This study presents a dual fluorescence probe strategy using glutathione-capped copper nanoclusters (GSH-CuNCs) and nitrogen-doped carbon dots (N-CDs) for the selective and sensitive detection of cisplatin (CIS) and etoposide (ETP) in rabbit plasma. The GSH-CuNCs exhibit a fluorescence signal increase at 615 nm with increasing CIS concentration, while the N-CDs show fluorescence enhancement at 480 nm in response to ETP. The probe demonstrates high sensitivity with detection limits of 6.95 ng mL⁻¹ for CIS and 7.63 ng mL⁻¹ for ETP, and excellent selectivity against potential interferences in rabbit plasma. The method was validated using real rabbit plasma samples and applied to estimate the pharmacokinetic parameters of CIS before and after ETP coadministration. The results indicate minimal pharmacokinetic interaction between CIS and ETP, suggesting that ETP does not significantly affect CIS pharmacokinetics. The dual nanoprobe strategy offers a rapid, selective, and cost-effective method for the quantification of CIS and ETP, making it promising for clinical applications requiring frequent drug monitoring. The study highlights the importance of monitoring combination chemotherapy regimens to ensure optimal efficacy and safety.This study presents a dual fluorescence probe strategy using glutathione-capped copper nanoclusters (GSH-CuNCs) and nitrogen-doped carbon dots (N-CDs) for the selective and sensitive detection of cisplatin (CIS) and etoposide (ETP) in rabbit plasma. The GSH-CuNCs exhibit a fluorescence signal increase at 615 nm with increasing CIS concentration, while the N-CDs show fluorescence enhancement at 480 nm in response to ETP. The probe demonstrates high sensitivity with detection limits of 6.95 ng mL⁻¹ for CIS and 7.63 ng mL⁻¹ for ETP, and excellent selectivity against potential interferences in rabbit plasma. The method was validated using real rabbit plasma samples and applied to estimate the pharmacokinetic parameters of CIS before and after ETP coadministration. The results indicate minimal pharmacokinetic interaction between CIS and ETP, suggesting that ETP does not significantly affect CIS pharmacokinetics. The dual nanoprobe strategy offers a rapid, selective, and cost-effective method for the quantification of CIS and ETP, making it promising for clinical applications requiring frequent drug monitoring. The study highlights the importance of monitoring combination chemotherapy regimens to ensure optimal efficacy and safety.