Ratiometric sensor based on Ag-mediated luminescence of Tb-DNA complexes for visual detection of 4-aminophenol.

Development of accurate, convenient and portable methods for monitoring 4-aminophenol (4-AP) is extremely important because of its strong toxicity. Here, a ratiometric fluorescence sensor based on Ag-enhanced luminescence of Tb-DNA complexes has been presented for the detection of 4-AP. The luminescence of Tb-DNA complexes is enhanced about 30 times by Ag, which can trigger energy transfer from DNA to Tb more efficiently.

Copper-based fluorescent nanozyme used to construct a ratiometric sensor for visual detection of thiophanate methyl.

Although nanozyme has shown great potential in designing fluorescent assays for pesticide residue, most of them are based on single emission, thus affecting the detection accuracy. Herein, a copper-based fluorescent nanozyme (Cu-BH) synthesized with dual-ligand, integrating fluorescence and oxidase-mimic into one spherical nanomaterial, was used firstly to establish a ratiometric approach for visual detection of thiophanate methyl (TM). Cu-BH possesses excellent oxidase-like activities, triggering the oxidation of colorless o-phenylenediamine (OPD) into yellow luminescent products (oxOPD, λem = 564 nm).

Simultaneous and dynamic measurement of Schisandrol A changes in rat blood and brain and its comparative pharmacokinetic study in control and Parkinson's disease rats by dual-probe in vivo microdialysis.

Schisandrol A (SchA) is the main active ingredient of Schisandra chinensis (Turcz.) Baill., which is a famous traditional Chinese herbal medicine.

Ratiometric fluorescence assay for sulfide ions with fluorescent MOF-based nanozyme.

A novel ratiometric fluorescence strategy for sulfide ions (S) analysis has been developed using metal-organic framework (MOF)-based nanozyme. NH-Cu-MOF displays blue fluorescence (λem = 435 nm) originating from 2-amino-1,4-benzenedicarboxylic acid ligand. Besides, it possesses oxidase-like activity due to Cu node, which can trigger chromogenic reaction.

Ratiometric fluorescence sensing of formaldehyde in food samples based on bifunctional MOF.

A new fluorescence strategy was described for ratiometric sensing of formaldehyde (FA) with bifunctional MOF, which acted as a fluorescence reporter as well as biomimetic peroxidase. With the assistance of HO, NH-MIL-101 (Fe) catalyzes the oxidation of non-luminescent substrate o-phenylenediamine (OPD) to produce fluorescent product (oxOPD) with the maximum emission at 570 nm. Besides, intrinsic fluorescence of MOF (λem = 445 nm) was quenched by oxOPD through inner filter effect (IFE).

CoS@TiO nanoarray: a heterostructured electrocatalyst for high-efficiency nitrate reduction to ammonia.

Electrochemical nitrate (NO) reduction emerges as a promising strategy to maintain the balance of the global nitrogen cycle and an alternative to nitrogen electroreduction for ambient ammonia (NH) synthesis. However, the complicated multiple-electron transfer process of NO-to-NH conversion demands catalysts with high selectivity for NH production. Herein, CoS nanoparticle decorated TiO nanobelt array on a titanium plate (CoS@TiO/TP) is reported as a superb electrocatalyst for the NO reduction reaction.

Visible-Light-Initiated Multicomponent Reactions of α-Diazoesters to Access Organophosphorus Compounds.

A simple visible-light-initiated strategy has been established for the construction of organophosphorus compounds via aerobic multicomponent reaction of α-diazoesters, cyclic ethers, and P(O)H compounds under air. A number of phosphonates and phosphinates could be efficiently isolated in moderate to good yields without the use of photosensitizers and metal reagents. This multicomponent reaction has advantages of mild condition, simple operation, eco-friendly energy, good functional-group tolerance, and gram-scale synthesis.

Cascade amplification strategy combined with analyte-triggered fluorescence switching of dual-quenching system for highly sensitive detection of isoniazide.

A sensitive fluorescence sensing platform consisting of manganese dioxide nanosheets (MnO) and gold nanoparticles (AuNPs) as dual nanoquenchers has been constructed to detect isoniazid combined with analyte-triggered cascade reactions. The fluorescence of 2,3-diaminophenazine (DAP) is quenched simultaneously by MnO and AuNPs via inner filter effect. MnO is decomposed by isoniazid to generate Mn, which makes AuNPs aggregated.

Carbon quantum dots-functionalized silica stationary phase for pharmaceutical analysis by a green liquid chromatography mode.

Facing the trends of green chemistry, this work tries to find a novel material for per aqueous liquid chromatography (PALC) aiming to reduce the consumption of hazardous reagents. As a kind of green nanomaterials, the chromatographic performance of carbon quantum dots (CQDs) in PALC was rarely studied. Here, hydrophilic CQDs were prepared by a simple hydrothermal method using citric acid and ethylenediamine as carbon sources.

A T-rich nucleic acid-enhanced electrochemical platform based on electroactive silver nanoclusters for miRNA detection.

DNA-templated silver nanoclusters (DNA/AgNCs) serve as a useful electrochemical sensing nanomaterial characterized by excellent electroactivity and good stability, while the effect of surrounding nucleotides on their electroactivity has not been studied. Herein, we validated a nucleotide-assisted enhancement mechanism of the DNA/AgNCs electroactivity caused by T-rich nucleic acid sequences in the vicinity of AgNCs. Based on the T-rich nucleic acid-enhanced AgNCs (NAE-AgNCs) combined with hybrid chain reaction (HCR), a novel signal-enhanced electrochemical biosensing platform was established for the ultrasensitive detection of miRNA.

Terbium (III)-based Metallacrowns with aggregation-induced emission feature coupled with cu (II) for fluorescence detection of cysteine.

The Metallacrowns (MCs) composed of repeated [Metal-N-O] subunits are a type of new material, but the MCs have not been developed and utilized in analytical applications. This essay reports on a new kind of terbium(III)-based Metallacrowns (Tb-MCs) with aggregation-induced emission (AIE) feature to build a sensing platform. It is first time that Tb-MCs are able to aggregate to larger aggregates in water along with a bright green emission, so that the property makes it possible to apply in biosensing.

Co-crystallization and structure determination: An effective direction for anti-SARS-CoV-2 drug discovery.

Safer and more-effective drugs are urgently needed to counter infections with the highly pathogenic SARS-CoV-2, cause of the COVID-19 pandemic. Identification of efficient inhibitors to treat and prevent SARS-CoV-2 infection is a predominant focus. Encouragingly, using X-ray crystal structures of therapeutically relevant drug targets (PL, M, RdRp, and S glycoprotein) offers a valuable direction for anti-SARS-CoV-2 drug discovery and lead optimization through direct visualization of interactions.

[Recent advances in chemical derivatization-based chromatography-mass spectrometry methods for analysis of aldehyde biomarkers].

Human exposure to chemical pollutants in the environment can cause a variety of diseases, including cancer, diabetes, cardiovascular disease, and neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, etc.). Exogenous and environmental pollutant exposure-induced endogenous aldehydes are highly reactive electrophilic compounds that can form covalently modified products with a variety of important biological molecules in the human body, thus inducing toxic effects.

MOF@MnOnanocomposites prepared usingmethod and recyclable cholesterol oxidase-inorganic hybrid nanoflowers for cholesterol determination.

In this work, through thegrowth of MnOnanosheets on the surface of terbium metal-organic frameworks (Tb-MOFs), MOF@MnOnanocomposites are prepared and the fluorescence of Tb-MOFs is quenched significantly by MnO. Additionally, the hybrid nanoflowers are self-assembled by cholesterol oxidase (ChOx) and copper phosphate (Cu(PO)·3HO). Then a new strategy for cholesterol determination is developed based on MOF@MnOnanocomposites and hybrid nanoflowers.

pH-modulated aggregation-induced emission of Au/Cu nanoclusters and its application to the determination of urea and dissolved ammonia.

A fluorescence platform is designed based on aggregation-induced emission of Au/Cu nanoclusters (Au/Cu NCs) driven by pH value. When pH increases from 6.0 to 7.

Lead halide perovskites with aggregation-induced emission feature coupled with gold nanoparticles for fluorescence detection of heparin.

Herein, a new kind of lead halide perovskite (LHP, (CHNH)PbI) with aggregation-induced emission (AIE) feature is developed as a fluorescent probe for heparin (Hep). The LHPs exhibit high emission when they aggregate in water. Interestingly, a few picomoles of dispersed gold nanoparticles (AuNPs) can quench the emission of LHPs, but the aggregated AuNPs are invalid.

A ratiometric fluorescence assay for bleomycin based on dual-emissive chameleon DNA-templated silver nanoclusters.

The authors design dual-emissive DNA-templated silver nanoclusters (DNA-AgNCs) for ratiometric fluorescence sensing bleomycin (BLM) for the first time. A hairpin probe containing two different C-rich DNA templates at two terminals is used to synthesize chameleon DNA-AgNCs, which possess two emission peaks when they are in close proximity. A strong emission is founded at 622 nm (λex = 570 nm) while a weak one is located at 572 nm (λex = 504 nm).

A fluorescence strategy for monitoring α-glucosidase activity and screening its inhibitors from Chinese herbal medicines based on Cu nanoclusters with aggregation-induced emission.

Herein, the self-assembly of 1-dodecanethiol-capped Cu nanoclusters (DT-Cu NCs) is obtained by annealing of dibenzyl ether solution of nanoclusters. These aggregates are composed of small clusters and emit a high level of aggregation-induced emission (AIE) in water. Based on the quenching effect of 4-nitrophenol (4-NP) on DT-Cu NCs, a fluorescence strategy is developed to monitor α-glucosidase (α-Glu) activity and screen its inhibitors from Chinese herbal medicines.

Ce-triggered cascade reaction for ratiometric fluorescence detection of alendronate.

A ratiometric fluorescence assay for alendronate (ALDS) has been designed with Ce-triggered cascade chromogenic reaction. This strategy involves three processes: (1) Ce oxidizes ascorbic acid (AA) into dehydroascorbic acid (DHAA), which then condenses with o-phenlenediamine (OPD) to generate fluorescent 3-(dihydroxyethyl)furo[3,4-b] quinoxaline-1-one (DFQ), presenting the maximum emission at 434 nm; (2) As oxidase-mimics, Ce can oxidize OPD into fluorescent 2,3-diaminophenazine (DAP) which shows a strong emission at 568 nm; (3) ALDS inhibits the oxidation ability of Ce towards OPD, thus inhibiting the generation of DAP. Accordingly, a homogeneous ratiometric fluorescence system with dual emission comes into being and the presence of ALDS can change the fluorescence intensity ratio obviously.

12-Plex UHPLC-MS/MS analysis of sarcosine in human urine using integrated principle of multiplex tags chemical isotope labeling and selective imprint enriching.

Urinary sarcosine was considered to be a potential biomarker for prostate cancer (Pca). In this work, an integrated strategy of multiplex tags chemical isotope labeling (MTCIL) combined with magnetic dispersive solid phase extraction (MDSPE), was proposed for specific extraction and high-throughput determination of sarcosine by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). In the past three months, we have developed 8-plex MTCIL reagents with excellent qualitative and quantitative performance.

13-Plex UHPLC-MS/MS Analysis of Hexanal and Heptanal Using Multiplex Tags Chemical Isotope Labeling Technology.

In this work, a new series of chemical isotope labeling reagents, levofloxacin-hydrazide-based mass tags (LHMTs) named as LHMT359/360/361/362/363/364/365/366/373/375/376/378/379/381 were first designed and synthesized for the high-throughput analysis of potential biomarkers containing hexanal and heptanal of lung cancer. We exploited a new core structure of levofloxacin-, which significantly enhanced the multiplexing capability. Among them, LHMT359 was used for labeling standard compounds as internal standards for quantification.

Derivatization-based magnetic dummy molecularly imprinted polymers integrated with 4-plex stable isotope labeling derivatization strategy for specific and rapid determination of L-hydroxyproline in human serum.

The specific determination of L-hydroxyproline (Hyp) can serve as a potential indicator for early clinical diagnosis of liver fibrosis. In this work, an integrated strategy based on 4-plex stable isotope labeling derivatization combined with dummy magnetic molecularly imprinted polymers (QSILD-DMMIPs) was developed for specific extraction and rapid determination of Hyp in human serum by ultra high performance liquid chromatography tandem mass spectrometry. A new series of QSILD reagents d/d/d/d-6-N-methyl-rhodamine 6G-N-hydroxysuccinimidyl formate (d/d/d/d-MRSF) were designed, synthesized and applied for the high-throughput labeling of Hyp in serum samples.

8-Plex stable isotope labeling absolute quantitation strategy combined with dual-targeted recognizing function material for simultaneous separation and determination of glucosylsphingosine and galactosylsphingosine in human plasma.

Glucosylsphingosine (GlcS) in plasma is considered to be a reliable biomarker of Gaucher disease. The detection difficulty of GlcS is that it is difficult to achieve simultaneous separation and quantification with its isomer galactosylsphingosine (GalS), a biomarker of Krabbe disease. In this work, a multiplexed stable isotope labeling absolute quantization strategy coupled with magnetic dispersive solid phase extraction using new prepared dummy magnetic molecularly imprinted polymers (DMMIPs) has been developed for this purpose by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS).

9-Plex ultra high performance liquid chromatography tandem mass spectrometry determination of free hydroxyl polycyclic aromatic hydrocarbons in human plasma and urine.

Hydroxyl-polycyclic aromatic hydrocarbons (OH-PAHs) are biomarkers for assessing the exposure levels of polycyclic aromatic hydrocarbons (PAHs). A series of stable isotope mass tags (SIMT-332/338/346/349/351/354/360/363/374/377) were firstly designed and synthesized to perform multiplexed stable isotope labeling derivatization (MSILD) of OH-PAHs in human plasma and urine. Their derivatives were enriched and purified by magnetic dispersive solid phase extraction (MDSPE) using prepared FeO/GO and then determined by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) in multiple reaction monitoring mode.