A Point-of-Care Aptasensor for the Real-Time Detection of Sepsis Biomarker

The rising demand for noninvasive portable point-of-care (POC) sensors for on-site detection of biomarkers reflects a shift toward personalized healthcare and real-time diagnostics. Lipopolysaccharide (LPS) is a key sepsis biomarker, a bacteria-borne endotoxin that can induce fatal conditions, such as septic shock, if left undetected. Timely bedside detection of LPS is critical for the appropriate intervention and treatment of sepsis. In this work, we report a highly sensitive electrochemical sensor chip designed for the selective detection of LPS, which is compatible with a portable analyzer for on-site detection. The sensor is fabricated using functionalized CNT (fCNT) and copper(I) oxide nanoparticles (Cu₂O). Functionalized with the LPS-specific aptamer, the sensor demonstrated remarkable selectivity and sensitivity toward LPS. It achieved a limit of detection (LOD) of 10 ag mL^-1 and exhibited a linear detection range from 10 ag mL^-1 to 10 ng mL^-1. The device detected LPS across various samples, including food samples such as mayonnaise and fruit juices, as well as a clinical sample, whole blood. These results underscore its potential for practical application in food quality assurance and clinical diagnostics, offering real-time analysis capabilities.