This paper aims to demonstrate the efficacy of the immobilisation of the chemotherapy drug doxorubicin on nanodiamond platforms as a potential cancer therapy. This effective drug is experimentally fed into a human breast adenocarcinoma cell lines. Drug loading activity and cell viability are detected by spectrometer, microscopy, and MTT assay in this study at Biomedical Physics Research Unit, Department of Physics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand between 1 Oct 2018 and 10 Jun 2019. Experimental results show that in the basic environment (pH = 8.0), the nanodiamond carboxylic group cooperated with the doxorubicin amino group to form a stable and non-covalent bond on nanodiamond surfaces served as a simple physical adsorption. In an acidic environment suitable to targeting the cancer cells, the nanodiamond carboxylic group ionised so that doxorubicin is effectively released. Doxorubicin therefore affirmatively absorbed into the cytoplasm and later into the nucleus. The significant finding of the study is that IC-50 equivalent to 0.40 mg/mL and viable nanodiamond-doxorubicin is a good candidate material for drug delivery.