Rare-earth-free up and down-conversion dual-emission carbon dots for Cu sensing.

In this work, up- and down-conversion dual-emission CDs without rare-earth (UD D-CDs) were synthesized using RhB and 1,4-Diaminoanthraquinone as precursors. The synthesized UD D-CDs exhibited dual emissions at 496 and 580 nm under 260 and 865 nm excitation, respectively. The fluorescence emission mechanism, including contributions from carbon nuclei, surface states, molecular states, and internal defect states, was discussed through the separation and purification of UD D-CDs.

The novel up/down-conversion dual-emission carbon dots for dual-channel ratiometric fluorescence detection of pH and Cu.

Up/down-conversion dual-emission carbon dots (U/D-CDs) are rare and have potential in analytical sensing. Herein, a kind of novel U/D-CDs was prepared successfully by a one-step solvothermal method. The prepared U/D-CDs exhibited similar dual-emission behaviors at excitation wavelengths of 300 nm and 680 nm, respectively.

One-step solvothermal synthesis of full-color fluorescent carbon dots for information encryption and anti-counterfeiting applications.

Multicolor fluorescent carbon dots (CDs) have received extensive attention due to their excellent fluorescence tunable performance. In this study, multicolor CDs with color tunable and high fluorescence quantum yields (QYs) were successfully prepared under the same conditions by a one-step solvothermal method using 2-aminoterephthalic acid (ATA) and Nile Blue A (NBA) as reaction reagents, achieving a wide color field coverage. Detailed studies on the relevant mechanisms have been carried out for blue, green and red CDs, indicating that the regulating mechanism of multicolor luminescence is determined by the size of the sp conjugated domains, which is due to the increase of particle size that causes an increase in the size of the sp conjugated domains, resulting in the narrowing of the band gap and the red-shift of the emission wavelength.

CRISPR/Cas12a-Mediated Aptasensor Based on Tris-(8-hydroxyquinoline)aluminum Microcrystals with Crystallization-Induced Enhanced Electrochemiluminescence for Acetamiprid Analysis.

Improving the electrochemiluminescence (ECL) efficiency of luminophores has always been the goal of the ECL field. Herein, a novel crystallization-induced enhanced ECL (CIE ECL) strategy was exploited to significantly enhance the ECL efficiency of metal complex tris-(8-hydroxyquinoline)aluminum (Alq). Alq monomers self-assembled and directionally grew to form Alq microcrystals (Alq MCs) in the presence of sodium dodecyl sulfate.

Dye-based dual-emission Eu-MOF synthesized by Post-modification for the sensitive ratio fluorescence visualization sensing of ClO.

As we all know, excessive hypochlorite will be transformed into highly toxic substances, while insufficient hypochlorite can not completely kill bacteria and viruses in water. Therefore, it is desirable to develop a new analytical method to detect ClO in environmental water. Here, a novel and simple fluorescence sensor was constructed for monitoring ClO by an effective strategy.

Potentially tunable ratiometric electrochemiluminescence sensing based on conjugated polymer nanoparticle for organophosphorus pesticides detection.

In general, suitable double luminophores and their coreactants are necessary for constructing electrochemiluminescence (ECL) ratio strategy. However, the complexity of matching double luminophores and the stability and repeatability problem suffered by introducing exogenous coreactant would greatly limit the application of ratio detection. An original single-luminophore-based ECL ratio sensing was developed excluding any exogenous coreactants in this work.

One-pot hydrothermal synthesis of Si-doped carbon quantum dots with up-conversion fluorescence as fluorescent probes for dual-readout detection of berberine hydrochloride.

Here, the high fluorescent silicon-doped carbon quantum dots (Si-CQDs) were prepared by a facile and one-pot hydrothermal assay using 3-aminopropyltrimethoxysilane as the carbon and silicon source. The prepared Si-CQDs exhibit favorable water-soluble, high-temperature resistance, acid resistance, alkali resistance, high ionic strength resistance, high photostability, film-forming ability and solid-state fluorescence. Compared to other Si-CQDs that have been reported, the prepared Si-CQDs show unique up-conversion fluorescence.

A highly sensitive dual-readout assay for perfluorinated compounds based CdTe quantum dots.

Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonate (PFOS) are two typical perfluorinated compounds (PFCs) that poss potential ecological toxicity. In this work, a fluorescence and resonance light scattering (RLS) dual-readout strategy for the detection of PFCs at picomole level based on the water-soluble CdTe quantum dots (CdTe QDs) has been proposed. It is found that the CdTe QDs exhibit a quenching in the presence of PFCs and thus serve as useful probes for PFCs.

Novel Ratiometric Electrochemiluminescence Biosensor Based on BP-CdTe QDs with Dual Emission for Detecting MicroRNA-126.

The electrochemiluminescence (ECL) ratiometric assay is usually based on two different ECL luminophores, and the choice of two suitable luminophores and shared co-reactant makes its construction challenging. The single-emitter-based ECL ratio mode could overcome the limitation of two luminophores and simplify the construction process, so it is an ideal choice. In this work, CdTe quantum dots (CdTe QDs) were modulated using black phosphorus (BP) nanosheet to simultaneously emit the cathodic and anodic ECL signals, and HO and tripropylamine (TPrA) served as the cathodic and anodic co-reactants, respectively.

Strategy to Synthesize Tunable Multiemission Carbon Dots and Their Multicolor Visualization Application.

Studies on multiemission fluorescent carbon dots (CDs) excited at one wavelength are extremely promising because of their label-free property, facile synthesis, multicolor visualization, and prevention of background interference. In this study, a novel template strategy to develop multiemission carbon dots (M-CDs) using fluorescent precursors has emerged. We attempted to elucidate the relationship between precursor substances and luminescence origins.

A design strategy of dual-ratiomentric optical probe based on europium-doped carbon dots for colorimetric and fluorescent visual detection of anthrax biomarker.

In this work, a novel dual-ratiometric optical probe based on europium-doped carbon dots (Eu-CDs) was developed for colorimetric and fluorescent visual sensing dipicolinic acid (DPA), a anthrax biomarker. Eu-CDs with recessive signals were prepared via thermal pyrolysis method. And the magenta appears when Eu-CDs coordinates with Eriochrome Black T (EBT).

A new dual-recognition strategy for hybrid ratiometric and ratiometric sensing perfluorooctane sulfonic acid based on high fluorescent carbon dots with ethidium bromide.

In this work, a novel strategy for perfluorooctane sulfonic acid (PFOS) detection was established by using a ratiometric nanosensor with the combination of fluorescence and second-order scattering (SOS). The practical ratiometric nanosensor was synthesized simply by mixing fluorescent dye ethidium bromide (EB) and nitrogen doped carbon dots (N-CDs) which was synthesized by a one-step hydrothermal method with Victoria Blue B, possessing three emission peaks at 472 nm, 560 nm and 600 nm under a single wavelength excitation of 280 nm, respectively. The EB served as the reference signal label, and the N-CDs, having response to the analytes, acted as the response signal label.

Upconversion photoluminescence analysis of fluoroquinolones.

The characteristics of the upconversion (UC) photoluminescence (PL) of fluoroquinolones (FQs) are reported here for the first time. Using UC PL, a simple, sensitive, and cost-effective method of determining FQs was developed that eliminated interference arising from biological background fluorescence and did not require UV light to excite the FQ (in contrast to downconversion PL), which is an advantage given that UV is potentially damaging to organisms. Ciprofloxacin (CPFX) and levofloxacin (LVFX), two important FQs, were studied.

Core-shell quantum dots coated with molecularly imprinted polymer for selective photoluminescence sensing of perfluorooctanoic acid.

A photoluminescence (PL) sensor based on core-shell quantum dots (QDs) coated with molecularly-imprinted polymer (MIP) shell was designed for the determination of perfluorooctanoic acid (PFOA) in water. PFOA is a persistent and bioaccumulating water contaminant whose detection is of great importance for ensuring safe water supplies. We demonstrate a simple method to fabricate CdTe@CdS QDs and then encapsulate them with a molecularly-imprinted silica film in a one-pot sol-gel reaction.

Preparation of mesoporous silica nanoparticles molecularly imprinted polymer for efficient separation and enrichment of perfluorooctane sulfonate.

As a persistent organic pollutant, perfluorooctane sulfonate has drawn a worldwide attention. In this contribution, a novel molecularly imprinted polymer based on mesoporous silica nanoparticles was prepared for efficient separation and enrichment of perfluorooctane sulfonate in water samples. The polymer was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and N adsorption/desorption experiments.

Highly selective fluorescent visual detection of perfluorooctane sulfonate via blue fluorescent carbon dots and berberine chloride hydrate.

As a kind of emerging persistent organic pollutants, perfluorooctane sulfonate (PFOS) and its salts have caused global ecosystem pollution. To develop rapid, sensitive and low-cost detection method of PFOS is of great importance. In this work, a novel sensing method has been proposed for the highly selective fluorescent visual detection of PFOS in aqueous solution based on carbon dots (CDs) and berberine chloride hydrate (BH).

Synthesis of the Cu-Doped Dual-Emission Fluorescent Carbon Dots and Its Analytical Application.

New Cu-doped dual-emission carbon dots (D-CDs) were synthesized rapidly and simply via a one-pot solvothermal method, and its special photoluminescence mechanism was studied. D-CDs have two fluorescence (FL) emission peaks under one-wavelength excitation and can be used as dual-signal sensor which is usually designed with two or more substances. The prepared CDs show excellent water solubility, photostability, salt tolerance, oxidation resistance, and special optical properties.

An erythrosin B-based "turn on" fluorescent sensor for detecting perfluorooctane sulfonate and perfluorooctanoic acid in environmental water samples.

Because of the serious harm to animals and the environment associated with perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), a rapid, sensitive and low-cost method for detecting PFOS and PFOA is of great importance. In this paper, a novel sensing method has been proposed for the highly sensitive detection of PFOS and PFOA in environmental water samples based on the "turn-on" switch of erythrosine B (EB)-hexadecyltrimethylammonium bromide (CTAB) system. In pH 8.

Preparation of magnetic molecularly imprinted polymers for the rapid and selective separation and enrichment of perfluorooctane sulfonate.

As a persistent organic pollutant, perfluorooctane sulfonate has drawn a great worldwide attention. In this contribution, a novel material of magnetic molecularly imprinted polymers, based on perfluorooctane sulfonate, as a template, molecule was prepared. The magnetic molecularly imprinted polymers were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometry.

High Sensitive and Selective Detection of PFOS with Resonance Light Scattering Technology Based on the Interaction with Victoria Blue B.

This report presents a simple, sensitive and selective victoria blue B (VBB)-based resonance light scattering (RLS) assay of perfluorooctane sulfonate (PFOS). In pH 6.0 KH2PO4-NaOH buffer solution, VBB can be protonated and reacts with PFOS through electrostatic interactions to produce ionic-association complexes.

One-Pot Hydrothermal Synthesis of Carbon Dots with Efficient Up- and Down-Converted Photoluminescence for the Sensitive Detection of Morin in a Dual-Readout Assay.

Blue luminescent carbon dots (CDs) with a high photoluminescence (PL) quantum yield (48.3 ± 5.3%) were prepared by the one-pot hydrothermal reaction of citric acid with poly(ethylenimine) (PEI).

A simple and highly sensitive assay of perfluorooctanoic acid based on resonance light scattering technique.

A simple, highly sensitive resonance light scattering (RLS) method for the detection of perfluorooctanoic acid (PFOA) has been developed based on the interaction with crystal violet (CV). It was found that PFOA can form complexes with CV in acid medium resulting in remarkable enhancement of the RLS intensity of the system. And the enhanced RLS intensities are in proportion to the concentration of PFOA in the range of 0.

Triple-wavelength overlapping resonance Rayleigh scattering method for facile and rapid assay of perfluorooctane sulfonate.

In the present study, a novel triple-wavelength overlapping resonance Rayleigh scattering (TWO-RRS) method had been well established to detect perfluorooctane sulfonate (PFOS). We found that crystal violet (CV) could react with PFOS to form 1:1 ion-association complex by electrostatic attraction and hydrophobic effect over a wide pH range (5.0∼11.

An eosin Y-based "turn-on" fluorescent sensor for detection of perfluorooctane sulfonate.

In this paper, a novel sensing method with a higher sensitivity of perfluorooctane sulfonate (PFOS) than perfluorooctanoic acid (PFOA) has been proposed detection of PFOS in aqueous solution replying on the "off-on" switch of eosin Y/polyethyleneimine (PEI)/PFOS fluorescence system due to the higher affinity of PEI to PFOS than eosin Y. In pH 7.0 Britton-Robinson buffer solution, eosin Y reacts with protonated PEI to form complex by electrostatic attraction, which leads to a strong fluorescence quenching of the eosin Y.

[Colorimetric assay of perfluorooctanesulfonate based on gold nanoparticles].

For the property of persistent, bioaccumulation and genetic toxicity, perfluorooctanesulfonate (PFOS) is classified as a sort of persistent organic pollutants (POPs). It is significant to develop a novel assay for the determination of PFOS. In this work, we create a new colorimetric assay for PFOS in which the positively-charged gold nanoparticles (AuNPs) work as a nano-probe.