Abstract <p>Ensuring safety is the central objective in the assessment of food and environmental quality. With continuous advances in analytical technologies, nanomaterials (NMs) have driven a paradigm shift in safety testing owing to their tunable photoelectromagnetic effect, large specific surface area, targeted recognition ability, and biocompatibility. This review summarizes the categories, characteristics, and synthesis methods of zero-, one-, two-, and three-dimensional NMs. Particular emphasis is placed on the detection mechanisms and optimization strategies of NM-based sensors, including surface functionalization, heteroatom doping, and composite material design, in applications such as fluorescence quenching, surface enhanced Raman scattering (SERS), and antibacterial assays. The complementary role of Machine Learning (ML) in predicting NMs properties, optimizing structures, and guiding synthesis is also discussed. Despite their widespread application in food safety and environmental monitoring, challenges such as toxicity and stability remain. Future directions should focus on developing low toxicity, high-performance NMs and fostering interdisciplinary integration to enable more efficient, intelligent detection platforms, ultimately providing a closed-loop solution for food safety from laboratory research to industrial practice.</p> Graphic abstract <p></p>