A pH visual sensing platform based on dual-emission chiral carbon dots for discrimination of normal/cancer cells and monitoring food freshness.

Accurate detection of pH is important in pathological processes and food freshness. Developing sensors of sensitive response and visualization for pH is highly demanded. In this work, Chiral carbon dots (CCDs) was synthesized via one-pot hydrothermal process using o-phenylenediamine and L-Tryptophan, which displayed circular dichroism (CD) signals at 200-255 nm and 255-300 nm.

Effect of different crystal forms of MnO quenchers on the sensitivity of copper nanoclusters and their use in acidphosphatase activity.

Highly stable copper nanocluster (CuNCs) with aggregation-induced emission (AIE) properties was synthesized. α-, β-, and γ- MnO were utilized as quenchers, with CuNCs fluorescence quenching of 48.9%, 91.

Detection of ascorbic acid by persistent luminescent nanoparticles based on CoOOH nanosheets modification.

Persistent luminescent nanomaterials (PLNPs) ZnGaO: Cr, Zr with high brightness and good dispersion were prepared by hydrothermal method. The PLNPs were used as luminescent units, and CoOOH nanosheets were used as quenching agents. Based on the fluorescence internal filtering effect, the luminescence of PLNPs were effectively quenched by CoOOH modification on the surface of PLNPs.

A ratiometric fluorescent probe with dual-targeting capability for heat shock imaging.

HSO is an important reactive sulfur species that maintains the normal physiological activities of living organisms and participates in a variety of redox homeostatic processes. It has been found that changes in HSO levels is closely related to the heat stroke phenomenon of the organism. Heat stroke causes damage to normal cells, which in turn causes damage to the body and even death.

Construction of nanohybrid Tb@CDs/GSH-CuNCs as a ratiometric probe to detect phosphate anion based on aggregation-induced emission and FRET mechanism.

The simple preparation of a nanohybrid of terbium-doped carbon dots/glutathione-capped copper nanoclusters (Tb@CDs/GSH-CuNCs) was for the first time developed for ratiometric detection of phosphate anion (Pi). Blue-emission of Tb@CDs can trigger non-luminescence of GSH-CuNCs for aggregation-induced emission (AIE) performance due to the strong reserved coordination capacity of Tb. Thus, Tb@CDs/GSH-CuNCs rapidly generated dual-emission signals at 630 nm and 545 nm by directly mixing the two individual materials via the AIE effect, alongside fluorescence resonance energy transfer (FRET) process.

Synthesis of molecularly imprinted polymers based on nitrogen-doped carbon dots for specific detection of chlortetracycline by reversed phase microemulsion method.

Among the tetracycline antibiotics, chlortetracycline (CTC) is the most frequently used antibiotic except for tetracycline (TC) for enhancing the ability of the organism to fight bacterial infections. The poor metabolism and degradability of CTC can cause serious health effects. Most studies have focused on the detection and analysis of TC, and research on CTC is relatively scarce.

Ce/Ce as the switch of AIE-copper nanoclusters for highly selective detection of ascorbic acid in soft drinks.

An ultrasimple "turn-on" sensor for indirectly detecting ascorbic acid (AA) was prepared using N-acetyl-L-cysteine stabilized copper nanoclusters (NAC-CuNCs) via the AIE (aggregation-induced emission) effect controlled by Ce/Ce redox reaction. This sensor fully utilizes the different properties of Ce and Ce. Non-emissive NAC-CuNCs were synthesized by a facile reduction method.

A review: Small organic molecule dual/multi-organelle-targeted fluorescent probes.

In recent years, the dual/multi-organelle-targeted fluorescent probe based on small organic molecules has good biocompatibility and can visualize the interaction between different organelles, which has attracted much attention. In addition, these probes can also be used to detect small molecules in the organelle environment, such as active sulfur species (RSS), reactive oxygen species (ROS), pH, viscosity and so on. However, the review of dual/multi-organelle-targeted fluorescent probe for small organic molecules lacks a systematic summary, which may hinder the development of this field.

Synthesis of fluorescent probe based on molecularly imprinted polymers on nitrogen-doped carbon dots for determination of tobramycin in milk.

Tobramycin (TOB) plays a considerable role in combating milk spoilage and preventing disease in dairy cows. However, overuse of TOB can lead to nephrotoxicity, ototoxicity, neuromuscular blockade, and hypersensitivity reactions. Here, nitrogen-doped carbon dots (N-CDs) were prepared with ethylenediamine and citric acid, then molecularly imprinted layers were obtained by imprinting of surface on the N-CDs to prepare Nitrogen-doped carbon dot-based molecularly imprinted polymers (N-CDs@MIPs).

Ce-induced Fluorescence Amplification of Copper Nanoclusters Based on Aggregation-induced Emission for Specific Sensing 2,6-pyridine Dicarboxylic Acid.

A straightforward, cost-effective and biocompatible reduction approach was applied to fabricate soluble but non-luminous glutathione-stabilized copper nanocluster (GSH-CuNCs). Surprisingly, as high as 1 × 10 times fluorescence enhancement was acquired when Ce was injected at an extremely low concentration of only 18 µM. Ce outperformed other rare-earth metal ions in terms of inducing fluorescence amplification of the non-luminous GSH-CuNCs.

A novel ratiometric sensor prepared based aggregation-induced emission for ultrafast detection of SO derivatives in food samples and living cells.

As one of the gaseous signaling molecules, aberrant levels of SO are usually associated with many diseases. it is of great significance to develop sensitive methods for detection SO on real. In this paper, a D-π-A near-infrared aggregation-induced fluorescent probe (DPA-CN) was built using diphenylamino-4-benzaldehyde and malononitrile for sensing SO.

Novel ratiometric probe based on the use of rare earth-carbon dots nanocomposite for the visual determination of doxycycline.

Rare earth-carbon dots (RE-CDs) hybrid nanomaterials with the merits of both RE and CDs have rapidly emerging as highly promising functional materials in biochemical analysis. In this work, a new kind of water-soluble RE-CDs nanocomposite (CDs@CaF:Eu) was developed for the ratiometric determination of doxycycline (DOX). The CDs@CaF:Eu under the excitation at 365 nm displayed blue emission of CDs at 440 nm and no obvious emission of Eu.

A novel AIE active NIR fluorophore based triphenylamine for sensing of Hg and CN and its multiple application.

New strategies still need to be proposed that can be used to sense and remove toxic environmental pollutants in a sensing system. In this research, a novel NIR fluorescence sensor 1 was designed and prepared with aggregation induced emission (AIE) property. The fluorescence intensity of the sensor 1 in DMSO/HO mixed solvent was changed along with the proportion of water.

A large-Stokes-shift fluorescent probe for Zn based on AIE, and application in live cell imaging.

A fluorescence-enhanced sensor based on aggregation-induced emission (AIE) was synthesized using a di(2-picolyl)amine (DPA) group as a highly selective metal chelating agent for Zn. The combination of the probe and Zn was achieved in an environment where the volume fraction of water was 90%, giving the probe good biocompatibility, and a large Stokes shift (100 nm) occurred after Zn was combined with the probe. The obvious color change makes the probe visible to the naked eye, and gives it a high signal-to-noise ratio, and high contrast, and minimizes self-absorption.

Using zinc ion-enhanced fluorescence of sulfur quantum dots to improve the detection of the zinc(II)-binding antifungal drug clioquinol.

A turn on-off fluorometric assay for clioquinol (CQ) is described here. It is based on modulation of the fluorescence of sulfur quantum dots (SQDs; best measured at excitation/emission wavelengths of 360/426 nm) by using the Zn-CQ affinity pair. Although the fluorescence enhancement effect of Zn on SQDs was not obvious, a good quenching modulation effect was observed in the presence of CQ.

An AIE active pyrene based fluorescent probe for selective sensing Hg and imaging in live cells.

A novel fluorescence probe pyrene based derivatives (1) with aggregation induced emission (AIE) properties was synthesized by an easy procedure. The probe 1 was characterized by UV-vis, Fluorescent, NMR, MS, SEM etc. It displayed high sensitivity and selectivity to Hg compared with other metal ions in HO/DMF solvent and the detection limit was 4.

Aggregation-induced phosphorescence quenching method for the detection of picric acid based on melamine-passivated Mn-doped ZnS quantum dots.

Melamine (MA)-passivated Mn-doped ZnS quantum dots (QDs) were synthesized by a hydrothermal method. The MA-passivated QDs can form a charge-transfer complex with picric acid (PA) at 80 °C, thereby quenching the phosphorescence of the QDs. A sensitive method for detecting PA was established based on this principle of phosphorescence quenching.

Preparation of metal-organic framework UiO-66-incorporated polymer monolith for the extraction of trace levels of fungicides in environmental water and soil samples.

A zirconium terephthalate metal-organic framework-incorporated poly(N-vinylcarbazole-co-divinylbenzene) monolith was fabricated in a capillary by a thermal polymerization method. The optimized monolith had a homogeneous structure, good permeability, and stability. The monolith could be used for the effective enrichment of fungicides through π-π interactions, electrostatic forces, and hydrogen bonds.

Determination of cholic acid in body fluids by β‑cyclodextrin-modified N-doped carbon dot fluorescent probes.

An easy, dependable, and sensitive cholic acid activity experiment was designed based on β‑cyclodextrin-modified carbon dot (β‑CD-CD) nanoprobes with specific host-guest recognizing ability and photoelectron transfer capability. The β‑CD-CD nanoprobes were characterized by infrared, ultraviolet-visible, and fluorescence spectroscopy and transmission electron microscopy. The fluorescence of the probes under optimized conditions linearly responded to cholic acid concentration from 0 to 650 μmol·L with a detection limit of 25 nmol·L.

Aptamer based fluorometric sulfamethazine assay based on the use of graphene oxide quantum dots.

The authors have developed a homogeneous "off-on" fluorometric method for the determination of the antibiotic sulfamethazine (SMZ). Aptamer against SMZ was labeled with graphene oxide quantum dots upon which the Graphene oxide quenched the blue fluorescence of the GOQDs. On addition of SMZ, the aptamers will bind SMZ and this will cause the release of GOQDs.

An active fluorescent probe based on aggregation-induced emission for intracellular bioimaging of Zn and tracking of interactions with single-stranded DNA.

A novel dual-sensing fluorescence probe L was designed and synthesized for highly selective and sensitive detection of Zn and DNA. The probe L achieved a detection limit of 3.8 nM for Zn, which is lower than the acceptable level of Zn in living cells.

Cu modulated nitrogen-doped grapheme quantum dots as a turn-off/on fluorescence sensor for the selective detection of histidine in biological fluid.

A highly sensitive sensor for detection of histidine (His) based on the nitrogen-doped graphene quantum dots (N-GQDs)-Cu system has been designed. The N-GQDs were synthesized by one-step hydrothermal approach according to previous report. The fluorescence of N-GQDs can be effectively quenched by Cu due to the binding between Cu and functional groups on the surface of N-GQDs.

Poly(methacrylic acid-ethylene glycol dimethacrylate-N-vinylcarbazole) monolithic column for the enrichment of trace benzodiazepines from urine and beer samples.

A sensitive microextraction method based on a new poly(methacrylic acid-ethylene glycol dimethacrylate-N-vinylcarbazole) monolithic capillary column, coupled with gas chromatography and electron capture detection, was established for the determination of three benzodiazepines (estazolam, alprazolam, and triazolam) in urine and beer samples. Owing to the abundant π electrons and polar surface of N-vinylcarbazole, N-vinylcarbazole-incorporated monolith showed a higher extraction performance than neat poly(methacrylic acid-ethylene glycol dimethacrylate) because of the enhanced π-π stacking interactions derived from the π-electron-rich benzene groups from N-vinylcarbazole. The monolith exhibited a homogeneous and continuous structure, good permeability, and a long lifetime.

Determination of tetracyclines in bovine milk using laccaic acid-loaded magnetite nanocomposite for magnetic solid-phase extraction.

An efficient magnetic sorbent of laccaic acid-loaded magnetite nanocomposite was successfully synthesized for extraction and preconcentration of tetracyclines (TCs) from bovine milk sample. The synthesized nanocomposite was characterized by scanning electron microscopy and Fourier transform-infrared spectroscopy. Determination of the extracted TCs was performed by high performance liquid chromatography.