[Ga3+8Sm3+2, Ga3+8Tb3+2] Metallacrowns are Highly Promising Ratiometric Luminescent Molecular Nanothermometers Operating at Physiologically Relevant Temperatures

Abstract

Nanothermometry is the study of temperature at the submicron scale with a broad range of potential applications, such as cellular studies or electronics. Molecular luminescent- based nanothermometers offer a non- contact means to record these temperatures with high spatial resolution and thermal sensitivity. A luminescent- based molecular thermometer comprised of visible- emitting Ga3+/Tb3+ and Ga3+/Sm3+ metallacrowns (MCs) achieved remarkable relative thermal sensitivity associated with very low temperature uncertainty of Sr=1.9- %- K- 1 and δT<0.045- K, respectively, at 328- K, as an aqueous suspension of polystyrene nanobeads loaded with the corresponding MCs. To date, they are the ratiometric molecular nanothermometers offering the highest level of sensitivity in the physiologically relevant temperature range.Metallacrown- based thermometry: Mixtures of luminescent Ga3+/Tb3+ and Ga3+/Sm3+ metallacrowns proved to be highly sensitive luminescent molecular thermometers. These were placed in polystyrene nanobeads for aqueous stabilization and demonstrate the promise of a molecular approach to nanothermometry.