measurement on our K + ISE show high sensitivity (60.5 mV/decade), low concentration for the limit of detection (10 −5.8 M), and large range of linear detection (10 −5 − 1 M), and superior selectivity of K + ISE against NH + 4 , Na + , Mg 2+ , Ca 2+ , and Fe 3+. With its high potential to be miniaturized, we foresee that our solid-state K + ISE will motivate the future applications in microdevices for clinical analysis, agricultural, and environmental applications.

3D Printed Ion-Selective Membranes and Their Translation into Point-of-Care Sensors

“…To further investigate the robustness of our approach to 3D print ISEs, we incorporate the well-known K + ionophore, valinomycin, into the 3D-printable resin to construct a K + -3D LC ISE. Figure C illustrates a linear calibration of a potassium LC ISE with a linear range from 1.0 M to 61 μM with a slope of 52.3 mV/Decade which is comparable to previously reported work using K + ISEs . Previous work by Bratov et al, using photocurable polymers, fabricated a K + ISE for incorporation into an ion-selective field-effect transistor (ISFET) using photolithography which resulted in a similar Nernstian slope of 57.4 mV/Decade at 25 ± 1 °C as well as a slightly larger linear detection range of 1 M to 10 μM .…”

“…Figure 4C illustrates a linear calibration of a potassium LC ISE with a linear range from 1.0 M to 61 μM with a slope of 52.3 mV/Decade which is comparable to previously reported work using K + ISEs. 55 Previous work by Bratov et al, using photocurable polymers, fabricated a K + ISE for incorporation into an ion-selective field-effect transistor (ISFET) using photolithography which resulted in a similar Nernstian slope of 57.4 mV/Decade at 25 ± 1 °C as well as a slightly larger linear detection range of 1 M to 10 μM. 56 Bilirubin, benzalkonium, and potassium sensors exhibited selectively over common interferences, and their selectivity coefficients are shown in SI Tables 5, 6, and 7, respectively.…”

Integration of an Aerosol-Assisted Deposition Technique for the Deposition of Functional Biomaterials Applied to the Fabrication of Miniaturised Ion Sensors

“…This roughness has an impact on the diffusion layer, which is translated into a difference in the time response and stability of the devices [ 34 , 37 ]. In addition, such roughness can increase the interfacial resistance of the films due to a change on their capacitive behavior [ 38 , 39 , 40 ]. Consequently, the fabrication of highly smooth and homogeneous films is necessary to achieve a systematic study of the effects of thickness in the performance of the ion sensors.…”

Towards Watt-scale hydroelectric energy harvesting by Ti3C2Tx-based transpiration-driven electrokinetic power generators

“…This behaviour is attributed to the specific cation-polyaniline interactions, such as the high permeability of K + in the polyaniline matrix. [54][55][56] Nevertheless, this result suggests that a multi-electrolyte solution, such as seawater, could further maximize the energy generation efficiency even for multi-component electrokinetic converting materials. Very importantly, the pseudo-streaming current produced by a NaCl solution in MPTEPG exceeds 7.8 mA, which is a 4-fold enhancement compared to that of MTEPG and 791-fold compared to that of cTEPG.…”