Interfacial Transformation of an Amorphous Carbon Nanofilm upon Fe@Ag@Si Nanoparticle Landing and its Colloidal Nanoscrolls: Enhanced Nanocompositing-Based Performance for Bioapplications.

We report a novel method for generating magneto-plasmonic carbon nanofilms and nanoscrolls using a combination of two gas-phase synthetic techniques. Ternary Fe@Ag@Si "onion-like" nanoparticles (NPs) are produced by a magnetron sputtering inert gas condensation source and are in situ landed onto the surface of carbon nanofilms, which were previously deposited by a DC arc discharge technique. Subsequently, a polyethylenimine-mediated chemical exfoliation process is performed to obtain carbon nanoscrolls (CNS) with embedded NPs (CNS-NPs). Of note, the carbon nanofilms undergo an interfacial transition upon addition of NPs and become rich in the sp2 phase. This transformation endows and enhances multiple functions, such as thermal conductivity and the plasmonic properties of the nanocomposites. The obtained two-dimentional (2D) nanocomposites not only exhibit a highly efficient surface-enhanced Raman scattering property, allowing sensitive detection of malachite green isothiocyanate (MGIT) and adenosine-triphosphate (ATP) molecules at concentrations as low as 1 × 10-10 M, but also show enhanced near-infrared-responsive photothermal activity when forming stable colloidal 1D CNS-NPs. In addition, the CNS-NPs present an enhanced single- and two-photon fluorescence in comparison with pristine CNS and NPs. These results make them suitable for the rational fabrication of "all-in-one" multifunctional nanocomposites with tubular structures toward a wide range of biomedical solutions.