Additive Manufacturing Electrochemistry: Development of Bismuth Oxide Microparticle Filament for Lead (II) Detection

Abstract

Accurate, rapid, and cost-effective validation of water quality is essential to ensure that the World Health Organization's (WHO) standards are met and that the United Nations Sustainable Development Goal 6—Clean Water and Sanitation is achieved. To this end, the development of additive-manufactured electrodes using recycled polylactic acid, nanocarbon black, and micro-sized bismuth oxide is reported. These electrodes, that are fabricated using a thermal mixing approach, can be customized to incorporate varying amounts of bismuth oxide (1, 2.5, and 5 wt%) maintaining the integrity of the base polymer. The electrodes developed in this work demonstrate significant potential for the electrochemical detection of lead (II) within water, achieving limits of detection of 0.79, 0.93, and 4.29 μg L⁻¹ (3σ), for the 1, 2.5, and 5 wt% bismuth oxide sensors, respectively. These detection limits are notably below the WHO recommended threshold of 10 μg L⁻¹ for lead in domestic water and even achieve the 2036 European Union targets of 5 μg L⁻¹. The 2.5 wt% bismuth oxide electrodes exhibit excellent reproducibility and specificity, achieving average recovery rates of 98.28% and 100.15% in the analysis of spiked lead (II) samples in deionized and condensed atmospheric water, respectively. This approach is further validated against inductively coupled plasma mass spectroscopy measurements.