3D-printed extraction chamber and paper-based screen-printed sensors for zinc analysis in soil and Antarctic sediments.

Studying chemical substances in Antarctic soils, such as zinc ions, provides crucial insight into ecosystem changes. Conventional analyses typically require laboratory-based instrumentation (e.g., atomic absorption spectroscopy), with high energy consumption and use of high volumes of solvents, making them unsuitable for remote environments. Herein, we developed an analytical approach that combines Zn extraction from soil with its analysis utilizing a simplified and green analytical methodology. We customized a 3D-printed chamber to extract water-soluble and exchangeable Zn fraction, which is the most relevant for bioavailability in ecosystem exchanges. The analysis of extracted Zn is carried out by square wave anodic stripping voltammetry with a miniaturized paper-based screen-printed sensor, based on ex-situ bismuth modification. Our results showed a linear range of 0.05-1.25 ppm, a limit of detection of 0.015 ppm, and good agreement with a reference analytical method. Our approach provides green innovation for a methodology applicable in remote areas, such as Antarctica, as proven by our analysis using RGBfast metrics, which is essential for observing soil ecosystem responses to global warming.