Development of biocompatible and multifunctional nanoprobes for tumor targeting, imaging, and therapy still remains a great challenge. Herein, gold nanoparticles (AuNPs) were synthesized in the cavity of horse spleen apoferritin protein (HoSAF) and protein surface was labeled with 2-amino-2-deoxy-glucose (2DG) as a cell surface glucose transport protein specific targeting probe to study the feasibility of its usage as a computer tomography (CT) contrast agent with tumor targeting capability through in vitro experiments. 2DG conjugated and gold-loaded apoferritin (Au-HoSAF-2DG) nanoparticles (NPs) showed selective targeting for human breast adenocarcinoma (MCF-7) cells when compared to normal breast (MCF-10A) cells. This AuNP-based imaging agent was found to be non-cytotoxic in a given concentration range with an apoptotic effect upon longer exposure times towards MCF-7 cells, while MCF-10A cells were affected less. This selective cell death would also be useful for further cancer treatments with the ability of X-ray attenuation in in vitro X-ray and computed tomography (CT) imaging.