Photodynamic Therapy (PDT) is an effective cancer treatment method based on light-activation of a photosensitizer in the presence of cellular oxygen. In an effort to develop a novel PDT agent for breast cancer treatment we report on the synthesis and characterization of a bifunctional theranostic nanoprobe; possessing both a photosensitizer agent (Chlorin e6) and tumor targeting agent – an Epidermal Growth Factor (EGF) complex which targets the EGF receptor. It’s effectiveness in arresting cancer cell growth was tested using the breast cancer cell line MDA-MB-468. FT-IR analysis confirms that carbodiimide chemistry was effective in creating covalent bonded complexes between the photosensitizer Chlorin e6 (Ce6) and cysteamine, and the EGF and α-lipoic acid, which exhibit excellent affinity for gold nanoparticles (AuNPs). In particular, for the Ce6-cysteamine complex FT-IR analysis shows peaks with significant increase in intensity at 1713, 1542, 2227 cm⁻¹ and a decrease at 941 cm⁻¹ and for the EGF-α-lipoic acid complex there are significant decreases in intensity at 1708, 1073, 947 cm⁻¹ and increases at 1542, 1680, 1108 cm⁻¹. These changes are consistent with the creation of amide bonds, loss of carboxylic acid, and modification of the Nsingle bondH and Cdouble bondO bonds. Conjugation of these complexes to AuNPs was confirmed by UV–vis and Dynamic Light Scattering experiments. MDA-MB-468 cells treated with the bifunctional nanoprobe exhibited similar cell death and mitochondrial activity at 10-fold smaller Ce6 concentrations when bound to AuNPs compared with free Ce6. In addition only half the exposure time was needed to achieve these effects compared with unbound Ce6.