In-situ grown core-shell CdMoO4@ZnS structures form S-scheme heterojunction for detecting tert-butylhydroquinone in food

Tert-butylhydroquinone (TBHQ), a widely used antioxidant for extending food shelf life, requires strict content control to ensure food safety. Here, we constructed a core-shell CdMoO 4 @ZnS S-scheme heterojunction via in situ growth for highly sensitive detection of TBHQ. Compared with our previously reported heterojunction sensors, this system achieves synergistic enhancement through polyvinylpyrrolidone-mediated morphology regulation and optimal shell-thickness engineering, effectively mitigating limitations in charge separation and stability. The developed photoelectrochemical sensor exhibits a wide dual-range detection capability (0.015–20 μM and 20–190 μM) with an ultralow detection limit of 1.8 nM. The exceptional sensing performance was elucidated by density functional theory calculations and redox potential analysis. Furthermore, the sensor achieves excellent recovery rates (97.05% - 104.23%) in real-sample analyses and retains more than 91.33% of its initial response after 8 weeks of storage, highlighting its strong potential for practical food-safety monitoring applications.