Biomimetic cell model for fluorometric and smartphone colorimetric dual-signal readout detection of bacterial toxin

Pathogenic bacterial infection has emerged as a global health threat, causing death, disability, and socioeconomic disruption worldwide. The current detection system is generally based on the various characteristics of pathogenic bacteria themselves. The readout method, which relies on the characteristic change of pathogenic bacteria receptor (normal cells), is rarely used. Herein, inspired by the pathogenesis and mimicking a minimalistic model system of living cells, a biomimetic liposome membrane comprising lecithin and cholesterol and encapsulated with rhodamine B (RhB) was innovatively developed to analyze the virulence factor with significantly simplified behavior. Based on the specific interaction between cholesterol and streptolysin O (SLO), the biomimetic liposome membrane was selectively ruptured, causing RhB emancipation and enabling fluorescent and intelligent colorimetric dual-signal detections of SLO toxin with limits of detection (LODs) as low as 0.05 μg·mL−1 and 0.33 μg·mL−1, respectively. We anticipate that this study will provide new insights into the development of host cells and biomimetic-system-based methods for pathogen detection.