Combining superior surface enhanced Raman scattering and photothermal conversion on one platform: a strategy of ill-defined gold nanoparticles

Abstract

We report a facile one-pot strategy of “ill-defined gold nanoparticles (ID-GNPs)” to prepare dual functional gold nanoparticles. The ID-GNPs were prepared in a simple way by tuning the morphology of the regular GNPs with a tiny amount of cetyltrimethyl ammonium bromide (CTAB). The prepared ID-GNPs comprise both quasi-spherical and elongated gold nanoparticles, which allow the presence of coarse surfaces and high density of hot spots. The substrates fabricated with ID-GNPs show dramatic Raman enhancement for p-aminothiophenol (PATP). PATP can be detected even at a concentration of 10⁻¹² mol L⁻¹. Meanwhile, these ID-GNPs can efficiently convert absorbed photons into heat when irradiated with 808 nm laser. The temperature of the ID-GNPs dispersion can be enhanced 26.0 °C within 10 minutes, which is capable of inducing the phase transition of a temperature-sensitive supramolecular system. Our study suggests that with the strategy of ‘ill-defined gold nanoparticles’, these two different functionalities can be achieved on one platform.