Theranostic agents were drawing a huge attention in the personalized medication. In this study, we established a facile technique, plant extract-based technique for the synthesis of reduced nano-graphene oxide (RNGO) with low cytotoxicity. We formed platforms of photothermal (PT) therapy and further explained that the synthesized RNGO can be utilized as ready to use PT therapy without any additional surface adjustment. In the meantime, with the help of a constant-wave NIR laser (near-infrared), in vitro esophageal adenocarcinoma cell line (OE-19) cancer cells were effectively ablated, because of the PT impact of RNGO. The outcomes propose that the RNGO was appropriate for PT therapy and photoacoustic imaging of the tumor, which is assuring for theranostic nanomedicine.