Design of all-solid-state chloride and nitrate ion-selective electrodes using anion insertion materials of electrodeposited poly(allylamine)-MnO2 composite

• Published in: Electrochimica acta 2021-09, Vol.389, p.138749, Article 138749
• Main Authors: Tsuchiya, Kazuhiko, Akatsuka, Tatsuya, Abe, Yoshinari, Komaba, Shinichi
• Format: Article
• Language: English
• Subjects: Anions; Cationic polymerization; Chloride ion; Electrodes; Insertion; Ion-selective electrode; Manganese dioxide; Membranes; Nitrate ion; Poly(allylamine); Polyvinyl chloride; Solid state; Substrates
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2021.138749

All-solid-state ion-selective electrodes as potentiometric ion sensors for the determination of chloride (Cl−) or nitrate (NO3−) ions were designed by inserting an electrodeposited composite layer consisting of manganese dioxide and poly(allylamine), a polymeric cation, as the inner solid-contact layer between the electrode substrate and poly(vinyl chloride) (PVC)-based ion-sensitive membrane containing the corresponding ionophores for Cl− or NO3− ions. The double-layered ion-selective electrodes exhibited selective and quick (≤10 s) potential response for the anions; moreover, the Nernstian slopes of the calibration curves of the electrodes were adequate, and the electrodes presented a wide detection range (10−5–10−1 mol dm−3). As the poly(allylamine)-manganese dioxide composites presented anion-insertion redox activity, the insertion of composite layers was highly effective in stabilizing the membrane potential of PVC because it lowered the impedance at the electrode interface, resulting in quicker responses to the anion activity in analytes than those of the corresponding electrodes without composite layers.