This work presents a novel technique to measure the temperature in the vicinity (~3.5 nm) of a remotely heated, ultra-small gold nanoparticle. The temperature measurement is carried out employing fluorescent thermometry and core/shell CdSe quantum dots as fluorescent temperature sensors. The quantum dots are conjugated to 1.4 nm gold particle using standard conjugation techniques. First, temperature calibration is performed on water based solutions of pure quantum dots, and quantum dots conjugated with gold nanoparticles. During calibration the wavelength maxima of fluorescent intensity is measured as function of specimen temperature. After that, the specimen is placed in alternating electromagnetic field where gold particles start to harvest energy. While the electromagnetic field is being applied, the temperature of quantum dots is recorded. Three materials systems are tested in the presence of the applied electromagnetic field, namely water based suspensions of quantum dots, suspensions of quantum dots conjugated with nanogold and suspensions of quantum dots mixed with gold particles. The later is used to determine the bulk heating of the specimen. The results indicate ~10oC local temperature rise above the bulk temperature.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2008: Life Sciences, Medicine & Bio Materials – Technical Proceedings of the 2008 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: June 1, 2008
Pages: 252 - 255
Industry sectors: Advanced Materials & Manufacturing | Medical & Biotech
Topicss: Biomaterials, Materials Characterization & Imaging