Sensitive and selective detection of chromium (VI) based on two-dimensional luminescence metal organic framework nanosheets via the mechanism integrating chemical oxidation-reduction and inner filter effect.

Two-dimensional luminescence metal organic framework nanosheets (LMOF) named NH-CuMOFs were synthesized using Cu (II) nodes coordinated with negatively charged 2-aminoterephthalic acid (NH-BDC) via a bottom-up strategy, which were first used as the fluorescent probes for the detection of chromium Cr (VI). The nanosheets possess stable fluorescence with the maximum emission wavelength of 436 nm at excitation of 338 nm that can be effectively quenched by hexavalent chromium Cr (VI). The NH-CuMOFs nanosheets show superior advantage over the linker of NH-BDC for the excellent selectivity to Cr (Ⅵ) without the interferences of other metal ions.

Universal Nanoplatform for Formaldehyde Detection Based on the Oxidase-Mimicking Activity of MnO Nanosheets and the In Situ Catalysis-Produced Fluorescence Species.

Formaldehyde (HCHO) pollution is a scientific problem of general concern and has aroused wide attention. In this work, a fluorometric method for sensitive detection of formaldehyde was developed based on the oxidase-mimicking activity of MnO nanosheets in the presence of -phenylenediamine (OPD). The MnO nanosheets were prepared by the bottom-up approach using manganese salt as the precursor, followed by the exfoliation with bovine serum albumin.

Self-Catalyzed Surface Reaction-Induced Fluorescence Resonance Energy Transfer on Cysteine-Stabilized MnO Quantum Dots for Selective Detection of Dopamine.

A simple one-step ultrasonic method was developed for the synthesis of luminescent MnO quantum dots (MnO QDs) in the presence of cysteine, in which cysteine acted as the exfoliating agent and stabilization ligand. The cysteine-stabilized MnO QDs (Cys-MnO QDs) possess a fluorescence quantum yield of 4.7%, and the fluorescence intensity of Cys-MnO QDs is sensitive to dopamine (DA).

Facile Preparation of MnO Quantum Dots with Enhanced Fluorescence via Microenvironment Engineering with the Assistance of Some Reductive Biomolecules.

MnO nanomaterials have aroused widespread attention because of their nanozyme activity, redox properties, good biocompatibility, and therapy-related activities. However, not many reports on self-luminescent MnO materials have been concerned to date, which greatly hampered their further development in various fields. In this paper, luminescent MnO quantum dots (MnO QDs) have been first prepared via a facile one-step ultrasonic method.

A dual (colorimetric and fluorometric) detection scheme for glutathione and silver (I) based on the oxidase mimicking activity of MnO nanosheets.

A fluorimetric and colorimetric method is described for the determination of glutathione (GSH) and silver (I). It is based on the use of MnO nanosheets that were prepared by solution mixing and exfoliation. They display oxidase-mimicking activity and can catalyze the oxidation of o-phenylenediamine (OPD) to form yellow 2,3-diaminophenazine (DAP) with an absorption maximum at 410 nm.

Colorimetric detection of ascorbic acid and alkaline phosphatase activity based on the novel oxidase mimetic of Fe-Co bimetallic alloy encapsulated porous carbon nanocages.

A novel catalyst of FeCo nanoparticles (FeCo NPs) incorporated porous nanocages (FeCo NPs@PNC) was first synthesized by encapsulating of FeCo alloy into ZIF-8 and further carbonation of the composite. The FeCo NPs@PNC displays enhanced intrinsic oxidase-like activity compared to the individual FeCo NPs and porous nanocages (PNC). The FeCo NPs@PNC can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to oxidized TMB (oxTMB) without HO, producing a blue color with a maximum absorption peak at 652 nm.

Colorimetric determination of ascorbic acid and the activity of alkaline phosphatase based on the inhibition of the peroxidase-like activity of citric acid-capped Prussian Blue nanocubes.

Colorimetric methods are described for the determination of ascorbic acid (AA) and alkaline phosphatase (ALP). Both assays are based on the inhibition of the peroxidase (POx)-like activity of Prussian Blue nanocubes (PB NCs) capped with citric acid. They catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) by HO to produce a blue color with an absorption maximum at 652 nm.

A novel biomimetic nanoenzyme based on ferrocene derivative polymer NPs coated with polydopamine.

In this paper, ferrocene derivative polymer nanoparticles (FcP NPs) with uniform size and good photostability was synthesized using 1,1'-ferrocene dicarboxylic acid as precursor and methanol as solvent. FcP NPs-PDA was further obtained by coating of polydopamine (PDA) on FcP NPs in tris-HCl (pH=8.5) buffer solution at room temperature in the presence of dopamine (DA).

miR-219 Cooperates with miR-338 in Myelination and Promotes Myelin Repair in the CNS.

A lack of sufficient oligodendrocyte myelination contributes to remyelination failure in demyelinating disorders. miRNAs have been implicated in oligodendrogenesis; however, their functions in myelin regeneration remained elusive. Through developmentally regulated targeted mutagenesis, we demonstrate that miR-219 alleles are critical for CNS myelination and remyelination after injury.