Fluorescent metal nanoclusters for food safety: Advances, challenges, and future perspectives in contaminant detection.

Metal nanoclusters (MNCs) have emerged as promising nanoprobes due to their ultra-small size, excellent photostability, low toxicity, high biocompatibility, tunable emission, and large Stokes shift. These properties make MNCs highly suitable for sensing, bioimaging, and photocatalysis. In food science, fluorescence (FL)-based MNC sensors remain underexplored despite their proven potential in environmental monitoring. This review highlights advances in MNC-based FL sensing for detecting contaminants such as heavy metals, pesticides, antibiotics, dyes, and food toxins in diverse matrices. It discusses synthesis, functionalization, and doping strategies that enhance MNC stability, selectivity, and sensitivity. Current challenges, including reproducibility, size control, quantum yield, and large-scale applicability, are critically evaluated. By addressing these limitations, MNCs hold immense promise for real-time, sustainable contaminant detection in food and water, paving the way for innovative food safety monitoring platforms.