This paper presents a novel smartphone-based analyte sensing platform utilizing the built-in magnetometer for signal transduction via analyte-responsive magnetic-hydrogel composites. The hydrogels dilate in response to targeted stimuli, displacing attached magnetic material, and a bilayer hydrogel amplifies this motion for sensitive, optics-free, quantitative liquid-based measurements. The concept is demonstrated with glucose-specific and pH-responsive hydrogels, achieving glucose detection down to single-digit micromolar concentrations. The platform's adaptability suggests potential for diverse analyte sensing applications.

Mark Ferris, Gary Zabow