Organocatalytic Dehydration of Fructose-Based Carbohydrates into 5-Hydroxymethylfurfural in the Presence of a Neutral Inner Salt.

A series of organic sulfonate inner salts, viz., aprotic imidazolium- and -based zwitterions bearing sulfonate groups (-SO), were synthesized for the catalytic conversion of fructose-based carbohydrates into 5-hydroxymethylfurfural (HMF). The dramatic cooperation of both the cation and anion of inner salts played a crucial role in the HMF formation.

Fe-Ni metal-organic frameworks with prominent peroxidase-like activity for the colorimetric detection of Sn ions.

Fe-Ni-MOFs with different amounts of Fe are synthesized through a two-step template etching method. Kinetic analysis indicates that Fe-Ni-MOF exhibits prominent intrinsic peroxidase-like activity, which could catalytically oxidize 3,3',5,5'-tetramethylbenzidine (TMB) to produce oxidized TMB (oxTMB) with a blue color. As a peroxidase-mimicking MOF, Fe-Ni-MOF with its efficient stable catalysis properties is demonstrated to allow a sensitive colorimetric assay for Sn2+ ions.

Nitrogen-doped carbon dots-VO nanobelts sensing platform for sensitive detection of ascorbic acid and alkaline phosphatase activity.

In this work, the as-prepared VO nanobelts can sensitively quench the fluorescence of nitrogen-doped carbon dots (N-CDs) based on the inner filter effect (IFE). In the presence of ascorbic acid (AA), the fluorescence of N-CDs can recover through the redox reaction between VO nanobelts and AA. Meanwhile, in the presence of both alkaline phosphatase (ALP) and ascorbyl-2-phosphate (AAP), the fluorescence of N-CDs can also restore since AAP can be hydrolyzed into AA by ALP.

A novel anodic electrochemiluminescence behavior of sulfur-doped carbon nitride nanosheets in the presence of nitrogen-doped carbon dots and its application for detecting folic acid.

The application of carbon dots as a coreactant for Ru(bpy) (where bpy is 2,2'-bipyridine) electrochemiluminescence (ECL) has been widely studied. However, the high cost of Ru(bpy) and its derivatives has prohibited its widespread use in ECL biosensors. Herein, a novel anodic ECL system based on sulfur-doped graphitic carbon nitride nanosheets (S-g-CN NSs) and nitrogen-doped carbon dots (N-CDs) is presented.

Nitrogen-doped-carbon-coated hexagonal cobalt oxyhydroxide/reduced graphene oxide nanocomposite for sensitive and selective detection of nitrite in human hepatoma cells.

Selective and sensitive determination of nitrite is of great importance in practical application. In the present work, a novel nitrite sensing platform was built based on the fabrication of nitrogen-doped-carbon-coated hexagonal cobalt oxyhydroxide (CN@CoOOH) on reduced graphene oxide (RGO) using zeolitic imidazolate framework (ZIF)-67 as a precursor. The CN@CoOOH/RGO nanocomposite was confirmed by UV-visible spectroscopy, Fourier transform infrared spectroscopy, x-ray photoelectron spectrum, transmission electron microscopy, scanning electron microscopy, and x-ray diffraction.

Selective oxidation of glycerol to tartronic acid over Pt/N-doped mesoporous carbon with extra framework magnesium catalysts under base-free conditions.

N-Doped mesoporous carbons (NMCs) with extra framework magnesium were prepared by a one-pot method and used as supports for Pt catalysts. The surface basicity of NMC improved in the presence of extra framework magnesium (e.g.

Dehydration of Glucose to 5-Hydroxymethylfurfural Using Nb-doped Tungstite.

Dehydration of glucose to 5-hydroxymethylfurfural (HMF) remains a significant problem in the context of the valorization of lignocellulosic biomass. Hydrolysis of WCl6 and NbCl5 leads to precipitation of Nb-containing tungstite (WO3 ⋅H2 O) at low Nb content and mixtures of tungstite and niobic acid at higher Nb content. Tungstite is a promising catalyst for the dehydration of glucose to HMF.