Fluoroquinolones (FQs) are widely used in the poultry and livestock industries due to their effectiveness in preventing and treating bacterial infections. However, improper use and poor biodegradability lead to their accumulation in the food chain, posing risks to human health. To address this, a novel ratiometric fluorescence probe was developed for sensitive FQ detection. The probe consists of dithioerythritol-protected silver–gold nanoclusters (DIT@AgAuNCs) with weak red fluorescence at 615 nm. Addition of Al3+ induces nanocluster aggregation, enhancing fluorescence emission. Upon adding FQs to the DIT@AgAuNCs/Al3+ system, fluorescence at 615 nm decreases due to the removal of Al3+ from the ligand (DIT) surface via coordination interactions. Simultaneously, a new blue fluorescence peak emerges at 465 nm, attributed to the formation of an Al3+-FQs coordination complex. Under optimal conditions …