Beyond Single-Analyte Detection: MXene Quantum Dot Platforms for Integrated Fluorescent Mapping of Fruit Bioactives...

MXene quantum dots (MQDs) have emerged as versatile zero-dimensional nanomaterials with tunable photoluminescence, abundant surface functional groups, and excellent charge-transfer capabilities, making them uniquely suited for sensitive and selective fluorescence-based sensing of bioactive compounds and quality indicators in fruits. This review examines synthetic strategies, including top-down and bottom-up approaches, functionalization methods, and reproducibility challenges, highlighting how interface engineering governs analytical performance. As the first comprehensive review in this field, it integrates insights on signal generation paradigms such as ratiometric, sequential, and "on-off-on" fluorescence mechanisms, emphasizing molecular recognition, selectivity control, and interference management. Key applications are surveyed, encompassing detection of antioxidants, metal ions, biogenic amines, and nitrites, with emphasis on real-sample performance, dual-modal strategies, and smartphone-compatible visual sensing. Finally, current limitations, standardization needs, and pathways toward field-deployable fruit monitoring are discussed, offering forward-looking perspectives for MQD-based fluorescent platforms in quality assessment and food safety.