Multifunctional nanoparticles offer promising personalized treatments for cancer disease detection, drug delivery, tissue repair, and photothermal therapy. Two types of gold-coated superparamagnetic iron ixide nanoparticles (Au-SPIONs) were synthesized: Au-Fe3O4 and Au-Fe2O3. The ultrasmall Au-Fe3O4 nanospheres with increasing diameters (10-30nm) demonstrated potential for selectively destroying tumors, safely delivering drugs, and imaging tissue. Novel nerve growth factor (NGF) conjugated Au-Fe2O3 nanoparticles were also utilized with a self-designed magnetic field to stimulate neuronal differentiation and growth for nerve regeneration in the brain. Ultimately, these magnetic and light-responsive NGF-Au-SPIONs are extremely efficient, combingin multiple purposes into a single, inexpensive platform for innovative biomedicine.