Lanthanide photochemistry has been frequently studied for its high luminescence intensity, narrow emission band, and stable luminescent lifetime decay. In the work presented here, nanoparticles prepared using an aerosolization process were derived from europium-based GUMBOS (Group of Uniform Material Based on Organic Salts). These nanoparticles were characterized using electron microscopy, X-ray photoelectron spectroscopy (XPS), absorbance, and photoluminescence spectroscopy. An average diameter of 39.5 ± 8.4 nm for our nanoparticles was estimated by use of electron microscopy. Absorbance, luminescence, and luminescence lifetime decay measurements indicate intense and steady luminescence, which suggests a multitude of possible applications for lanthanide-based GUMBOS, especially in sensory devices, OLEDs, and photovoltaic devices.

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A new kind of material called nanoGUMBOS, comprised entirely of cations and anions, has been developed by pairing various functional ions that exhibit fluorescence activity with biocompatible ions, in a process very much akin to that employed in ionic liquid chemistry. In the present study, spectral and biological properties of NIR absorbing nanoGUMBOS were evaluated using electron microscopy, dynamic light scattering, absorbance, thermal imaging, and live/dead fluorescence assays in conjunction with malignant MDA-MB-231 and non-malignant HS-578-BST epithelial human breast cells. The primary focus of this study was to maximize heat generation using NIR laser irradiation and minimize non-specific cytotoxicity using biocompatible constituent ions (e.g. amino acids, vitamins, or organic acids). Concurrently, in order to generate highly responsive nanomaterials for NIR-laser-triggered hyperthermia, optimization of the nanoparticle size, shape, and uniformity was carried out. Evaluation of data from hyperthermal studies of NIR absorbing nanoGUMBOS shows that these materials can achieve temperatures above the threshold for killing cancerous cells. Additionally, in vitro cell based assays demonstrated their promising hyperthermal effects on cancer derived epithelial cells.

The photothermal properties of several near-infrared-absorbing nanoparticles derived from group of uniform materials based on organic salts (GUMBOS) and composed of cationic dyes coupled with biocompatible anions are evaluated. These nanoparticles were synthesized using a reprecipitation method performed at various pH values: 2.0, 5.0, 7.0, 9.0, and 11.0. The cations for the nanoparticles derived from GUMBOS (nanoGUMBOS), [1048] and [1061], have absorbance maxima at wavelengths overlapping with human soft tissue absorbance minima. Near-infrared-absorbing nanoGUMBOS excited with a 1064 nm continuous laser led to heat generation, with an average temperature increase of 20.4 ± 2.7 °C. Although the [1061][Deoxycholate] nanoGUMBOS generated the highest temperature increase (23.7 ± 2.4 °C), it was the least photothermally efficient compound (13.0%) due to its relatively large energy band gap of 0.892 eV. The more photothermally efficient compound [1048][Ascorbate] (64.4%) had a smaller energy band gap of 0.861 eV and provided an average photothermal temperature increase of 21.0 ± 2.1 °C.

The intensities of the atomic lines Ha and Da produced in a high-frequency discharge in water vapor are measured to determine the deuterium content. A special spectrometer uses an interference filter and a Fabry-Perot interferometer for simultaneous recording of both intensities. Electronic calculation gives an observed intensity ratio which can be corrected via a calibration curve, thus yielding the deuterium content in percent. The relative accuracy of the method depends on the enrichment: above 1 % deuterium the relaltive limit of error is about ± 1 %, down to 0.3% deuterium it is better than ± 5%. A deuterium concentration of 0.03% can just be distinguished from normal water.