Track topics on Twitter Track topics that are important to you
Fluorescent carbon dots (CDs) are of interest as a promising alternative to quantum dots, partly because they do not include heavy metals. However, most CDs exhibit blue or green emission, while red-emitting CDs are required for a variety of applications. In the present work, CDs were synthesized by refluxing three phenylenediamine (PD) isomers with amino groups at different positions (o-PD, m-PD and p-PD) in diphenyl ether at 250 °C for 4 h. Upon dispersing the resulting CDs in eight solvents with different polarities, emission colors ranging from green to red were observed. Among these CDs, p-PD-derived CDs exhibited both the longest emission wavelength range, from 538 to 635 nm, and the highest absolute red photoluminescence quantum yield (PLQY) of 15%. Herein, the results are discussed based on a comparison of the polymerization processes of o-PD, m-PD and p-PD. This work demonstrated that the optimum reaction time was 2 h, which yields a p-PD-derived CD dispersion in methanol with red emission and an absolute PLQY as high as 18%. Additionally, the use of 1-decanol and deuterated methanol in place of methanol improved the maximum absolute PLQY to 25% and 36%, respectively. These improved values are attributed to reduced concentration quenching by suppression of π-π stacking interactions and inhibition of the nonradiative relaxation process through the vibration of OH groups, respectively.
This article was published in the following journal.
Name: Langmuir : the ACS journal of surfaces and colloids
A novel methodology to prepare stable aqueous dispersions of raw single- and multi-walled carbon nanotubes is reported, based on dispersions previously prepared in tetrahydrofuran containing a phenol ...
A new nanoprobe based on yellow-emissive carbon dots (Y-CDs) was developed for sensing full-range intracellular pH values. By using o-phenylenediamine as the raw material, Y-CDs with a quantum yield o...
We report a general design strategy for a new class of luminogens with dual-state emission (DSEgens) referring to be brightly emissive in both solution and solid and solvatochromism properties by con...
The application of fluorescent carbon dots in bio-imaging has huge positive significance in the field of biomedicine. By taking this advantage, herein we prepared nitrogen, sulfur and iodine doped car...
Mercury (II) ions (Hg), as one of the most toxic heavy metals, can cause irreversible damage to human health even at very low concentration due to its high toxicity and bioaccumulation. Herein, a faci...
The current knowledge of the pathophysiology of allergic contact dermatitis is based on the murine model. In this model, CD8+ T cells are effector cells, and CD4+ T cells regulate the re...
This type of study is called a radiolabeled study. For this study, LY3039478 (study drug) has been specially prepared to contain radiolabeled carbon [¹⁴C]. [¹⁴C] is a naturally occur...
Volume expansion is the cornerstone of perioperative hemodynamic optimization. The main objective of volume expansion is to increase and to maximize stroke volume. Despite national and int...
The purpose of this study is to evaluate the safety and tolerability of two carbon monoxide doses when administered as an inhaled gas for 1 hour in patients receiving kidney transplants.
Patients undergoing ERCP procedure with biliary stricture will have epithelial mucosa labeled with QRH-882260 fluorescence peptide that binds to EGFR. A custom mini-cholangioscope will be ...
Measurement of the intensity and quality of fluorescence.
An analytical method for detecting and measuring FLUORESCENCE in compounds or targets such as cells, proteins, or nucleotides, or targets previously labeled with FLUORESCENCE AGENTS.
Unsaturated derivatives of the ESTRANES with methyl groups at carbon-13, with no carbon at carbon-10, and with no more than one carbon at carbon-17. They must contain one or more double bonds.
C18 steroid with androgenic and anabolic properties. It is generally prepared from alkyl ethers of ESTRADIOL to resemble TESTOSTERONE but less one carbon at the 19 position.
A type of FLUORESCENCE SPECTROSCOPY using two FLUORESCENT DYES with overlapping emission and absorption spectra, which is used to indicate proximity of labeled molecules. This technique is useful for studying interactions of molecules and PROTEIN FOLDING.