Construction of a novel Au@Os mediated TMB-H2O2 platform with dual-signal output for rapid and accurate detection of ziram in food

The 3,3′,5,5′-tetramethylbenzidine-H2O2 (TMB-H2O2) platform has gained widespread use for rapid detection of various analytes in foods. However, the existing TMB-H2O2 platforms suffer from limited accuracy, as their signal output is confined to the visible region, which is prone to interference from various food colorants in real samples. To address this challenge, a novel Au@Os-mediated TMB-H2O2 platform is developed for both rapid and accurate detection of analytes in foods. The prepared Au@Os NPs exhibit remarkable peroxidase-like activity, making the platform display dual absorption peaks in visible and near-infrared (NIR) regions, respectively. This Au@Os-mediated TMB-H2O2 platform exhibited three linear ranges across different concentrations of ziram from 1–100, 150–600, and 800–2000 nM with limit of detection (LOD) 7.9 nM and limit of quantification (LOQ) 24.15 nM respectively. Further, the Au@Os-mediated TMB-H2O2 platform was also used for rapid and accurate detection of ziram in real food samples like apple, tomato, and black tea. •Synthesis of a novel Au@Os core-shell NPs with excellent peroxidase-like activity.•Au@Os mediated TMB-H2O2 sensing platform with Vis and NIR absorption signal-output.•Rapid and accurate detection of ziram in real foods.•Improved sensitivity for ziram detection with LOD of 7.9 nM and LOQ of 24.15 nM.