Iridium (IV) oxide-mediated microorganism nanozyme amplified immunochromatographic assay for dual-signal sensitive detection of salbutamol

Salbutamol (SAL) residues in edible animal tissues have various adverse effects on human health after digestion. Herein, we constructed an innovative functionalized microorganism nanozyme-mediated immunochromatographic assay for sensitive and accurate dual-colorimetric detection of SAL by introducing the Yeast@IrO2 as bifunctional signal tag. The Yeast@IrO2 was synthesized by self-assembling iridium (IV) oxide nanoparticles (IrO2 NPs) on the surface of inactivated yeast cells, which showed high monodispersity, uniform shapes, preeminent biocompatibility and rapid antibodies labeling capacity. After reaction for 15 min, through further employing [3,3 ',5,5' Tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2)] as substrate to trigger the color reaction, the developed biosensor performed with outstanding performance, including limit of detection (0.012 ng/mL), linearity (R2 > 0.99) and selectivity. Concurrently, the visual limit of detection (0.2 mu g/kg) and satisfactory recoveries (85.6%-103.9%) were obtained by monitoring SAL in pig liver and beef samples. Briefly, this work provided a universal platform for sensitive, precise and rapid detection of toxic and hazardous substances in food safety fields.