Developing a simple and cost-effective strategy to diagnose and treat cancer with a single and minimum dose through noninvasive strategies is highly challenging. Nano-sized graphene and graphene oxide (GO) are promising for biomedical applications, such as drug delivery and the photo thermal therapy of cancer. An acute promyelocytic leukemia line, such as NB4 cells, was detected by modified GO in extracellular and intracellular experiments. Results shows that GO can quench the fluorescence of the ssDNA fluorescent probe and its fluorescence is restored after a PML/ RAR fusion gene of NB4 cell lines is added. Therefore, the fusion gene can be detected accurately with this phenomenon. The best detection conditions for the fusion gene are found with assDNA fluorescent probe concentration of 200 nmol/ L in the presence of 0. 04 mg/ L GO at room temperature for 1 h.