The desalted DNA was exposure to 365 nm LED light for 5 minutes at room temperature in water. Then, DNA was subjected to HPLC for further purification. ODN6UV was dissolved in buffer A and then incubated with cathepsin B and acid phosphatase for enzymatic cleavage study. ODN6UV (2 M) was incubated with 0.2 U/mL cathepsin B in buffer A at 37 °C for 1 hour. Then, 0.2 U/mL acid phosphatase was added, and the mixture was incubated at 37 °C for 1 hour. Then, the mixture was subjected to fluorescence spectra detection (PerkinElmer LS-50B Luminescence Spectrophotometer). Excitation wavelength: 360 nm, slit width: 7 nm; emission wavelength: 380 to 650 nm, slit width: 7 nm.