In this study, molecularly imprinted Mn-doped ZnS quantum dots were used as nanosensors to determine diazepam and its metabolites. Mn-doped ZnS quantum dots (QDs) capped with L-cysteine were prepared using a sodium thiosulfate precursor and characterized by various methods. Methacrylic acid was used as a precursor for the synthesis of MIP Mn-doped ZnS QDs and then used to measure diazepamin various samples. The linear dynamic range, coefficient of determination, and detection limit were found to be 0.3 - 250 mol/L 0.989 and 8.78 10-2 mol/L, respectively. The interference studies showed that the prepared nanosensor was selective for diazepam and its metabolites