Temperature and Phase Transition Sensing in Liquids with Fluorescent Probes

Abstract

Local environment of fluorescent dyes could strongly affects emission dynamics of the latter. In particular, both signal intensities and emission lifetimes are highly sensitive to solvent temperatures. Here, temperature-dependent behavior Rhodamine B fluorescence in water and ethanol solutions was experimentally investigated. Phase transition point between liquid water and ice was shown to have a dramatic impact on both in intensity (30-fold drop) and in lifetime (from 2.68 ns down to 0.13 ns) of the dye luminescence along with the shift of spectral maxima from 590 to 625 nm. At the same time, use of ethanol as solvent does not lead to any similar behavior. The reported results and approaches enable further investigations of dye-solvent interactions and studies of physical properties at phase transition points.

Hindered Isomerization at the Silica/Aqueous Interface: Surface Polarity or Restricted Solvation?

“…By contrast, water’s restricted mobility at a silica surfacealso apparent in simulationswould limit the solvent’s ability to promote C152 photoisomerization. Such behavior is similar to what one expects in solid matrices composed of polar materials and would be consistent with reports of “icelike” water at silica/aqueous interfaces . Experiments and simulations create conflicting narratives about the static dielectric constant of ice relative to bulk water, , but both theory and experiment show unequivocally that water reorientation dynamics at hydrophilic surfaces slows significantly from bulk limits .…”

“…Such behavior is similar to what one expects in solid matrices composed of polar materials and would be consistent with reports of "icelike" water at silica/aqueous interfaces. 24 Experiments and simulations create conflicting narratives about the static dielectric constant of ice relative to bulk water, 25,26 but both theory and experiment show unequivocally that water reorientation dynamics at hydrophilic surfaces slows significantly from bulk limits. 27 In vibrational spectroscopy experiments, highly structured water at a silica/aqueous interface is observed as a single broad feature centered at a relatively low frequency (3100 cm −1 ), very similar to the vibrational Raman spectrum of bulk ice.…”

Optothermal Needle‐Free Injection of Vaterite Nanocapsules

“…In order to ascertain the temperature induced in the particles upon illumination with femtosecond pulses we used fluorescence lifetime‐based thermometry, e.g. [ 79 , 80 ] The scheme of the experimental setup is shown in Figure 6 a .…”

In situ Microfluidic Cryofixation for Cryo Focused Ion Beam Milling and Cryo Electron Tomography

“…Rhodamine B is a commonly used probe for non-contact temperature measurements as its quantum yield, and subsequently fluorescence intensity, increases as the medium cools 47–49 . One recent report demonstrated Rhodamine B/DI water solution as a probe for the solid-liquid phase transition 50 . Fluorescence intensity of the Rhodamine B/DI water solution increased as the solution approached the freezing point, reaching a maximum just before the solid-liquid phase transition.…”