Ali, Md. AzaharKachoueim, Matin Ataei2024-10-242024-10-242024https://hdl.handle.net/10919/121381On-site rapid multi-ion sensing accelerates early identification of environmental pollution, water quality, and disease biomarkers in both livestock and humans. This study introduces a pocket-sized 3D-printed sensor, manufactured using additive manufacturing, specifically designed for detecting iron (Fe²⁺), nitrate (NO₃⁻), calcium (Ca²⁺), and phosphate (HPO₄²⁻). A unique feature of this device is its utilization of a universal ion-to-electron transducing layer made from highly redox-active poly-octylthiophene (POT), enabling an all-solid-state electrode tailored to each ion of interest. Manufactured with an extrusion-based 3D printer, the device features a periodic pattern of lateral layers (width = 80 μm), including surface wrinkles. The superhydrophobic nature of the POT prevents the accumulation of nonspecific ions at the interface between the gold and POT layers, ensuring exceptional sensor selectivity. Lithography-free, 3D-printed sensors achieve sensitivity down to 1 ppm of target ions in under a minute due to their 3D-wrinkled surface geometry. Integrated seamlessly with a microfluidic system for sample temperature stabilization, the printed sensor resides within a robust, pocket-sized 3D-printed device. This innovation integrates with milking parlors for real-time calcium detection, addressing diagnostic challenges in on-site livestock health monitoring, and has the capability to monitor water quality, soil nutrients, and human diseases.application/pdfenAttribution 4.0 Internationaladditive manufacturingimplantableion-to-electron transducerlivestockmilking parlormulti-ion sensorpoly-octylthiophenesubclinical hypocalcemiaArticle - Refereedhttps://doi.org/10.1002/advs.2024083142024