Temperature-responsive nanomagnetic logic gates for cellular hyperthermia

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 °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 T C 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

Thermometry at the nanoscale using lanthanide-containing organic-inorganic hybrid materials

Non-invasive accurate thermometers with high spatial resolution and operating at sub-micron scales, where the conventional methods are ineffective, is currently a very active field of research strongly stimulated in the last couple of years by the challenging demands of nanotechnology and biomedicine. Here we report on the temperature operation range, spatial resolution and long-term stability of Eu3+/Tb3+ luminescent thermometers involving magnetic hybrid nanoparticles and di-ureasil thin films. (c) 2011 Elsevier B.V. All rights reserved