A platinized Pt wire as an affordable platform for the voltammetric determination of ammonia

Abstract Ammonia is a major contributor to eutrophication, making its reliable monitoring essential for protecting aquatic ecosystems and safeguarding water quality. Here, we report a miniaturized electrochemical platform based on a platinized Pt wire for the voltammetric determination of ammonia in natural and drinking water samples. The electrodes were fabricated from Pt wires (⌀ = 0.5 mm) modified with electrodeposited Pt microparticles, yielding a highly active electrochemical surface with enhanced voltammetric response toward ammonia electrooxidation in alkaline medium. Differential pulse voltammetry enabled ammonia determination over a linear range from 0.5 to 50 µmol L − 1 (0.007 to 0.7 ppm N), with limits of detection and quantification of 0.1 µmol L − 1 and 0.33 µmol L − 1 , respectively. The proposed platform provides adequate detectability for monitoring ammonia concentrations within the limits established by Brazilian environmental regulations for drinking water. The applicability of the proposed platform was evaluated using four water samples. Recovery values ranging from 92 to 105% and satisfactory precision were achieved, both meeting AOAC International guideline criteria, confirming the suitability of the proposed method for accurate ammonia determination in water samples. The enhanced analytical performance achieved after Pt microparticle electrodeposition highlights the effectiveness of surface platinization for ammonia sensing. The proposed platform combines low reagent and sample consumption, reduced waste generation, minimal sample preparation, and satisfactory analytical performance, demonstrating its potential for routine ammonia monitoring in aquatic environments.