abstract
Among the foreseeable therapeutic approaches at the cellular level, nanoplatform-driven photothermal therapy is a thriving tool for the selective eradication of malignant tissues with minimal side effects to healthy ones. Hence, chemically versatile, near-infrared absorbing plasmonic nanoparticles are distinctly appealing and most sought after as efficient photothermal agents. In this work, a straightforward method to synthesize monodisperse PEGylated copper sulfide nanoparticles of pure covellite (CuS) phase, featuring strong localized surface plasmonic resonance absorption in the near-infrared and flexible surface chemistry, imparted by monomethyl ether polyethylene glycol molecules, is developed and optimized. These nanoparticles show a remarkable photothermal heat conversion efficiency (HCE) of 71.4%, which is among the highest for CuS systems and rivals that of plasmonic noble metal nanostructures. Moreover, through critical evaluation and mathematical modeling of the material's properties and measurement methodology, it is assessed that the calculated HCE values drastically depend on experimental conditions such as wavelength-dependent solvent absorption properties, sol concentration, and optical path. These findings are of paramount relevance to the photothermal community, since they call for a standardization of the procedure for the evaluation of the HCE of proposed photothermal agents, in order to make the reported values universally and reliably comparable.
keywords
OPTICAL-PROPERTIES; GOLD NANOPARTICLES; PLASMON RESONANCE; NANOCRYSTALS; THERAPY; APOPTOSIS; BARRIERS; ABLATION
subject category
Chemistry; Science & Technology - Other Topics; Materials Science; Physics
authors
Marin, R; Skripka, A; Besteiro, LV; Benayas, A; Wang, ZM; Govorov, AO; Canton, P; Vetrone, F
our authors
Groups
acknowledgements
R.M., A.S., and L.V.B. contributed equally to this work. F.V. is grateful to the Natural Sciences and Engineering Research Council (NSERC) of Canada for supporting his research. P.C. gratefully acknowledges Ca' Foscari ADIR 2016. L.V.B. is thankful for support by China Postdoctoral Science Foundation (2017M622992). Z.W. was supported by National Basic Research Program of China (Project No. 2013CB933301) and National Natural Science Foundation of China (Project No. 51272038). A.B. thanks the Canadian Institutes of Health Research - Breast Cancer Society of Canada (CIHR-BCSC), for the support given to him through the Eileen Iwanicki Postdoctoral Fellowship on Breast Cancer Imaging, and he also thanks the European Commission as his participation in this project at its later stage received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska Curie Grant Agreement No. 709270 "TEMPTATION." A.S. is grateful to the Fonds de Recherche du Quebec - Nature et technologies (FRQNT) for financial support in the form of a scholarship for doctoral studies (Bourses de doctorat en recherche).