Temperature-responsive nanomagnetic logic gates for cellular hyperthermia

abstract

While a continuous monitoring of temperature at the micro-and nano-scales is clearly of interest in many contexts, in many others a yes or no answer to the question did the system locally exceed a certain temperature threshold?'' can be more accurate and useful. This is the case of hard-to-detect events, such as those where temperature fluctuations above a defined threshold are shorter than the typical integration time of micro/nanothermometers and systems where fluctuations are rare events in a wide time frame. Herein we present the synthesis of iron selenide magnetic nanoplatelets and their use as non-volatile logic gates recording the near infrared (NIR) dose that triggers a temperature increase above a critical temperature around 42 degrees C in prostate cancer cell cultures. This use is based on the bistable behavior shown by the nanoplatelets below a magnetic phase transition at a tunable temperature TC and on their photothermal response under NIR light. The obtained results indicate that the synthesized nanomagnets may be employed in the future as both local heaters and temperature monitoring tools in a wide range of contexts involving systems which, as cells, are temperature-sensitive around the tunable T-C.

keywords

IRON; FE3SE4; PHASE

subject category

Chemistry; Materials Science

authors

Silva, RO; Pereira, RA; Silva, FM; Gaspar, VM; Ibarra, A; Millan, A; Sousa, FL; Mano, JF; Silva, NJO

Groups

G1 - Porous Materials and Nanosystems
G2 - Photonic, Electronic and Magnetic Materials
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials

Projects

Desenvolvimento de fontes de arrefecimento controladas remotamente para uma nanotermodinâmica aplicada (CoolPoint)

CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)

acknowledgements

We thank Manuel Martins for fruitful discussions during the early stages of this work. We acknowledge J. Linden for kindly providing us with the reference Fe3Se4 sample and Guillermo Antorrena for the XPS measurements. We also acknowledge Tera Analysis and Vladimir Podnos for kindly providing us with a professional version of QuickField (TM). This work was developed within the scope of the projects CoolPoint P2020-PTDC-CTM-NAN-4511-2014 and CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and co-financed by FEDER under the PT2020 Partnership Agreement. The work in Zaragoza was supported by the research grant MAT2014-54975-R from the Spanish Ministry of Science and Innovation. Access to advanced electron microscopy facilities received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 - ESTEEM2 (Integrated Infrastructure Initiative I3). This work was also supported by a STSM Grant from COST Action MP1306 and TD1402. RPOS, VMG, FLS and NJOS acknowledge FCT for the PD/BD/116850/2016, SFRH/BPD/119983/2016, IF/00222/2015 and IF/01533/2015 grants.