Fluorescent nanozyme based dual-channel lipopolysaccharide sensing

The release of lipopolysaccharide (LPS) during the proliferation and death of bacterial growth could cause acute versatile disorders like anaphylaxis and multiple organ failure. Analysis methods with high sensitivity and selectivity are expected to be developed to replace the limulus lysate test. Classical colorimetric method was equipped with portable visualization but limited with low sensitivity, while incredibly sensitive fluorescence sensing strategy suffered from negligible selectivity. Delicate design of the dual channels analysis would make the ends of such dilemma based on a fluorescent nanozyme of iron doped carbon quantum dots (Fe-CQDs) with both excellent fluorescence and peroxidase-mimic catalytic activity. Accordingly, a complementary dual channel analytical platform of LPS was prepared. The excellent peroxidase-like activity imparted the dominant selectivity for LPS (available under 6 interferences), while the powerful fluorescence property endowed the excellent sensitivity with the limit of detection (LOD) of an unprecedented level (0.0023 EU/mL). Our study has broadened a new path for design of efficient analytical methods via complement way.