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

The 3,3',5,5'-tetramethylbenzidine-HO (TMB-HO) platform has gained widespread use for rapid detection of various analytes in foods. However, the existing TMB-HO 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-HO 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-HO 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-HO platform was also used for rapid and accurate detection of ziram in real food samples like apple, tomato, and black tea.