Determination of five alkylhydrazines by isotope-coded derivatization combined with ultra-high-performance liquid chromatography-tandem mass spectrometry.

Alkylhydrazines, extensively used in agricultural and military applications, pose notable environmental and health concerns due to their toxicity and potential accumulation in food chains. A novel isotope-coded derivatization (ICD) method was developed using 4-(N-methylphenanthroimidazolyl)-benzaldehyde as the reagent, enabling precise quantification of five alkylhydrazines in environmental and food matrices using ultra-high-performance liquid chromatographytandem mass spectrometry. The detection limits (0.

Recent advances in molecular-imprinting-based solid-phase microextraction for determination of pharmaceutical residues.

Pharmaceutical residues usually exist in various complicated matrices at trace levels, but pose potential threats to human health and ecological environment. Recognition and determination of the residues are important and urgent. Therefore, efficient sample pretreatment techniques become a research hotspot for the sensitive and precise determination by chromatography and mass spectrometry.

Albumin Modulated Homodimer as an Efficient Photosensitizer for Long-Term Imaging-Guided Tumor Therapy Directed with Sunlight Irradiation.

The reactive oxygen species (ROS) amplification caused by inevitable plasma albumin encapsulation is still a challenge to circumvent the systemic adverse effects in the photodynamic therapy (PDT) process. Herein, a disulfide bond linked homodimer, Cy1280, which is modulated by albumin to accurately balance the fluorescence and ROS generation and exhibit a weak fluorescence and sealed PDT effect during blood circulation, is exploited. Cy1280 can be specifically internalized and dispersed at the tumor site via Organic Anion Transporter Proteins (OATPs) and thiol-disulfide exchange mediated synergistic uptake and activated after mild sunlight irradiation (100 ± 5 Klx) to sensitize neighboring oxygen in cellular mitochondria to execute direct protein dysfunction effect.

Evaluation of multilayer co-extrusion film and other three plastic membranes as passive samplers for determination of polyhalogenated carbazoles in water.

Passive sampling methods can provide valuable insights for monitoring hydrophobic organic compounds (HOCs) in aquatic environments. As the list of target HOCs expands, there is an increasing demand for passive samplers that can detect a broader range of these compounds. This study aimed to assess the efficacy of a three-layer co-extruded polyethylene/ethylene vinyl acetate (TLC-EVA) film alongside three existing materials (polyethylene (PE), polydimethylsiloxane (PDMS), and poly(methyl methacrylate) (PMMA)) for passive sampling of carbazole and five halogenated carbazoles (PHCZs), a group of dioxin-like chemicals, in water.

A Novel High-Conjugated Probe of 4-(Acridone-10-yl)-Phenylethyl Chloroformate (APE-Cl) for Rapid Detection of Amino Compounds Using HPLC with Fluorescence Detection.

The fluorescence detection of amino compounds and the evaluation of their content in environmental samples are vital, not only for assessing food quality but also for studying soil organic matter. Here, we present the synthesis and application of a novel fluorescent probe, 4-(9-acridone)benzylmethyl carbonochloride (APE-Cl), for detecting amino compounds via a chloroformate reaction with fluorescence detection. The complete derivatization reaction of APE-Cl with amino compounds can be accomplished in aqueous acetonitrile within 5 min at room temperature, using 0.

Molecularly Imprinted Ratiometric Fluorescent Sensors for Analysis of Pharmaceuticals and Biomarkers.

Currently, analyzing pharmaceuticals and biomarkers is crucial for ensuring medication safety and protecting life and health, and there is an urgent need to develop new and efficient analytical techniques in view of the limitations of traditional analytical methods. Molecularly imprinted ratiometric fluorescent (MI-RFL) sensors have received increasing attention in the field of analytical detection due to their high selectivity, sensitivity and anti-interference ability, short response time, and visualization. This review summarizes the recent advances of MI-RFL sensors in the field of pharmaceuticals and biomarkers detection.

Visible-Light Photoredox-Catalyzed Difunctionalization of Alkynes with Quinoxalin-2(1)-Ones, PS, and Alcohols.

Visible-light photoredox-catalyzed method has been developed for the synthesis of quinoxalin-2(1)-one-containing vinyl phosphorodithioates via direct difunctionalization of alkynes with quinoxalin-2(1)-ones, PS and alcohols. This four-component reaction could be carried out under metal-free and mild conditions, affording a number of quinoxalin-2(1)-one-containing vinyl phosphorodithioates in moderate to good yields with Z-isomers as the major products. Photocatalytic radical mechanism is proposed based on the results of radical trapping and fluorescence quenching experiments.

Inflammatory bowel disease alters in vivo distribution of orally administrated nanoparticles: Revealing via SERS tag labeling technique.

Nanoparticles (NPs) could be uptake orally and exposed to digestive tract through various sources such as particulate pollutant, nanomedicine and food additive. Inflammatory bowel disease (IBD), as a global disease, induced disruption of the intestinal mucosal barrier and thus altered in vivo distribution of NPs as a possible consequence. However, related information was relatively scarce.

Determination of genotoxic impurities of aromatic aldehydes in pharmaceutical preparations by high performance liquid chromatography after derivatization with N-Cyclohexyl-4-hydrazino-1,8-naphthalenediimide.

The detection of aromatic aldehydes, considered potential genotoxic impurities, holds significant importance during drug development and production. Current analytical methods necessitate complex pre-treatment processes and exhibit insufficient specificity and sensitivity. This study presents the utilization of naphthalenediimide as a pre-column derivatisation reagent to detect aromatic aldehyde impurities in pharmaceuticals via high-performance liquid chromatography (HPLC).

NIR Light-Activated Mitochondrial RNA Cross-Linking Strategy for HS Monitoring and Prolonged Colorectal Tumor Imaging.

Molecular diffusion and leakage impede the long-term retention of probes/drugs and may cause potential adverse effects in theranostic fields. Spatiotemporally manipulating the organelle-immobilization behavior of probes/drugs for prolonged tumor retention is indispensable to achieving effective cancer diagnosis and therapy. Herein, we propose a rational strategy that could realize near-infrared light-activated ribonucleic acids (RNAs) cross-linking for prolonged tumor retention and simultaneously endogenous hydrogen sulfide (HS) monitoring in colorectal tumors.

Development of fluorescent probes with specific recognition moiety for hydrogen polysulfide.

Hydrogen polysulfide (HS, n > 1) is an important component of reactive sulfur species (RSS), which is an important substance for maintaining the redox balance in cells. However, limited recognition moieties are available for hydrogen polysulfide probe design. In this study, we have constructed a small library containing several organic molecules to explore a new specific recognition moiety for HS fluorescent probe design.

Sunlight-directed fluorophore-switch in photosynthesis of cyanine subcellular organelle markers for bio-imaging.

The photoconvertible fluorophore synthesis enables the light controlled imaging channels switch for accurate tracking the quantity and localization of intracellular biomolecules in chemical biology. Herein, we repurposed the photochemistry of Fischer's base and developed a sunlight-directed fluorophore-switch strategy for high-efficiency trimethine cyanine (Cy3.5/Cy3) synthesis.

Rapid Analysis of Estrogens in Meat Samples by High Performance Liquid Chromatography with Fluorescence Detection.

A novel reagent named 4-(N-methyl-1,3-dioxo-benzoisoquinolin-6-yl-oxy)benzene sulfonyl chloride (MBIOBS-Cl) for the determination of estrogens in food samples by high-performance liquid chromatography (HPLC) with fluorescence detection has been developed. Estrogens could be easily labeled by MBIOBS-Cl in NaCO-NaHCO buffer solution at pH 10.0.

Polarity-Ultrasensitive and Lipophilicity-Enhanced Structurally Modified Hemicyanine for Two-Color Staining to Reveal Cell Apoptosis during Chemotherapy.

Programmed cell death (PCD) is a precisely controlled physiological process to sustain tissue homeostasis. Even though the PCD pathways have been explicitly subdivided, the individual cell death process seems to synergistically operate to eliminate cells rather than separately execute signal transduction. Apoptosis is the dominant intracellular PCD subtype, which is intimately regulated and controlled by mitochondria, thus tracing mitochondrial actions could reveal the dynamic changes of apoptosis, which may provide important tools for screening preclinical therapeutic agents.

A FRET-based ratiometric fluorescent probe for Hg detection in aqueous solution and bioimaging in multiple samples.

Mercury ion, as a metal cation with great toxic effect, is widely present in various production and living environments. It seriously threatens human health and environmental safety. It is of great significance to develop convenient and effective methods for mercury ion detection.

Colorimetric detection of heavy metal ions with various chromogenic materials: Strategies and applications.

Detection of heavy metal ions has drawn significant attention in environmental and food area due to their threats to the human health and ecosystem. Colorimetry is one of the most frequently-used methods for the detection of heavy metal ions owing to its simplicity, easy operation and rapid on-site detection. The development of chromogenic materials and their sensing mechanisms are the key research direction in the area of colorimetric method.

Homocysteine-specific fluorescence detection and quantification for evaluating -adenosylhomocysteine hydrolase activity.

Studies have shown that homocysteine (Hcy) levels are closely related to cardiovascular and cerebrovascular diseases. In this work, we have developed and synthesized three copper complexes, F542-Cu2+, F508-Cu2+, and F465-Cu2+ for Hcy detection. The different binding constants () of the copper complexes endow them with dramatic reactivity toward biothiols.

SERS based Y-shaped aptasensor for early diagnosis of acute kidney injury.

Considering the pivotal role of biomarkers in plasma, the development of biomarker specific sensing platforms is of great significance to achieve accurate diagnosis and monitor the occurrence and progress in acute kidney injury (AKI). In this paper, we develop a promising surface-enhanced Raman scattering-based aptasensor for duplex detection of two protein biomarkers in AKI. Exploiting the base-pairing specificity of nucleic acids to form a Y-shaped self-assembled aptasensor, the MGITC labelled gold nanoparticles will be attached to the surface of magnetic beads.

Electrocatalytic two-electron oxygen reduction over nitrogen doped hollow carbon nanospheres.

The two-electron oxygen reduction reaction (2e ORR) has become a hopeful alternative for production of hydrogen peroxide (HO), but its practical feasibility is hindered by the lack of efficient electrocatalysts to achieve high activity and selectivity. Herein, we successfully synthesized outstanding nitrogen doped hollow carbon nanospheres (NHCSs) for electrochemical production of HO. In 0.

Rational Construction of Fluorescence Turn-Off Fluorinated Carbon Fiber/Ag Composites and Their Anticancer and Antibacterial Activities.

Although fluorinated carbon fiber/Ag composites possess unique structure and special charge distribution and exhibit great potential in numerous fields, their synthesis has long been a headache because of inert chemistry bonds, low surface energy, and easy aggregation. Herein, we first demonstrate a fresh concept of constructing the nanoscale hydrosoluble fluorinated carbon fiber oxide (FCO)/Ag composite and then integrate it as a highly effective targeting nanocarrier and photothermal therapy and antibacterial agent. Chemical introduction of oxygen allows us to controllably deposit Ag nanoparticles (AgNPs) for the first time and further facilitates surface modification with folic acid prelinked bovine serum albumin to induce targeted endocytosis toward tumor cells.

Novel Porous Rhodium Metal-Organic Aerogel for Efficient Removal of Organic Dyes and Catalysis of Si-H Insertion Reactions.

Metal-organic gels (MOGs) are attracting increasing attention for removal of organic dyes from aqueous solution and for catalysis of Si-H insertion reactions. Herein, we report that a reaction of porphyrin derivative with Rh(OAc) generates stable metal-organic gels and subsequent subcritical carbon dioxide drying affords metal-organic aerogels. Owing to their micro- and mesoporosity, the aerogels adsorbed dyes.

Cerium Ammonium Nitrate-Mediated Access to Biaryl Lactones: Substrate Scopes and Mechanism Studies.

Herein we described an access to biaryl lactones from -aryl benzoic acids via intramolecular O-H/C-H oxidative coupling with the commonly used cerium ammonium nitrate (CAN) as the one-electron oxidant under a thermal condition. The radical interrupting experiment suggested a radical process, while the kinetic isotope effect (KIE) showed that the C-H cleavage likely was not involved in the rate-determining step. Competitive reactions, especially the strikingly different ρ values of Hammett equations, indicated that the reaction rate was more sensitive to the electronic properties on the aryl moiety rather than the carboxylic moiety, which corresponded to the first single electron transfer (SET) step.

Evaluation of cyclooxygenase-2 fluctuation via a near-infrared fluorescent probe in idiopathic pulmonary fibrosis cell and mice models.

Idiopathic pulmonary fibrosis (IPF) is a devastating and fatal interstitial lung disease due to various challenges in diagnosis and treatment. Due to its complicated pathogenesis and difficulty in early diagnosis, there is no effective cure. Cyclooxygenase-2 (COX-2) is inextricably associated with pulmonary fibrosis.

Construction of a near-infrared fluorescent probe for ratiometric imaging of peroxynitrite during tumor progression.

Malignant tumors are one of the main causes for human death and are tightly associated with overexpression of reactive oxygen species (ROS) in pathological processes. Therefore, in vivo monitoring of ROS, especially ONOO-, remains of great significance for diagnosis and therapy of tumors to improve the survival rate. Herein, we designed and constructed a reliable near-infrared (NIR) ratiometric fluorescent biosensor CDMS for monitoring the fluctuations of ONOO- in the process of tumor progression.

Catalyst-Free and Transition-Metal-Free Approach to 1,2-Diketones via Aerobic Alkyne Oxidation.

A catalyst-free and transition-metal-free method for the synthesis of 1,2-diketones from aerobic alkyne oxidation was reported. The oxidation of various internal alkynes, especially more challenging aryl-alkyl acetylenes, proceeded smoothly with inexpensive, easily handled, and commercially available potassium persulfate and an ambient air balloon, achieving the corresponding 1,2-diketones with up to 85% yields. Meanwhile, mechanistic studies indicated a radical process, and the two oxygen atoms in the 1,2-diketons were most likely from persulfate salts and molecular oxygen, respectively, rather than water.