Simultaneous detection of C-reactive protein and lipopolysaccharide based on a dual-channel electrochemical biosensor for rapid Gram-typing of bacterial sepsis

Sepsis is a life-threatening multi-organ failure syndrome, with bacterial infections being the most common cause. Rapid Gram-typing is imperative to assist in antibiotic intervention. C-reactive protein (CRP) and lipopolysaccharide (LPS) are effective biomarkers for discerning the Gram type of bacteria but differ by several orders of magnitude in clinical detection, thereby impeding their simultaneous detection. And two independent methods are time-consuming and laborious. In this study, a dual-channel electrochemical biosensor was developed for simultaneous detection of LPS and CRP. Under optimal conditions, linear ranges of LPS (0.5-1000 pg/mL) and CRP (0.1-20 μg/mL) were obtained in line with the clinical evaluation scopes. In simulated sample tests, Gram-positive, Gram-negative, and healthy plasma samples were clearly distinguished by the developed biosensors, and these results were consistent with that of enzyme-linked immunosorbent assay (ELISA). In addition, the results of the plasma samples tested by the electrochemical biosensor matched those derived from blood cultures in the laboratory. Collectively, the electrochemical biosensor was expected to provide the scientific basis for the rapid Gram-typing and point-of-care detection of bacterial sepsis.