<p>Background: Advances of nanotechnology have led to the development of nano-materials with both potential diagnostic and therapeutic applications. Among them, Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) have received particular at-tention. Modified EDC coupling fraction was used to fabricate the SPION-C595 as an MR imaging contrast agent for breast cancer detection in early stages.<br /> Methods: Nanoprobe characterization was confirmed using Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM-EDAX), and Photon Correlation Spectroscopy (PCS). Protein and iron concentration of nanoprobe was examined by standard method. MTT assay was performed to evaluate the cytotoxicity of the nanoprobe in breast cancer cell line (MCF-7). T₂-weighted MR imaging was performed to evaluate the signal enhancement on T₂ relaxation time of nanoprobe using spin-echo pulse sequence.<br /> Results: As results showed, SPIONs-C595 provided active targeting of breast cancer cell (MCF-7) at a final concentration of 600 <em>&micro;gFe/ml</em>. The final concentration of protein was calculated to be at 0.78 <em>&micro;gprotein/ml</em>. The hydrodynamic size of the nano-probe was 87.4&plusmn;0.7 <em>nm</em>. The MR imaging results showed a good reduction of T₂ relaxation rates for the highest dose of SPIONs-C595.<br /> Discussion: Based on the results, SPIONs-C595 nanoprobe has a potential in T₂-weighted MR imaging contrast agent for breast cancer cell (MCF-7) detection.</p>