Mercury is a dangerous neurotoxin that can cause a plethora of health effects at levels as low as 6 ppb in drinking water. Effects are often heightened in Artisanal Small-Scale Gold Mining communities as this economic activity takes place only in low-income regions where governments have insufficient regulatory frameworks and/or lack the capacity to control informal extractive industries, which makes the goal of phasing-out usage of mercury extremely challenging. Although necessary for validation, standard laboratory techniques to test water are accurate but are excessively expensive and impractical due to the advanced instrumentation, complex training, and analysis time. Here, we demonstrate the development of low-cost, facile, and rapid electrochemical nanosensors for mercury determination coupled with models on a mobile device to equip the communities with field measurements and management decisions. Electrodes were fabricated by laser scribing polyimide and decorated with nanocuprous oxide, recovered from recycled material, by anchoring copper nanoparticles using a novel magneto-hydrodynamic deposition process for creating carbon-metal nanohybrid structures. The electrochemical behavior and sensor performance were analyzed via cyclic voltammetry and stripping voltammetry. Mercury sensors were linear with a limit of quantitation of 25 ppb, response time of 3 min, and sensitivity of 300 pA-ppb-1. The sensors were paired with a hazard quotient assessment on smart technology to create a participatory monitoring effort in the region and map out areas of higher and lower risk. This information is used to create a Multi-Criteria Decision Analysis with the communities in order to implement a mitigation plan. The methods for developing the carbon nanosensors and decision support tools do not require specialty equipment, are facile, economic, and quick, which makes this method practical for development in rural areas. Sensors, risk models, and decision support present a new paradigm in participatory monitoring for vulnerable rural communities in Cauca, Colombia.

Nanosensors and decision support models paired on a mobile device for establishing a participatory monitoring program on mercury exposure in rural Colombia

2019 Fall National Meeting

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