Biocompatible Ionic Liquid Based on Curcumin as Fluorescence Probe for Detecting Benzoyl Peroxide without the Interference of H2O2

A high-fidelity dual-channel fluorescence probe for benzoyl peroxide detection and toxicity early warning in food, zebrafish, and mice

Benzoyl peroxide (BPO), as a widely used organic peroxide, has attracted widespread attention from all sectors of society for its environmental hazards and potential risks to human health. Herein, we employed a Förster resonance energy transfer (FRET) strategy to construct a novel ratiometric fluorescent probe CY-DCI for BPO detection in food, zebrafish, and mice. Specifically, a hemicyanine fluorophore and a dicyanoisophorone fluorophore were connected with a piperazine group as donor and acceptor, respectively, and an olefinic unsaturated bond as the reaction site. CY-DCI has favorable selectivity and an excellent detection limit as low as 58.1 nM, and the recovery rates for real-sample detection ranged from 95.8 % to 104 %, with relative standard deviations (RSD) less than 2.58 %. To further improve its practicality, silica gel plates and test strips containing CY-DCI (0-50 μM) were developed for naked-eye detection of BPO with satisfactory results. Additionally, this novel probe was then applied for ratiometric imaging of living zebrafish and mice and showed high ratiometric imaging resolution in the green and red channels, thus demonstrating its practical application for BPO detection and toxicity early warning in food and biosystems.

Ionic Polyimine-Based Composite Membrane with Inductive and Complexation Synergistic Effects for Sensitive and On-Site Fluorescent Detection of Volatile Iodine

Along with the development of nuclear power, concerns about radioactive emissions and the potential for nuclear leakage have been widely raised, particularly of harmful iodine isotopes. However, as a significant component of nuclear air waste, the enrichment and detection of air-dispersed gaseous iodine remain a challenge. In this work, it is focused on developing an attraction-immobilization-detection strategy-based fluorescence method for the on-site detection of volatile iodine, by employing a photoluminescent ionic polyimine network-polyvinylpyrrolidone (IPIN-PVP) composite membrane. This strategy synergizes ion-induced dipole interactions from IPIN and complexation effects from PVP, allowing effective iodine enrichment and immobilization. As a result, the optimized IPIN-PVP membrane exhibits rapid response times of 5 s and a low detection limit of 4.087 × 10-8 m for gaseous iodine. It also introduces a portable handheld detection device that utilizes the composite membrane, offering a practical solution for real-time on-site detection of volatile iodine. This innovation enhances nuclear safety measures and disaster management by providing rapid and reliable iodine detection capabilities.

Bio-based ionic liquid filter with enhanced electrostatic attraction for outside filtration and inside collection of viral aerosols

Hazardous biological pathogens in the air pose a significant public environmental health concern as infected individuals emit virus-laden aerosols (VLAs) during routine respiratory activities. Mask-wearing is a key preventive measure, but conventional filtration methods face challenges, particularly in high humidity conditions, where electrostatic charge decline increases the risk of infection. This study introduces a bio-based air filter comprising glycine ionic liquids (GILs) and malleable polymer composite (GILP) with high polarity and functional group density, which are wrapped around a melamine-formaldehyde (MF) resin skeleton, forming a conductive, porous GIL functionized ionic network air filter (GILP@MF). When subjected to low voltage, the GILP@MF composite efficiently captures VLAs including nanoscale virus particles through the enhanced electrostatic attraction, especially in facing high humidity bioaerosols exhaled by human body. The filtration/collection efficiency and quality factor can reach 98.3% and 0.264 Pa-1 at 0.1 m s-1, respectively. This innovative filter provides effective VLA protection and offers potential for non-invasive respiratory virus sampling, advancing medical diagnosis efforts.

An intelligent smartphone-test strip detection platform for rapid and on-site sensing of benzoyl peroxide in flour samples

Benzoyl peroxide (BPO) is a commonly used flour whitener, but its excessive usage can have adverse effects on human health, such as nutrient loss, vitamin deficiencies and certain diseases. In this study, a europium metal organic framework (Eu-MOF) fluorescence probe was prepared, which exhibited a strong fluorescence emission at 614 nm upon excitation at 320 nm, with a high quantum yield of 8.11%. The red fluorescence of the probe could be effectively quenched by BPO through the inner filter effect (IFE) and photoinduced electron transfer (PET) mechanism. The detection process offered several advantages, including a wide linear range of 0-0.95 mM, a low detection limit of 66 nM and a fast fluorescence response of 2 min. Furthermore, an intelligent detection platform was designed to enhance the practical application of the detection method. This platform combined the portability and visuality of a traditional test strip with the color recognition capability of a smartphone, allowing for the visualization and quantitative detection of BPO in a convenient and user-friendly manner. The detection platform was successfully applied to the analysis of BPO in real flour samples with satisfactory recoveries (99.79%-103.94%), suggesting a promising strategy for the rapid and on-site detection of BPO in food samples.

Real-time monitoring of mercury(II) in water and food samples using a quinoline-based ionic probe

Herein, a novel ionic fluorescent probe for mercury(II) detection is presented consisting of a functional quinoline-based IL. Interestingly, the probe displayed high sensitivity (0.8 nM) and selectivity through the regulation function of electrostatic attraction, where its performance was significantly superior to that of quinoline probes without negative charge. Furthermore, the probe was found to exhibit two different fluorescent signals and colorimetric signals in the presence of different concentrations of mercury(II), which was consistent with the reaction mechanisms of the generation of large conjugated systems and the formation of anion-mercury(II) complexes. Moreover, this probe could be further loaded on a simple filter paper to serve as a visual paper sensor due to its adequate response time of less than 5 s. This regulation function strategy of electrostatic attraction has excellent potential for use in the precise detection of targeted analytes in real complex samples with improved accuracy and selectivity.

Fluorescent and Colorimetric Ionic Probe Based on Fluorescein for the Rapid and On-Site Detection of Paraquat in Vegetables and the Environment

Detection of pesticide paraquat (PQ) is of considerable significance to ensure food safety, and its rapid and on-site detection is still a challenge. Aimed at the ion characteristics of PQ, an "enrichment and detection" strategy was proposed to improve the sensitivity through electrostatic attractions, and the ion characteristic of probes was adopted to increase the portability through avoiding aggregation-caused quenching effects in the paper strips. Herein, a novel anion-functionalized ionic liquid (IL) probe with a large conjugated plane and rich π-electrons ([Fluo][P₆₆₆₁₄]₂) was designed as a fluorescent and colorimetric dual-channel probe to sensitively and rapidly detect trace amounts of PQ in vegetables and the environment. The proposed probe exhibited good linearity with a detection limit of 64.0 nM in the PQ concentration range of 0.3-7.0 μM (fluorometry) and 0.1 μM in that of 0.1-8.0 μM (colorimetry), respectively. In addition, it displayed a rapid fluorescence quenching response from green to dark (<5 s) and excellent anti-interference (among 23 other pesticides) due to dual effects of electrostatic attraction and π-π stacking. Most importantly, the lipophilic IL probe could be applied in real vegetables and environmental samples with a satisfying recovery rate of 98-103% and assembled into a handy paper strip that achieved the visual semiquantitative detection of PQ. This ionic probe provides a feasible approach for rapidly and conveniently detecting PQ for ensuring agricultural and food safety and opens a new avenue to detect ion-responsive analytes in real complex samples by an "enrichment and detection" strategy.

Hydrogen-bonding and "π-π" interaction promoted solution-processable mixed matrix membranes for aromatic amines detection

Detection of hazardous compounds can alleviate risk to human health. However, it remains a challenge to develop easy-to-use testing tools for carcinogenic aromatic amines. Herein, we presented a conjugated molecule-based aniline detector, mixed matrix membranes (MMMs), through the solution-processable strategy. The pentacene-based dispersed phase is achieved using the state-of-the-art ionic liquids (ILs) as the continuous phase, based on which MMMs are easily manufactured by a solution process. Moreover, molecular dynamics (MD) simulations and quantum mechanical calculations suggested that hydrogen bonding and π-π interaction between ILs cations and pentacene could promote the dissolution. These prepared MMMs can offer easy-operation and on-site detection of carcinogenic primary aromatic amines with eye-readable fluorescence signal. This work provides a paradigm for the design of a portable testing device for various hazardous compounds.

Ultralow-cost portable device for cesium detection via perovskite fluorescence

Public anxiety and concern from cesium pollution in oceans have been back on the agenda since tons of nuclear waste water were announced to be poured into oceans. Cesium ion can easily enter organisms and bioaccumulate in animals and plants, thus its harm is chronic to humans through food chains. Here we showed a kind of hybrid ionic liquid membrane (HILM) for detection of cesium ion in seawater through CsPbBr₃ perovskite fluorescence. With sustainability in mind, HILM was built frugally. The lowest cost of HILM is below 3 cents per piece. The HILM can detect cesium ion quickly with eye-readable fluorescence signal. Ultracheap, portable, easy-to-use on-site detection device could offer benefit for personal security and applications in environment science and ecology in the future decades.

Engineering Oxygen-Irrelevant Radical Nanogenerator for Hypoxia-Independent Magnetothermodynamic Tumor Nanotherapy

Tumor hypoxia substantially lowers the treatment efficacy of oxygen-relevant therapeutic modalities because the production of reactive oxygen species in oxygen-relevant anticancer modalities is highly dependent on oxygen level in tumor tissues. Here a distinctive magnetothermodynamic anticancer strategy is developed that takes the advantage of oxygen-irrelevant free radicals produced from magnetothermal decomposable initiators for inducing cancer-cell apoptosis in vitro and tumor suppression in vivo. Free-radical nanogenerator is constructed through in situ engineering of a mesoporous silica coating on the surface of superparamagnetic Mn and Co-doped nanoparticles (MnFe₂ O₄ @CoFe₂ O₄ , denoted as Mag) toward multifunctionality, where mesoporous structure provides reservoirs for efficient loading of initiators and the Mag core serves as in situ heat source under alternating magnetic field (AMF) actuation. Upon exposure to an exogenous AMF, the magnetic hyperthermia effect of superparamagnetic core lead to the rapid decomposition of the loaded/delivered initiators (AIPH) to produce oxygen-irrelevant free radicals. Both the magnetothermal effect and generation of toxic free radicals under AMF actuation are synergistically effective in promoting cancer-cell death and tumor suppression in the hypoxic tumor microenvironment. The prominent therapeutic efficacy of this radical nanogenerator represents an intriguing paradigm of oxygen-irrelevant nanoplatform for AMF-initiated synergistic cancer treatment.

Anomalous Melting Point of Multicharge Ionic Liquids: Structural, Electrostatic, and Orbital Properties of [Ln(NO3)6]3- (Ln = Ce, Pr) Anions

Salts composed of multicharged cations/anions usually exhibit a large lattice energy and strong Coulomb force, which results in high melting points. However, an increasing number of highly charged ionic liquids exceed expectations based on conventional experience; even their melting points are much lower than those found for simple ionic liquids composed of monovalent ions. To further study this phenomenon, we studied a group of stable ionic liquids containing tricharged [Ce(NO₃)₆]^3- and [Pr(NO₃)₆]^3- anions. The structures for [C₆mim]₃[Ce(NO₃)₆] and [C₆mim]₃[Pr(NO₃)₆] were determined by single-crystal X-ray diffraction with triclinic and P1̅ space groups. The electrostatic potential density per unit ion surface and volume was proposed and calculated. Additionally, theoretical analysis based on Hirshfeld surface and charge decomposition was carried out to explore the intermolecular interaction and electronic structure of the lanthanide anions. The electrostatic and orbital properties were found to be more useful for understanding the melting points of highly charged salts compared with the sole use of lattice energy. The electrostatic potential density per unit ion surface and volume showed a linear relationship with the melting point of ionic liquids composed of monovalent to trivalent ions. These structure-melting point relationships will be beneficial for expounding new low-melting-point ionic liquids with a wide liquidus range.

Handy fluorescent paper device based on a curcumin derivative for ultrafast detection of peroxide-based explosives

A useful and inexpensive fluorescent paper-based device was fabricated for ultrafast sensing of peroxide-based explosives.