Iron Porphyrin-Based Composites for Electrocatalytic Oxygen Reduction Reactions.

The oxygen reduction reaction (ORR) is one of the most critical reactions in energy conversion systems, and it facilitates the efficient conversion of chemical energy into electrical energy, which is necessary for modern technology. Developing efficient and cost-effective catalysts for ORRs is crucial for advancing and effectively applying renewable energy technologies such as fuel cells, metal-air batteries, and electrochemical sensors. In recent years, iron porphyrin-based composites have emerged as ideal catalysts for facilitating effective ORRs due to their unique structural characteristics, abundance, advances in synthesis, and excellent catalytic properties, which mimic natural enzymatic systems.

A Rhodamine-based high-sensitivity low-cytotoxicity probe for rapid turn-on detection of Hg.

By integrating Rhodamine B and 4-phenylmorpholine moieties, a novel fluorescent probe named RhPy is synthesized for detecting Hg. Its recognition mechanism involves the reaction of Hg with dithiooxamide, ultimately triggering the opening of the Rhodamine spirolactam and forming a new molecule RhPy-S with strong emission. The probe exhibits impressive limit of detection (0.

Turn-on fluorescent probe based on dicyanoisophorone for bioimaging and rapid detection of peroxynitrite in aqueous media.

A novel dicyanoisophorone-based colorimetric fluorescent probe 3 has been prepared for recognizing peroxynitrite in aqueous conditions. A large bathochromic shift of the absorption band is observed upon titration with ONOO, inducing a clearly visible solution color change from yellow to pale pink, which makes "naked-eye" detection possible. Moreover, probe 3 can react instantly with ONOO and is accompanied by a significant fluorescence enhancement at 621 nm while the detection limit is as low as 37 nM.

A Dicyanoisophorone-based Fluorescent Turn-on Probe for Rapid Detecting Thiophenol in Aqueous Medium and Living Cell Imaging.

A novel colorimetric and fluorescent thiophenol probe based on dicyanoisophorone has been successfully achieved, which has low-cost, easy operation, high selectivity, sensitivity and stability. The chemosensor shows a large Stokes shift and approximately 170 nm when excited at 510 nm. ISO-DiNO could be utilized as "Turn-on" and a naked-eyes chemosensor to detect PhSH, which is accompanied by a distinct color shift from red to dark purple with strong red fluorescence at 365 nm UV-light.

AIE-active large Stokes-shift BODIPY Functionalized with Carbazolyl for Lysosome-Targeted Imaging in Living Cells.

A large number of studies have shown that lysosomal microcircumstances changes can affect many physiological and pathological processes at the cellular level. However, the visual detection of lysosomal microcircumstances is relatively difficult due to low pH (4.5-6.

Dual detection of Hg and Pb by a coumarin-functionalized Schiff base in environmental and biosystems.

Fluorescent chemosensors are often preferred for tracking toxic ions because of their non-destructive measurement and ease of use in environmental real samples and biosystems. Exploring high selectivity, great sensitivity, and biocompatible fluorophores with facile, accessible and dual-responsive features is currently highly demanding. A coumarin-based naphthol hydrazone Schiff base chemosensor, NaChro, is designed and synthesized in a two-step process to detect toxic metal ions with strong emission.

Discovering a New Drug Against Acute Kidney Injury by Using a Tailored Photoacoustic Imaging Probe.

Acute kidney injury (AKI) has become an increasing concern for patients due to the widespread clinical use of nephrotoxic drugs. Currently, the early diagnosis of AKI is still challenging and the available therapeutic drugs cannot meet the clinical demand. Herein, this work has investigated the key redox couple involved in AKI and develops a tailored photoacoustic (PA) imaging probe (AB-DiOH) which can reversibly respond to hypochlorite (ClO-)/glutathione (GSH) with high specificity and sensitivity.

Strategies for Improving Selectivity and Sensitivity of Schiff Base Fluorescent Chemosensors for Toxic and Heavy Metals.

Toxic cations, including heavy metals, pose significant environmental and health risks, necessitating the development of reliable detection methods. This review investigates the techniques and approaches used to strengthen the sensitivity and selectivity of Schiff base fluorescent chemosensors designed specifically to detect toxic and heavy metal cations. The paper explores a range of strategies, including functional group variations, structural modifications, and the integration of nanomaterials or auxiliary receptors, to amplify the efficiency of these chemosensors.

A pyridine modified naphthol hydrazone Schiff base chemosensor for Al via intramolecular charge transfer process.

A pyridine modified naphthol hydrazone Schiff base chemosensor, NaPy, was prepared in a two-step process to detect aluminum ion (Al) in different samples. The probe shows a turn-off emission response towards Al at a 1:1 binding stoichiometry via intramolecular charge transfer (ICT) mechanism, as validated by density functional theory (DFT) calculations and a series of spectroscopic measurements. The response time is slightly over one minute with a limit of detection (LOD) value of 0.

A BODIPY-based fluorescent chemosensor with 2, 6-substitution for visual and highly selective detection of S.

BODIPY derivatives have often been employed as fluorescent sensors to probe toxic ions in environment and living systems, such as sulfide ion (S). Whilst many structure modifications have been exploited on groups at the 3, 5, 8-positions, there are quite few examples on tailoring the 2,6-substituents for chemosensor investigations. Herein, we design and synthesize a 2,6-substituted BODIPY molecule, LM-BDP, to use as a fluorescent probe for detecting S in aqueous media.

A naphthol hydrazone Schiff base bearing benzothiadiazole unit for fluorescent detection of Fe in PC3 cells.

Naphthol hydrazone derivatives are recognized as efficient chelating agents for both qualitative and quantitative detection of metal ions. Here we design a naphthol hydrazine-based chemosensor with covalently linking a strong electron-withdrawing benzothiadiazole group to modulate the molecular electronic structure, nominated as NtHzBtd. The fluorescent probe performs excellent selectivity and sensitivity towards Fe with 1:1 binding stoichiometry, while exhibiting a quick response at 55 s with a relatively low limit of detection of 0.

Detection of wheat toxigenic Aspergillus flavus based on nano-composite colorimetric sensing technology.

Volatile organic compounds (VOCs) are an important indicator for fungal-infected wheat identification. This work proposes a novel approach for toxigenic Aspergillus flavus infected wheat identification through characteristic VOCs analyzed by nano-composite colorimetric sensors. Nanoparticles of poly styrene-co-acrylic acid (PSA), porous silica nanoparticles (PSN), and metal-organic framework (MOF) were combined with boron dipyrromethene (BODIPY) to fabricate nano-composite colorimetric sensors.

Promotion of Catalytic Oxygen Reduction Reactions: The Utility of Proton Management Substituents on Cobalt Porphyrins.

Three ABAB-type cobalt -tetraarylporphyrins with fluorine (), acetic acid (), and cyanoacetic acid () groups at the -positions of phenyl rings at the 10,20-positions are synthesized and evaluated as catalysts for oxygen reduction reactions (ORRs). In density functional theory calculations, the frontier molecular orbitals of these complexes were found to be stabilized relative to model complexes with electron-withdrawing atoms or moieties on the -aryl rings. Electrochemical measurements suggest that electrodes with ( exhibit the most positive ORR potential values and the highest limiting current density in both acidic and alkali electrolytes, while the electrocatalyst exhibits extremely low ORR performance.

Turn-off detection of Cr(III) with chelation enhanced fluorescence quenching effect by a naphthyl hydrazone Shiff base chemosensor.

A thiophene substituted naphthyl hydrazone derivative NHT was synthesized using a one-step route for the detection of trivalent chromium (Cr). UV-visible absorption and emission spectra, density functional theory calculations as well as H NMR titration confirmed that the probe underwent a turn-off response via the chelation enhanced fluorescence quenching effect upon exposure to Cr and the NHT-Cr complex was formed at a 1:1 binding stoichiometry. NHT exhibited a fast response rate of 2.

A dicyanoisophorone-based fluorescent probe for hypochlorite with a fast response and its applications in bioimaging.

One kind of phenolic substituted dicyanoisophorone derivative (Is-OL) has been designed and successfully synthesized for the detection of hypochlorite in water samples, test strips and living HeLa cells. The probe Is-OL showed high sensitivity and selectivity to hypochlorite over other competitive ROS and metal ions. Moreover, Is-OL can react instantaneously with hypochlorite (<5 s) while exhibiting a significant color change from yellow to colorless, which makes "naked-eye" detection possible with a low detection limit (0.

Near-Infrared Photoacoustic Probe for Reversible Imaging of the ClO/GSH Redox Cycle In Vivo.

Homeostasis of the cellular redox status plays an indispensable role in diverse physiological and pathological processes. Hypochlorite anion (ClO) and glutathione (GSH) represent an important redox couple to reflect the redox status in living cells. The current cellular redox probes that detect either ClO or GSH alone are not accurate enough to monitor the real redox status.

Overview of advanced technologies for volatile organic compounds measurement in food quality and safety.

Food quality and nutrition have received much attention in recent decades, thanks to changes in consumer behavior and gradual increases in food consumption. The demand for high-quality food necessitates stringent quality assurance and process control measures. As a result, appropriate analytical tools are required to assess the quality of food and food products.

A simple quinoline-thiophene Schiff base turn-off chemosensor for Hg detection: spectroscopy, sensing properties and applications.

A new Schiff base probe (QT) consisting of 8-aminoquinoline (Q) and thiophene-2-carboxaldehyde (T) moieties has been synthesized. QT undergoes chelation-enhanced fluorescence quenching when exposed to Hg due to coordination by the sulfur and nitrogen atoms of QT thus forming a facile "turn-off" sensor. The formation of the chelation complex was confirmed by UV-visible absorption and emission spectral measurements, H NMR titration and density functional theory calculations.

Advanced applications of chemo-responsive dyes based odor imaging technology for fast sensing food quality and safety: A review.

Public attention to foodquality and safety has been increased significantly. Therefore, appropriate analytical tools are needed to analyze and sense the food quality and safety. Volatile organic compounds (VOCs) are important indicators for the quality and safety of food products.

Substituents and the induced partial charge effects on cobalt porphyrins catalytic oxygen reduction reactions in acidic medium.

Charge states at the catalytic interface can intensely alter the charge transfer mechanism and thus the oxygen reduction performance. Two symmetric cobalt porphyrins with electron deficient 2,1,3-benzothiadiazole (BTD) and electron-donating propeller-like triphenylamine (TPA) derivatives have been designed firstly, to rationally generate intramolecular partial charges, and secondly, to utilize the more exposed molecular orbitals on TPA for enhancing the charge transfer kinetics. The catalytic performance of the two electrocatalysts was examined for oxygen reduction reactions (ORR) in acidic electrolyte.

Novel broad-spectrum-driven g-CN with oxygen-linked band and porous defect for photodegradation of bisphenol A, 2-mercaptophenthiazole and ciprofloxacin.

Abundant active oxygen free radicals could efficiently remove refractory organic pollutants. In previous research, the original carbon nitride can form more hydrogen peroxide, however, owing to the limitation of its band structure, the original carbon nitride cannot decompose the hydrogen peroxide to generate more active oxygen free radicals. Herein, this work reports a simple bottom-up synthesis method, which synthesize a broad-spectrum-response carbon nitride (CN-CA) with oxygen-linked band and porous defect structure, while adjusting the band structure, and the introduction of the oxygen-linked band structure can also decompose the hydrogen peroxide produced by the original carbon nitride to form more active oxygen free radicals.

Enhanced Oxygen Reduction Reaction Performance Using Intermolecular Forces Coupled with More Exposed Molecular Orbitals of Triphenylamine in Co-porphyrin Electrocatalysts.

Triphenylamine (TPA) has often been used as a building block to construct functional organic materials yet is rarely employed in oxygen reduction reaction (ORR) due to its strong electron-donating ability. This versatile segment bears a three-dimensional spatial structure whose effect has not been fully explored in catalytic systems. To this end, five symmetric cobalt porphyrins with carbazole and TPA derivatives have been synthesized and their ORR performance has been evaluated in acid medium.

A novel colorimetric sensor array based on boron-dipyrromethene dyes for monitoring the storage time of rice.

A novel colorimetric sensor array based on boron-dipyrromethene (BODIPY) dyes was developed to monitor the volatile organic compounds (VOCs) of rice at different storage times. The VOCs of rice at different storage times were analyzed through GC-MS combined with multivariate analysis, and the compound 18-crown-6 was found significantly changed during rice aging process. Aimed at 18-crown-6 with particular macrocyclic structure, a series of BODIPYs were targeted synthesized for the selection of sensitive chemically responsive dyes.