Comprehensive advances in CsPbBr ₃ perovskite quantum dots for ultrasensitive fluorescent nanosensors in food safety monitoring

Ensuring food safety requires rapid, sensitive detection of pathogens and contaminants, driven by global challenges such as rising foodborne illnesses and regulatory demands for real-time monitoring. This review examines cesium lead bromide (CsPbBr₃) perovskite quantum dots (PQDs) as advanced fluorescent nanosensors for multiplexed detection of foodborne pathogens (<i>e.g.</i>, <i>Salmonella</i>, <i>Vibrio</i>) and non-pesticide contaminants (<i>e.g.</i>, mycotoxins, heavy metals, dyes, antibiotics) in complex food matrices. Utilizing high quantum yields and narrow emission spectra, these nanosensors achieve detection limits as low as 10 colony-forming units per milliliter (CFU mL^-1) and sub-nanomolar levels <i>via</i> fluorescence resonance energy transfer (FRET), photoinduced electron transfer (PET), and aggregation-induced quenching (AIQ) mechanisms. We explore advanced synthesis methods (hot-injection, ligand-assisted reprecipitation (LARP), microfluidics) and surface modifications (molecularly imprinted polymers (MIP), metal-organic frameworks (MOF), silica coatings) to enhance stability and specificity. This focused and up-to-date comprehensive review is dedicated to the use of CsPbBr₃ PQDs in the fluorescence-based detection of foodborne pathogens and non-pesticide contaminants. Unlike prior reviews on general perovskite QDs or broader nanosensors, it provides a structured framework emphasizing synthesis strategies, detection mechanisms in real food matrices, comparative performance with other nanomaterials, toxicity mitigation, and prospects for IoT-integrated, regulatory-compliant, field-deployable sensing technologies. The review addresses toxicity and instability challenges through lead-free alternatives and Internet of Things (IoT)-integrated platforms, paving the way for scalable, real-time food safety diagnostics.