Figure 4.

Inorganic LTNs. Schematic illustration of the most explored inorganic LTNs built from gold (Au), transition metal chalcogenides or selenides (TMC/TMS), carbon (C), or hybrids thereof. The structures presented in the light green circle are LTNs built from single materials, and are basic building blocks for more complicated LTNs (light blue circle). LTNs built from gold include nanosphere, nanorod, nanocage, nanoshell, and gold beltflower morphologies (from right to the left), which could be made into plasmonic vesicles, labeled with ⁶⁴Cu or IONPs for enhanced therapeutic and imaging capabilities. LTNs built from TMC/TMS could adopt sphere, sheet, or rod morphologies (from left to right), and could form core/shell structures with IONPs, be labeled with ⁶⁴Cu or ¹³¹I, or doped with IONPs. LTNs made from carbon include graphene, graphene quantum dots, carbon dots, and carbon nanotubes, which could be doped with quantum dots or IONPs, or coated with mesoporous silica for improved tumor imaging or delivery. In addition, hybrid LTNs were created to improve the imaging or therapeutic outcomes, which include Cu₉S₅ coated gold spheres, gold-coated carbon nanotubes, graphene-coated gold nanorods, gold nanoparticle-doped graphene, and graphene-loaded plasmonic vesicles.