Wide-range and sensitive detection of LPS using a transporter@liposome enhanced electrochemical aptasensor

Stringent detection of lipopolysaccharide (LPS) is crucial for ensuring drug and food safety, enabling effective control of endotoxin contamination in pharmaceuticals and food. Given the wide variation in LPS concentrations across different matrices, the assay methods for LPS are extremely needed combining a wide dynamic range with high sensitivity. Employing metallohelicate embedded liposomal for electrochemical sensor modification, a novel strategy is developed for high-performance detection of LPS with aptamer probes. Metallohelicates are non-destructively incorporated into the lipid bilayer and act as a selective chloride ion transporter, enhancing the influx of chloride ions across the membrane, thereby increasing the permeability of the liposomal membrane and its conductivity. The current response is therefore amplified, significantly improving the sensitivity and reducing the limit of detection (LOD). The extensive surface area of liposomal spherical structure with high-density aptamers also greatly enhances its capacity to adsorb high-concentration targets. This aptasensor achieves a LOD of 0.44 fg/mL and provides an extremely wide dynamic range up to 1 μg/mL, with satisfied recovery and accuracy for LPS detection in pharmaceutical injections and food matrices.