Catechol oxidase nanozyme based colorimetric sensors array for highly selective distinction among multiple catecholamines.

In order to effectively monitor multiple catecholamine (CA) neurotransmitters with extreme similar structures, a rapid, sensitive and selective detection strategy has become an urgent problem to be solved. In this paper, a novel colorimetric sensors array based on CuNCs protected by various ligands such as tannic acid, ascorbic acid and polymethylacrylic acid (CuNCs@TA, CuNCs@AA and CuNCs@PMAA) was constructed. All of these CuNCs could mimic catechol oxidase to selective catalyze catechol-type analogues (such as CAs) to corresponding quinones along with color changes.

NH-MIL-101(Fe) nanozyme-based dual-modality sensor for determination of alendronate sodium and study of two-dimensional correlation spectroscopy.

We developed a dual-modality sensing platform for ratiometric fluorescence and colorimetric determination of alendronate sodium (ALDS). This platform was performed by using a NH- MIL-101(Fe) as a peroxidase mimic. Since preferential complexing between Fe (active site for peroxidase) and ALDS, the production of 2,3-diaminophenazine (DAP, oxidized product of OPD) has been inhibited in the presence of HO.

Supramolecule self-assembly synthesis of amyloid phenylalanine-Cu fibrils with laccase-like activity and their application for dopamine determination.

Laccases are multicopper proteins for dioxygen-involved oxidation of a broad spectrum of organic compounds. I Novel amyloid-like phenylalanine-Cu (F-Cu(II)) fibrils were developed, which were obtained via supramolecular self-assembly of Cu and phenylalanine (F) under basic condition. The obtained amyloid-like fibrils represented highly periodic structure, of which the lattice unit was constructed via alternating hydrophobic (aromatic environment) and hydrophilic (both hydrogen bonding and Cu(II) coordination) interactions.

Synthesis of water-soluble, ultrabright Cu nanoclusters with core-shell structure via facile reduction approach for determination of 4-nitrophenol.

In this work, we reported a facile reduction approach for fabrication of water-soluble and ultrabright Cu nanoclusters with core-shell structure. A certain amount of reducing agent as NaBHwas introduced into the polyethyleneimine-stabilized Cu nanoclusters (CuNCs@PEI) system, which exhibited 4-fold fluorescence enhancement along with a blue shift of the emission peak. The variations of morphology, valence states and functional groups demonstrated that a Cu shell was formed surround CuNCs (defined as CuNCs-Cu@PEI), attributable to metal complex (PEI-Cuand PEI-Cu) reduction.

Nitrogen-terminated silicon nanoparticles obtained via chemical etching and passivation are specific fluorescent probes for creatinine.

A method is described here to prepare water-dispersible nitrogen-functionalized silicon nanoparticles (N-SiNPs). It consists of two steps, viz. etching of the oxidized shell of SiNPs and nitrogen-passivation of the exposed silicon.

11-Mercaptoundecanoic acid capped gold nanoclusters as a fluorescent probe for specific detection of folic acid a ratiometric fluorescence strategy.

A novel ratiometric fluorescence strategy is developed for specific detection of folic acid (FA) by using 11-mercaptoundecanoic acid protected gold nanoclusters (AuNCs@MUA). In this design, the fluorescence color of the probe can be switched among red, pink, violet and blue by varying the concentration of FA. AuNCs@MUA possesses strong fluorescence peaking at 612 nm (R-signal) and FA exhibits blue emissive auto-fluorescence at 446 nm (B-signal), showing a large emission shift of ∼170 nm.

Polyethyleneimine protected silver nanoclusters luminescence probe for sensitive detection of cobalt (II) in living cells.

A simple luminescence sensor, based on polyethyleneimine protected silver nanoclusters (AgNCs@PEI) is successfully fabricated via one-pot reduction method. The obtained AgNCs@PEI are characterized by high-resolution transmission electron microscopy (HR-TEM), Dynamic light scattering (DLS), transient and steady-state fluorescence, and UV-vis spectroscopy. The NCs show large Stocks-shift (∼130nm), high tolerability to extreme pH and high ionic strengths, and excellent photo-stability under UV irradiation, laying the basement for the practical applications.