Nanomembrane sensor-integrated central venous catheter for continuous monitoring of electrolytes in blood serum

Prolonged hospitalization often leads to repeated blood draws, particularly in critically ill patients, which causes up to 70% of them to develop hospital-acquired anemia. Sodium and potassium are regularly included in laboratory metabolic panels and are crucial electrolytes that influence clinical decisions, especially concerning essential cardiac and neurologic functions. For this reason, sodium and potassium ions are selected as target analytes for a thin-film sensor integrated with a central venous catheter (CVC). Here, we develop a sodium- and potassium-selective nanomembrane sensor system integrated with a CVC. This sensor suite features ionophore-based membranes deposited on graphene transducers through a customized airbrushing process, creating micro-thin coatings on conductive substrates. To enhance stability, we encapsulate the sensing units within elastomeric layers, assembled in a layer-by-layer manner. An experiment study verifies the long-term stability of the sensor using buffer and serum-diluted solutions at body temperature. The results of this study offer valuable insights for improving material robustness and reducing signal drift. Ultimately, this research aims to support continuous electrolyte monitoring, addressing the issue of hospital-acquired anemia in critically ill patients. • An ion-selective sensor integrated central venous catheter allows continuous electrolyte monitoring for hospital-acquired anemia patients without frequent blood drawings. • Fabricated sodium and potassium ion sensors are optimized for ideal thickness and sensitivity. • The long-term stability was shown with the human physiological condition using a buffer.