In Situ Photothermal Response of Single Gold Nanoparticles through Hyperspectral Imaging Anti-Stokes Thermometry

BARELLA, MARIANO; VIOLI, IANINA L.; GARGIULO, JULIAN; MARTINEZ, LUCIANA P.; GOSCHIN, FLORIAN; GUGLIELMOTTI, VICTORIA; PALLAROLA, DIEGO; SCHLÜCKER, SEBASTIAN; PILO-PAIS, MAURICIO; ACUNA, GUILLERMO P.; MAIER, STEFAN A.; CORTÉS, EMILIANO; STEFANI, FERNANDO D.

ACS NANO

AMER CHEMICAL SOC

Año: 2020

1936-0851

Several fields of applications requirea reliable characterization of the photothermal response and heat dissipationof nanoscopic systems, which remains a challenging task both for modeling and experimentalmeasurements. Here, we present an implementationof anti-Stokes thermometry that enables the insitu photothermal characterization of individual nanoparticles (NPs) from asingle hyperspectral photoluminescence confocal image. Themethod is label-free, potentially applicable to any NP with detectableanti-Stokes emission, and does not require any prior information about the NPitself or the surrounding media. With it, we first studied the photothermalresponse of spherical gold NPs of different sizes on glass substrates, immersedin water, and found that heat dissipation is mainly dominated by the water forNPs larger than 50 nm. Then, the role of the substrate was studied by comparingthe photothermal response of 80 nm gold NPs on glass with sapphire and graphene,two materials with high thermal conductivity. For a given irradiance level, theNPs reach temperatures 18% lower on sapphire and 24% higher on graphene than onbare glass. The fact that the presence of a highly conductive material such asgraphene leads to a poorer thermal dissipation demonstrates that interfacialthermal resistances play a very significant role in nanoscopic systems, andemphasize the need for in situ experimental thermometry techniques. Thedeveloped method will allow addressing several open questions about the role oftemperature in plasmon-assisted applications, especially ones where NPs ofarbitrary shapes are present in complex matrixes and environments.