Thermalization of Fluorescent Protein Exciton-Polaritons at Room Temperature

Fluorescent proteins (FPs) have recently emerged as a serious contender for realizing ultra-low threshold room temperature exciton-polariton condensation and lasing. Our contribution investigates the thermalization of FP microcavity exciton-polaritons upon optical pumping under ambient conditions. We realize polariton cooling using a new FP molecule, called mScarlet, coupled strongly to the optical modes in a Fabry-Pérot cavity. Interestingly, at the threshold excitation energy (fluence) of ∼9 nJ/pulse (15.6 mJ/cm2 ), we observe an effective temperature, Teff ∼350 ± 35 K close to the lattice temperature indicative of strongly thermalized exciton-polaritons at equilibrium.
This efficient thermalization results from the interplay of radiative pumping facilitated by the energetics of the lower polariton branch and the cavity Q-factor. Direct evidence for dramatic switching from an equilibrium state into a metastable state is observed for the organic cavity polariton device at room temperature via deviation from the Maxwell-Boltzmann statistics at k = 0 above the threshold. Thermalized polariton gases in organic systems at equilibrium hold substantial promise for designing room temperature polaritonic circuits, switches, and lattices for analog simulation.

Fluorescent Genetic Tools for Studying Brown Fat Development and Function in Mice

Techniques to trace and isolate brown adipocyte precursor and adipocytes during development and disease are essential to fully understand brown adipose tissue development and function. Here we report several protocols using the R26R-mTmG reporter mice in thermogenic tissues based on confocal microscopy and fluorescence based flow cytometry. These techniques may be useful to understand the influence of genetic or environmental alterations in brown adipocyte precursors and adipocyte biology.

Nitrogen and sulfur co-doped carbon dot-based ratiometric fluorescent probe for Zn 2+ sensing and imaging in living cells

A near-infrared nitrogen and sulfur co-doped carbon dot (N,S-CD)-based ratiometric fluorescent probe is proposed that is synthesized via hydrothermal approach using glutathione and formamide as precursor for sensing and imaging of Zn2+. The prepared N,S-CDs facilitate binding with Zn2+ owing to N and S atom doping. The ratio (I650/I680) of fluorescence intensity at 650 nm and 680 nm increased with the concentrations of Zn2+ when the excitation wavelength was 415 nm. The linearity range was 0.01 to 1.0 μM Zn2+with a detection limit of 5.0 nM Zn2+. The proposed probe was applied to label-free monitoring of Zn2+ in real samples and fluorescent imaging of Zn2+ in living cells, which confirmed its promising applications.

A ratiometric fluorescent sensor for tetracyclines detection in meat based on pH-dependence of targets with lanthanum-doped carbon dots as probes

Although some ratiometric fluorescent sensors have been reported to detect tetracyclines, most of ratiometric fluorescent sensors were established based on europium ion with a narrow linear range. In this work, a ratiometric fluorescent sensor for tetracyclines detection was established based on the dual-emission lanthanum-doped carbon dots (La-CDs) as probes combining with the characteristic pH-response of tetracyclines. The fluorescence intensity of tetracyclines will be enhanced in high pH, and the emission peak of tetracyclines overlapped with the peak of probes.
The superposition effect of tetracyclines and probes at 515 nm greatly improved the sensitivity of the ratiometric fluorescent sensor and widened the detection range, and linear ranges for oxytetracycline (OTC) and tetracycline (TC) were respectively 0.00-805.20 μM and 0.00-1039.50 μM. Moreover, the preparation procedure of the La-CDs was simple and time saving and the coupling agent was not required. A comparison of La-CDs with undoped carbon dots (un-CDs) showed that the optical performance and sensing performance of La-CDs were improved. In addition, a portable paper sensor with La-CDs as probes was preliminarily explored in this work, and the sensor has been applied to detect OTC and TC in pork and fish with satisfactory results.

Utilization of N,S-Doped Carbon Dots as a Fluorescent Nanosensor for Determination of Cromolyn Based on Inner Filter Effect; Application to Aqueous Humor

A simple and eco-friendly hydrothermal technique is used to prepare water soluble N and S co-doped carbon quantum dots probe (N,S-CQDs) from thiosemicarbazide and citric acid. Several characterization techniques were performed in order to ensure well- synthesis of highly luminescent N,S-CQDs. The prepared probe exhibited analytical potential as optical nanosensor for the spectrofluorimetric determination of cromolyn sodium (CRO) in its pharmaceutical dosage forms and aqueous humor. The emission intensity of the synthesized N,S-CQDs was measured at 411 nm after excitation at 345 nm.
Addition of increasing concentrations of CRO to N,S-CQDs led to quenching of its fluorescence intensity. CRO was investigated within wide concentration range of 10.0 to 150.0 μM with limit of detection of 2.0 μM and limit of quantification of 6.0 μM. The quenching of fluorescent N,S-CQDs occurs through inner filter effect (IFE). The developed spectrofluorimetric method was successfully optimized and validated according to International Council of Harmonization (ICH). Method greenness is proved through using both Eco-scale and AGREE approaches.

A magneto-controlled biocatalytic cascade with a fluorescent output

A biocatalytic cascade based on concerted operation of pyruvate kinase and luciferase with a bioluminescent output was switched reversibly between low and high activity by applying an external magnetic field at different positions or removing it. The enzymes participating in the reaction cascade were bound to magnetic nanoparticles to allow their translocation or aggregation/dispersion to be controlled by the magnetic field. The reaction intensity, measured as the bioluminescent output, was dependent on the effective distances between the enzymes transported on the magnetic nanoparticles controlled by the magnets.

Fluorescent

FPAK-3058--9K Spherotech 9X1 mL 675.6 EUR

Fluorescent Particles

FP-10056-10 Spherotech 10 mL 888 EUR

Fluorescent Particles

FP-10056-2A Spherotech 2X1 mL 310.8 EUR

Fluorescent Particles

FP-2054-2 Spherotech 2 mL 230.4 EUR

Fluorescent Particles

FH-10056-10 Spherotech 10 mL 1022.4 EUR

Fluorescent Particles

FH-3056-10 Spherotech 10 mL 802.8 EUR

Fluorescent PAK Blue

FP-0567-2 Spherotech 2 mL 218.4 EUR

LAMP Fluorescent Dye

RP001-01 Vazyme 100 μl 15.5 EUR

Fluorescent Agent-5

F597823 Toronto Research Chemicals 10mg 334 EUR

Lamp Fluorescent Tube

LAM3218 Scientific Laboratory Supplies EACH 12.95 EUR

Fluorescent sensor, ANQ

9695-25 Biovision each 810 EUR

Fluorescent sensor, ANQ

9695-5 Biovision each 248.4 EUR

Fluorescent Protein Set

K816-6-100 Biovision each 1488 EUR

Fluorescent 100 bp DNA Ladder

M-234L Jena Bioscience GmbH 5 x 500µl 288.4 EUR

Fluorescent 100 bp DNA Ladder

M-234S Jena Bioscience GmbH 500µl 72.1 EUR

Fluorescent 200 bp DNA Ladder

M-235L Jena Bioscience GmbH 5 x 500µl 276.9 EUR

Fluorescent 200 bp DNA Ladder

M-235S Jena Bioscience GmbH 500µl 69.2 EUR

Fluorescent 500 bp DNA Ladder

M-236L Jena Bioscience GmbH 5 x 500µl 207.7 EUR

Fluorescent 500 bp DNA Ladder

M-236S Jena Bioscience GmbH 500µl 52 EUR

Cyan Fluorescent Protein

30R-2808 Fitzgerald 100 ug 462 EUR

Cyan Fluorescent Protein

4996-100 Biovision each 451.2 EUR

Cyan Fluorescent Protein

4996-1000 Biovision each 2865.6 EUR

Cyan Fluorescent Protein

4996-5000 Biovision each 7824 EUR

Fluorescent Particle Kit

FX-3552-6K Spherotech 6x1 mL 432 EUR

A coumarin-based fluorescent probe for NIR imaging-guided photodynamic therapy against S. aureus-induced infection in mouse models

A coumarin-based viscosity-responsive fluorescent probe (HZAU800) was designed and synthesized. The probe, containing a strong electron-donating and rigid group on the 7-position of coumarin and a rhodamine derivative containing an oxonium ion on 3-position, could not only shift the emission wavelength to near-infrared region (NIR, λem = 800 nm) but also deliver a good PDT effect due to its high rigid planarity.
The NIR fluorescence of HZAU800 can be lighted up in the S. aureus-infected region due to its high viscous environment. Under the laser’s irradiation at 690 nm, the PDT effect was effectively triggered up, and the antibacterial evaluation in vitro and in vivo was successfully carried out. This study not only offers a new strategy for constructing coumarin-based phototherapy agents but also facilitates the exploration of the next generation of antibacterial materials based on coumarin architectures.

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