The synthesis and biological efficacy of novel nanomicelles that rapidly disassemble and release their encapsulated payload intracellularly under tumor-relevant glutathione (GSH) levels are reported. The unique design includes a PEG-sheddable shell and poly(ε-benzyloxycarbonyl-L-lysine) core with a redox-sensitive disulfide linkage.

Photoluminescence (PL) of Fe₃O₄ nanoparticle was observed from the visible to near-infrared (NIR) range by laser irradiation at 407 nm. PL spectra of ∼10 nm diameter Fe₃O₄ nanoparticles organized in different spatial configuration, showed characteristic emissions with a major peak near 560 nm, and two weak peaks near 690 nm and 840 nm. Different band gap energies were determined for these Fe₃O₄ nanoparticle samples corresponding to, respectively, the electron band structures of the octahedral site (2.2 eV) and the tetrahedral site (0.9 eV). Photothermal effect of Fe₃O₄ nanoparticles was found to be associated with the photoluminescence emissions in the NIR range. Also discussed is the mechanism responsible for the photothermal effect of Fe₃O₄ nanoparticles in medical therapy.