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Nitrogen–sulfur co-doped pink fluorescent carbon dots (N,S-CDs) with uniform structure were successfully synthesized by the one-step solvothermal method using sulfosalicylic acid and $o$-phenylenediamine as precursors and ethanol as solvent. Photophysical measurements indicated that N,S-CDs exhibited excitation independence and excellent optical stability, with the fluorescence quantum yield of 12.21% and the fluorescence lifetime of 7.07ns. The prepared N,S-CDs solution was estimated to be utilized as fluorescent ink for information encryption, and be used as a fluorescent sensor to detect trace water in organic solvents (anhydrous ethanol, DMF). Furthermore, broad linear detection ranges (0–10%), low limit of detection (e.g., 0.187% for ethanol, 0.179% for DMF) had been achieved with this method. Based on the UV–Vis absorption spectra and fluorescence lifetime evaluation, the proposed mechanism underlying the trace water detection capability of the synthesized carbon dots in organic solvents stems from the interplay between water and fluorophore molecules facilitated by dynamic quenching.

By combining synchronous fluorescence (SF) spectroscopy and fluorescence polarization (FP) technology, a new spectral technique, termed synchronous fluorescence polarization (SFP) can be obtained. It inherits the advantages of both, such as high sensitivity, less sample demand, rapid detection, and so on. This concept has been proposed before without implementation details. In this work, a detailed implementation scheme of the technology is proposed, including the hardware requirements of the instrument, the measurement and calculation of the instrument correction factor G-factor, the spectral acquisition, the removal of inner filter effect (IFE), the removal of solvent background and the calculation and analysis of anisotropy. Furthermore, exploring the mechanism of quantum dots (QDs) as fluorescent sensor to detect heavy metal ions was taken as an example to introduce the application of the SFP method. Through detecting SF anisotropy, the mechanism of QDs probing ${\text{Hg}}^{2+}$ ion was explained. If an appropriate fluorescent polarization enhancer is chosen, SFP can be used for quantitative detection. This work provides a specific implementation scheme of the SFP technology for the first time, which expands the application of fluorescence technology.

INDIA – South Asia waters harbor drug-resistant bugs.

JAPAN – Daiichi Sankyo initiates phase 3 ENSURE-AF study, investigating patients with atrial fibrillation undergoing cardioversion.

SINGAPORE – Scientists discover a number of novel genetic defects which cause esophageal cancer.

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SINGAPORE – Genome Institute of Singapore partners Nutricia Research to investigate human gut microbiome.

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THE PHILIPPINES – Biodiversity loss linked to outbreaks of diseases.

VIETNAM – Mosquito genes could be key to halting dengue spread.

EUROPE – Curetis obtains key patent for Unyvero™ technology.

NEPAL – Fly ash waste used as water purifier.

UNITED STATES – Researchers discover genetic markers that may predict when people with heart disease are likely to have heart attacks.

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This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn²⁺ ion.

Two pyrrolyl-BODIPY dyes with 3,5-di-$t$-butyl-4-hydroxyphenyl group were synthesized through stepwise S${}_{\text{N}}$Ar reactions of 3,5-dibromoBODIPYs, which were used as a fluorescent sensor for basic anions. The intermediate pyrrolyl-BODIPYs 2a–2b were regioselectively synthesized through an efficient S${}_{\text{N}}$Ar reaction between 3,5-dibromoBODIPY 1a and pyrroles. The target pyrrolyl-BODIPYs 3a–3b with a 3,5-di-$t$-butyl-4-hydroxyphenyl group at 3-position and a pyrrole substituent at 5-position were obtained through a second S${}_{\text{N}}$Ar reaction between pyrrolyl-BODIPYs 2a–2b and high steric hindrance 2,6-dibutylphenol in 90% and 88% yields, respectively. In contrast, the reaction between pyrrolyl-BODIPYs 2a–2b and phenol gave pyrrolyl-BODIPYs 3c–3d with phenoxy substituent at 3-position. These pyrrolyl-BODIPYs 3a–2d show strong, sharp absorptions (551–604 nm) and emissions (564–634 nm) with high fluorescence quantum yields up to 0.86 in dichloromethane. Importantly, the 3,5-di-$t$-butyl-4-hydroxyphenyl group of pyrrolyl-BODIPY 3a showed a turn-off fluorescent response toward fluoride anion.

In this study, a new blue-emitting carbon dot (CDs) was synthesized by a one-pot hydrothermal method. The uniform and transparent CDs solution can be obtained without separation. Its morphology, structural and properties information were also studied. Based on its fluorescence properties, the application in detection and composite film was explored. The CDs show good selectivity and sensitivity for dichromate ions and 4-nitrophenol (4-NP), the LOD were 6.22 and 8.14$\mu$M, respectively.