Oxygen-proof fluorescence temperature sensing with pristine C₇₀encapsulated in polymernanoparticles

Abstract

We report the first successful encapsulation of pristine fullerene C 70 in polymer nanoparticles with very low size polydispersity. We obtained water-dispersed polystyrene (PS) nanoparticles with diameters from 60 nm to 190 nm using a miniemulsion polymerization technique. Contrarily to pristine fullerenes, which are insoluble in most solvents and materials, the nanoparticles containing fullerene C 70 (PS-C 70 ) are stable in water and can be easily incorporated in different materials. When blended with polyacrylonitrile (PAN), a virtually oxygen-impermeable polymer, the PS-C 70 nanoparticles show a strong temperature dependence of the thermally activated delayed fluorescence (TADF) intensity and lifetimes, even when exposed to air. This is the first fluorescence temperature sensor based on TADF that can operate in the presence of oxygen. Unlike other fluorescence temperature sensors, our sensor material is insensitive to oxygen, has emission lifetimes in the millisecond range, and shows a strong emission intensity increase when the temperature increases. This sensor exhibits a very broad sensitivity in a working range from À75 C to at least 105 C (based on fluorescence intensity), surpassing the performance of other temperature fluorescence sensors at high temperatures.

Fluorescence of fullerene C70 in ionic liquids

“…[12]. Recently, fullerene C 70 was used as an outstanding fluorescence optical sensor for oxygen [13,14] and temperature [15,16]. Pristine fullerenes (C 60 , C 70 , C 76 , and higher fullerenes) are sparingly soluble in most non-chlorinated solvents, e.g., aliphatic and aromatic hydrocarbons [17].…”

Thermometry at the nanoscale

“…However, the thermometer sensitivity is not reported and no data are published to estimate it. These NPs are one of the few examples reported so far of cellular thermometers based on Ln , Ln ¼ Er, Tm) were also used for high-contrast intracellular fluorescence images of HeLa cells 64,68,124 and in vivo whole body nude mouse.…”

Optical sensing of aqueous boron based on polymeric hydroxytriphenylene derivatives

“…To improve solubility issues previously found for the unmodied HHTP sensor, we use a common strategy for increasing the water solubility of probes and sensors, consisting in coupling these to water soluble moieties or dispersible systems. 31,32 We introduce water soluble ethylene glycol groups in the HHTP core, and couple this with a water soluble poly(methacrylic acid) chain (PMAA).…”