Highly stable ammonium ion-selective electrodes based on one-pot synthesized gold nanoparticle-reduced graphene oxide as ion-to-electron transducers

• Published in: Microchemical journal Vol. 190; p. 108717
• Main Authors: Duy Nguyen, Linh, Mau Dang, Chien, Chanh Duc Doan, Tin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2023
• Subjects: Ammonium; Gold nanoparticle; Ion-selective electrode; rGO; Solid contact; Ammonium; rGO; Ion-selective electrode; Gold nanoparticle; Solid contact
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2023.108717

[Display omitted] •Effective transducer for all-solid-state ion-selective electrodes based on gold nanoparticle-reduced graphene oxide.•AuNP-rGO composite was synthesized via a simple, eco-friendly, and one-pot method.•AuNP-rGO layer possesses a large surface area, high capacitance, and good hydrophobicity.•The electrode exhibited a rapid potential response to NH4+ ions without water layer formation.•The electrode offered good reproducibility, long operating life, and insensitivity to interferences. An effective transducer for all-solid-state ion-selective electrodes (SC-ISEs) was developed based on gold nanoparticle-reduced graphene oxide (AuNP-rGO) hybrid material. The AuNP-rGO composite was synthesized via a simple, eco-friendly, and one-pot method with sodium citrate as the reducing agent and the stabilizer. The nanocomposite was deposited on the GC substrate via the drop-casting method and then covered with an ammonium ion-selective membrane (NH4+-ISM) to form the potentiometric electrode. The AuNP-rGO layer possessed a large surface area, high capacitance, and good hydrophobicity; thereby effectively enhancing the potential stability of the electrode without the formation of an aqueous layer. The electrode also exhibited a rapid potential response (<10 s) to NH4+ ions, an excellent Nernstian response with a slope of 56.94 (±1.57) mV/decade, a detection range of 10-5 − 10-2 M, and a detection limit of 3.80 × 10-6 M. The proposed electrode also exhibited outstanding properties including insensitivity to interferences (light, oxygen, carbon dioxide, and redox species), good reproducibility, and long operating life. The electrode has been successfully applied for NH4+ detection in real water samples, which makes it a promising alternative for developing effective and robust SC-ISEs.