The system described in the study published in the journal Nano Letters , could be used to deliver drugs in a controlled manner in the body.

"Magnetic particles have the property that when subjected to an alternating magnetic field and heat dissipating heat in the environment. However, a hitherto unsolved aspect was to determine the temperature distribution in the vicinity of the particle when it is heated. To overcome this problem we have developed a new method of employing a molecule that degrades sensitive function of temperature, "says CSIC researcher Miguel Angel Garcia, the Institute of Ceramics and Glass.

thermosensitive molecule is placed at a fixed distance of the nanoparticle, as a spacer with a polymer, and is bonded to a fluorescent molecule. Optically measuring the amount of fluorescent molecules which are separated from the nanoparticles by applying a magnetic field, one can determine the temperature that has reached the heat-sensitive molecule and its distribution. According to the study, this method achieves a resolution less than nm, as obtained to date in these measures.

"The results have revealed that such small scales the thermal properties of materials are affected, and the heat transport follows a different laws which apply to macroscopic size materials," adds the CSIC researcher .

This work belongs MAGNIFYCO European project, which studies the use of magnetic nanoparticles for diagnosis and therapy of tumors, by releasing a controlled drug within the body. "If we replace the fluorescent molecule for a drug, this can be released in a controlled manner to make it as effective as possible and reduce the side effects," says Garcia.

size="1"> Andreas Riedinger, Pablo Guardia, Alberto Curcio, Miguel A. Garcia, Roberto Cingolani, Liberato Manna, Teresa Pellegrino. Local subnanometer Temperature Probing and Remotely Controlled Drug Release Based on Azo-Functionalized Iron Oxide Nanoparticles . DOI: 10.1021/nl400188q