Potassium ions (K + ) are essential electrolytes in the human body, crucial for maintaining cell membrane potential, neuromuscular excitability, and cardiac function, with blood potassium (BP) levels needing to stay within 3.5–5.5 mmol/L to prevent serious health issues. Current BP detection methods rely on lab testing, which is costly, slow, and unsuitable for remote areas. This study developed a handheld micro-volume BP detection device using paper-based ion-selective electrodes (ISEs). The device, built on a PET substrate with screen printing and a custom ion-sensitive membrane, features a miniaturized sensor that requires only 2 µL of fingerstick blood for rapid BP measurement, reducing costs significantly. A handheld reader with built-in electrochemical signal processing and wireless transmission allows instant results display and data upload to smartphones. The device demonstrated excellent linearity, repeatability, and stability, indicating its potential for acute care, chronic disease management, and sports medicine.
Human sweat has the potential to be sufficiently utilized for noninvasive monitoring. Given the complexity of sweat secretion, the sensitivity and selectivity of sweat monitoring should be further improved. Here, we developed an olfactory-inspired separation-sensing nanochannel-based electronic for sensitive and selective sweat monitoring, which was simultaneously endowed with interferent separation and target detection performances. The special separation-sensing strategy imparts functional composite membranes with a high sensitivity of 113 mV dec–1 for potassium detection. The excellent mechanical properties and conformability of the Kevlar aramid nanofiber layer bring well-wearing performances to realize continuous wireless sweat monitoring. The recognition between functional molecules and target ions is proved at the molecular level in detail in the article. The replacement of functional molecules proves the universality of the strategy for performance enhancement in intricate biofluid analysis systems.
危险品化学品经营许可证（带存储）