Fabrication of inkjet-printed gold nanostar patterns with photothermal properties on paper substrate

Inkjet printing technology has brought signifcant advances in patterning various functional materials that can meet important challenges in personalized medical treatments. Indeed, patterning of photothermal active anisotropic gold nanoparticles is particularly promising for the development of low-cost tools for localized photothermal therapy. In the present work, stable inks containing PEGylated gold nanostars (GNSs) were prepared and inkjet printed on a pigment-coated paper substrate. A signficant photothermal effect (ΔT≅20°C) of the printed patterns was observed under near infrared (NIR) excitation of the localized surface plasmon resonance (LSPR) of the GNSwith low laser intensity (I≅0.2 W/cm²). Besides the pronounced photothermal effect, we also demonstrated, as an additional valuable effect, the release of a model fluorescent thiol-terminated Bodipy dye (BDP-SH) from the printed gold surface, both under bulk heating and NIR irradiation. These preliminary results suggest the way of the development of a new class of low-cost, disposable, and smart devices for localized thermal treatmentscombined with temperature-triggered drug release.