Origami-based multifunctional sensing platform for sustainable detection of hazardous magnetic materials

Anthropogenic magnetite (AM) nanoparticles have been identified in the human brain and circulatory system, potentially linked to neurodegenerative and cardiovascular diseases. Specifically, AM and other magnetic nanocontaminants from industrial emissions and brake wear are hazardous components of particulate matter. Such contamination enriches urban soils with magnetite and other magnetic nanocontaminants, which can be absorbed by plants like rice and consequently enter the human body indirectly. Developing accurate and robust AM-sensing platforms is crucial, especially in areas where magnetic contamination threatens ecosystems and human health. Innovative materials, such as magnetoactive smart materials, are essential for creating sensors with specific, wireless, and adjustable magnetic properties for efficient detection and monitoring of soil contamination. This study presents an origami-based multifunctional sensing platform for sustainable detection of magnetic environmental contamination. Utilizing paper as its substrate for low-cost AM sensing, the device incorporates two wax/NdFeB magnets, four hydrophilic channels, and a hydrophilic analysis area, enclosed by hydrophobic wax. Through comprehensive analysis techniques including energy-dispersive X-ray spectroscopy, vibrating sample magnetometry, infrared spectroscopy, and photographic color changes, the device exhibited a detection limit below 156 mu g. The platform's versatility, affordability, sustainability, and capacity for multi- analysis indicate promising prospects for developing economically equitable, user-friendly, mechanically robust, and flexible magnetic contamination sensing devices. These devices eliminate the need for complex machinery while delivering rapid, accurate, and precise results tailored to diverse environmental needs, thus promoting sustainable and safe societies.