resumo
The photoexcitation of materials results in the production of thermal energy (heat) under laser excitation and is an evolving field of research, prompted by the ever-growing demands in the fields of nanotechnology and nanomedicine. Understanding the radiation-to-heat conversion efficiency is, thus, important for the selection of the more suitable materials for photothermal therapeutic applications. To this regard, laser irradiation at near infrared frequencies are indispensable, offering deeper penetration depths in biological tissues, when compared with visible ones. Here, the molar extinction coefficients of SrF2:Yb3+/Er3+ upconverting nanoparticles with diameters 10 +/- 2 nm and 41 +/- 10 nm were calculated at 980 nm as 2.43 M-1 cm(-1) and 2.40 M-1 cm(-1), respectively. The corresponding photothermal conversion efficiencies are 32.0 +/- 1.0% and 11.5 +/- 0.8%, for the 10 nm and 41 nm diameter upconverting nanoparticles, respectively. The photothermal efficiency values of SrF2:Yb3+/Er3+ nanoparticles permit to prospect their future use as photothermal agents.
palavras-chave
PHOTOTHERMAL THERAPY; CANCER-CELLS; DRUG-DELIVERY; GOLD NANOCAGES; GRAPHENE OXIDE; NANOCRYSTALS; ABLATION; AGENT; NANOCOMPOSITES; NANORODS
categoria
Materials Science; Optics
autores
Balabhadra, S; Debasu, ML; Brites, CDS; Ferreira, RAS; Carlos, LD
nossos autores
Carlos Brites
Professor Auxiliar
Luís Carlos
Professor Catedrático
Maria Rute de Amorim e Sá Ferreira André
Vice-Diretor
Mengistie Leweyehu Debasu
Investigador
Sangeetha Balabhadra
Bolseiro de investigaçãoProjectos
LUMINET - European Network on Luminescent Materials (LUMINET)
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
SusPhotoSolutions - Soluções Fotovoltaicas Sustentáveis (SUSPHOTOSOLUTIONS)
agradecimentos
Financial support of Fundacao para a Ciencia e a Tecnologia (FCT) (PTDC/CTM-NAN/4647/2014 and POCI-01-0145-FEDER-016687), EC Marie Curie Initial Training Network LUMINET (316906) and COST-CM1403 Action is acknowledged. This work was partially developed in the scope of the project CICECO - Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. SB acknowledges Professor Marco Bettinelli and Laboratory of Solid State Chemistry from University of Verona, Italy, for the useful insights to prepare the nanoparticles. MLD and CDSB acknowledge, respectively, the post-doctoral FCT fellowship (SFRH/BPD/93884/2013) and the grant financed by the SusPhotoSolutions project (CENTRO-01-0145-FEDER-000005).