Engineering gold nanoclusters anchored cobalt oxyhydroxide with bifunction for discriminative monitoring azodicarbonamide

Precise and convenient detection of azodicarbonamide (ADC) is indispensable for safeguarding food safety and public health. Herein, a new ratio fluorescence strategy was strategically designed for monitoring ADC with excellent sensitivity and strong resistance to interference based on gold nanoclusters anchored cobalt oxyhydroxide nanocomposite (AuNCs@CoOOH). The AuNCs@CoOOH integrated two functions of CoOOH (quencher and mimetic oxidase) and fluorescence property of AuNCs, which can catalyze oxidation of non-fluorescent thiamine to fluorescent thiochrome. Meanwhile, the fluorescence emitted by AuNCs was attenuated by CoOOH via a fluorescence resonance energy transfer, forming a ratio response. Owing to analyte-initiated reduction of CoOOH, the AuNCs@CoOOH recognized glutathione. Coupling with specific reactions of ADC and glutathione, a ratio-based fluorescent platform is devised for sensitive detection of ADC, achieving a detection limit of 0.034 μM. The method proved an effective way for accurately monitoring ADC in flour samples, thereby enhancing its practical utility in ensuring food safety.