Introducing New Conjugated Quantum Dots for Photothermal Therapy in Biological Applications

It is well-known that near-infrared (NIR) light sources are appropriate to ablate benign tumor irreversibly using heat treatment even in deep tissues. The laser light penetration into the skin in these wavelengths is deep (3–5 mm). Applying new stable materials for emitting NIR wavelengths in tumor positions can help cancer treatment. In this paper, synthesis of the conjugated core-multishell Ag/SiO2/Ag and Au/SiO2/Au quantum dots (QDs) with indocyanine green (ICG) is done and their theoretical and experimental absorptions and emissions in the NIR region are investigated. Thus, heat generation (high-resolution medical imaging capabilities) and emission enhancement are explained and described based on the FRET model for the proposed core-multishell QDs and it is shown that Ag/SiO2/Ag with ICG presents 4 times higher emission rate versus ICG alone in NIR region. Also, because of the plasmon hybridization and also resonance light penetration enhancement, the temperature in tissues increases that is useful for photothermal therapy and NIR high-resolution medical imaging for deep tissues. As an alternative application, these nanoparticles with amazing features are used as a heat source in cancer treatment for shallow and deep tissues. Finally, it is shown that Ag/SiO2/Ag QDs are the best solution for this purpose.