Triple negative breast cancer (TNBC) is the most fatal subtype among all other types of breast cancer and there are no targeted chemotherapy for the treatment of TNBC due to the absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2). To address this problem, we develop a targeted non-viral vector which could efficiently deliver the gene of interest and could also diagnose of TNBC. We have synthesized carbon quantum dots (CD) from sweet lemon peel, conjugated it with different generation of polyamidoamine (PAMAM) dendrimers to get CD-PAMAM conjugates (CDPs). RGDS peptide was further conjugated to CDP to target αvβ3 integrin which is over expressed in TNBC. DNA complexation assay, cellular cytotoxicity, hemolysis assay, DNase I assay, cellular uptake and in vitro transfection showed CDP3 as a promising gene carrier system TNBC gene therapy. Besides, CDP3 shows selective quenching of fluorescence in presences of Cu(II) with a quenching efficiency of about 93%. As the Cu(II) ion concentration remains upregulated in TNBC, CDP3 could be a promising theranostic tool for TNBC treatment. © 2019 Elsevier B.V.