In this study,water soluble copper doped carbon nanodots(Cu-CDs) with high fluorescence quantum yield were prepared by one step hydrothermal method using citric acid and ethylenediamine as precursors and copper sulfate as metal dopants.A new method for the fluorescence determination of anthrax biomarker based on copper doped carbon nanodots was established based on the strong chelation of 2,6 pyridinedicarboxylic acid(DPA) with carbon nanodots.Under the optimum experimental conditions,there were good linear relationships for the fluorescence quenching rate of Cu-CDs with DPA in the concentration ranges of 5-100 nmol/L(r2=0994 1) and 150-400 nmol/L(r2=0997 6),and the detection limit of the proposed method was 23 nmol/L.With the advantages of low cost,high specificity,high sensitivity and simple operation,the method has a good application prospect in detection of anthrax biomarker.