Unveiling the potential of luminescent metal–organic frameworks as optical sensors for the detection of food contaminants

Food toxicity has become an increasing concern due to the rising levels of contaminants in food products. The identification of foodborne toxins is crucial for safeguarding public health and ensuring food safety. In recent decades, advances in sensor technology have enabled the rapid, efficient, and reliable detection of food pollutants. Metal–organic frameworks (MOFs) have garnered significant attention as efficient sensory materials due to their active metal sites, large surface areas, excellent chemical and thermal stability, and tunable structures with variable pore sizes, making them a promising alternative to conventional analytical techniques. However, despite extensive research on MOFs for contaminant detection, there is a notable lack of studies dedicated specifically to luminescent MOF-based optical sensors for food contaminants. This review comprehensively discusses the latest advancements in the design and development of luminescent MOFs based optical sensors, focusing on their synthesis routes—including solvothermal, mechanochemical, sonochemical, and electrochemical methods—and the strategies employed to induce and tune their luminescence, such as ligand-based, metal-based, guest-induced, and exciplex emission. Special attention is given to their working mechanisms and their applications for the detection of wide spectrum of food contaminants, including veterinary drug residues, heavy metals, pesticides, microbial pathogens, illegal additives, and other hazardous substances. Challenges such as stability, scalability, and regulatory concerns are critically analyzed, along with future perspectives that emphasize integration with the real-time monitoring platforms. This work aims to serve as a foundational resource for researchers and stakeholders developing next-generation sensors for enhanced food safety and public health protection.