Photothermal Enhancement in Core-Shell Structured Plasmonic Nanoparticles

Plasmonic nanoparticles (NPs) with photothermal effects can be exploited as efficient heat sources in various applications. Here, the photothermal properties in core-shell structured plasmonic NPs, including metal/silica NP, silica/metal NP, and metal/silica/metal NP, are investigated. Compared with bare metal NPs, the core-shell plasmonic NPs not only exhibit extremely agile tunability in the surface plasmon resonances but also show considerably enhanced photothermal effects in terms of the maximum temperature rise. For metal/silica NPs and metal/silica/metal NPs, the SiO2 shells function as effective thermal-protective layers for enhanced photothermal effect. For silica/metal NPs, the SiO2 core and the metal shell show uniform temperature rise. These findings are essential for applying the core-shell structured plasmonic NPs on photothermal imaging, nanofluidics, etc.