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Fangqing Wang,1,* Nianlu Li,2,* Wenbo Wang,1 Long Ma,3 Yaru Sun,4 Hong Wang,1 Jinhua Zhan,5 Dexin Yu1 1Department of Radiology, Qilu Hospital, Shandong University, Affiliated Hospital of Shandong University, Jinan, 250012, People’s Republic of China; 2Physical and Chemical Laboratory, Shandong Academy of Occupational Health and Occupational Medicine, Affiliated Hospital of Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, 250002, People’s Republic of China; 3The Testing Center of Shandong Bureau of China Metallurgical Geology Bureau, Shandong Normal University, Jinan, 250014, People’s Republic of China; 4Department of Nuclear Medicine, The Second Hospital of Shandong University, Affiliated Hospital of Shandong University, Jinan, 250033, People’s Republic of China; 5School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jinhua Zhan, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People’s Republic of China, Email jhzhan@sdu.edu.cn Dexin Yu, Department of Radiology, Qilu Hospital, Shandong University, Affiliated Hospital of Shandong University, Jinan, 250012, People’s Republic of China, Tel +86-18560081629, Fax +86-531-86927544, Email yudexin0330@sina.comPurpose: Owing to lack of specific molecular targets, the current clinical therapeutic strategy for triple negative breast cancer (TNBC) is still limited. In recent years, some nanosystems for malignancy treatment have received considerable attention. In this study, we prepared caramelized nanospheres (CNSs) loaded with doxorubicin (DOX) and Fe3O4 to achieve the synergistic effect of combined therapy and real-time magnetic resonance imaging (MRI) monitoring, so as to improve the diagnosis and therapeutic effect of TNBC.Methods: CNSs with biocompatibility and unique optical properties were prepared by hydrothermal method, DOX and Fe3O4 were loaded on it to obtain Fe3O4/DOX@CNSs nanosystem. Characteristics including morphology, hydrodynamic size, zeta potentials and magnetic properties of Fe3O4/DOX@CNSs were evaluated. The DOX release was evaluated by different pH/near-infrared (NIR) light energy. Biosafety, pharmacokinetics, MRI and therapeutic treatment of Fe3O4@CNSs, DOX and Fe3O4/DOX@CNSs were examined in vitro or in vivo.Results: Fe3O4/DOX@CNSs has an average particle size of 160 nm and a zeta potential of 27.5mV, it demonstrated that Fe3O4/DOX@CNSs is a stable and homogeneous dispersed system. The hemolysis experiment of Fe3O4/DOX@CNSs proved that it can be used in vivo. Fe3O4/DOX@CNSs displayed high photothermal conversion efficiency, extensive pH/heat-induced DOX release. 70.3% DOX release is observed under the 808 nm laser in the pH = 5 PBS solution, obviously higher than pH = 5 (50.9%) and pH = 7.4 (less than 10%). Pharmacokinetic experiments indicated the t1/2β, and AUC0–t of Fe3O4/DOX@CNSs were 1.96 and 1.31 -fold higher than those of DOX solution, respectively. Additionally, Fe3O4/DOX@CNSs with NIR had the greatest tumor suppression in vitro and in vivo. Moreover, this nanosystem demonstrated distinct contrast enhancement on T2 MRI to achieve real-time imaging monitoring during treatment.Conclusion: Fe3O4/DOX@CNSs is a highly biocompatible, double-triggering and improved DOX bioavailability nanosystem that combines chemo-PTT and real-time MRI monitoring to achieve integration of diagnosis and treatment of TNBC.Keywords: caramelized nanotheranostic system, combining chemo-photothermal therapy, magnetic resonance imaging monitoring, double-triggering, triple negative breast cancer

Rh single-atom nanozymes are designed to mimic the active sites of ascorbate peroxidase, based on which electrochemical sensors have been developed for efficient ascorbic acid detection.

Nanoplastics are emerging pollutants that pose potential threats to the environment and organisms. However, in-depth research on nanoplastics has been hindered by the absence of feasible and reliable analytical methods, particularly for trace nanoplastics. Herein, we propose a hyphenated method involving membrane filtration and surface-enhanced Raman spectroscopy (SERS) to analyze trace nanoplastics in water. In this method, a bifunctional Ag nanowire membrane was employed to enrich nanoplastics and enhance their Raman spectra in situ, which omitted sample transfer and avoided losing smaller nanoplastics. Good retention rates (86.7% for 50 nm and approximately 95.0% for 100-1000 nm) and high sensitivity (down to 10

Pancreatic adenocarcinoma (PDAC) is one of the deadliest cancers, and it is resistant to most conventional antineoplastic therapies. To address this challenge, gemcitabine (Gem)-loaded carbonaceous nanoparticles (MFC-Gem) as nanozymes and a theranostic platform were fabricated and used for MR-guided ferroptosis-chemo synergetic therapy of PDAC. As a biocompatible carrier, MFC-Gem nanoparticles are regarded as peroxidase-like and glutathione peroxidase-like nanozymes that promote ferroptosis therapy by effectively generating ROS and consuming GSH. Meanwhile, the combination of MnFe

A filtration-based SERS platform was proposed to separate and analyse AgNPs in antibacterial products.

Electrochemiluminescence (ECL) represents a widely explored technique to generate light, in which the emission intensity relies critically on the charge-transfer reactions between electrogenerated radicals. Two types of charge-transfer mechanisms have been postulated for ECL generation, but the manipulation and effective probing of these routes remain a fundamental challenge. Here, we demonstrate the design of quantum dot (QD) aerogels as novel ECL luminophores via a versatile water-induced gelation strategy. The strong electronic coupling between adjacent QDs enables efficient charge transport within the aerogel network, leading to the generation of highly efficient ECL based on the selectively improved interparticle charge-transfer route. This mechanism is further verified by designing CdSe-CdTe mixed QD aerogels, where the two mechanistic routes are clearly decoupled for ECL generation. We anticipate our work will advance the fundamental understanding of ECL and prove useful for designing next-generation QD-based devices.

Surface Lewis acid-base sites in crystal structure may influence the physicochemical properties and the catalytic performances in nanozymes. Understanding the synergistic effect mechanism of Co3O4 nanozymes towards substances (3,3′,5,5′-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2)) induced by surface Lewis acid-base sites is important to enhance the efficiency for peroxidase-like reaction. Herein, ultrathin porous Co3O4 nanosheets with abundant Lewis acid-base sites were prepared by sodium borohydride (NaBH4) reduction treatment, which exhibited high-efficiency peroxidase-like activity compared with original Co3O4 nanosheets. The Lewis acid-base sites for ultrathin porous Co3O4 nanosheets nanozyme were owing to the coordination unsaturation of Co ions and the formation of defect structure. Ultrathin porous Co3O4 nanosheets had 18.26-fold higher catalytic efficiency (1.27 × 10−2 s−1·mM−1) than that of original Co3O4 (6.95 × 10−4 s−1·mM−1) in oxidizing TMB substrate. The synergistic effect of surface acid and base sites can enhance the interfacial electron transfer process of Co3O4 nanosheets, which can be a favor of absorption substrates and the generation of reactive intermediates such as radicals. Furthermore, the limit of detection of hydroquinol was 0.58 µM for ultrathin porous Co3O4 nanosheets, 965-fold lower than original Co3O4 (560 µM). Besides, the linear range of ultrathin porous Co3O4 nanosheets was widely with the concentration of 5.0–1,000 µM. Colorimetric detection of hydroquinol by agarose-based hydrogel membrane was provided based on excellent peroxidase-like properties. This study provided insights into designing high-performance nanozymes for peroxidase-like catalysis via a strategy of solid surface acid-base sites engineering.

The core of the surface-enhanced Raman spectroscopy (SERS)-based techniques for dynamic monitoring is to realize rapid and reversible adsorption. Herein, the integration technology of electro-enhanced adsorption, solid-phase microextraction, and surface-enhanced Raman spectroscopy (EE-SPME-SERS) was developed to obtain sensitive, ultrafast, and reversible SERS response toward in situ monitoring of pharmaceuticals and personal care products (PPCPs). In the EE-SPME-SERS method, a roughened Ag fiber with Au modification (r-Ag/Au fiber) was used as the SERS substrate, SPME sorbent, and working electrode. The r-Ag/Au fiber displayed good SERS sensitivity, ultrahigh photostability, and adsorption properties. The adsorption efficiency of benzidine was 76 times accelerated in EE-SPME-SERS compared to that in static adsorption. The whole process of "sampling and detection" in EE-SPME-SERS can be finished within 1 s. Reversible adsorption and desorption can be achieved in situ by switching the direction of electric field, and the regeneration process takes only a few minutes. Simulated release of benzidine from household wastewater was in situ and dynamically monitored using this strategy. EE-SPME-SERS was proved universal for ionized PPCPs and can detect multicomponents simultaneously. In addition, EE-SPME-SERS showed very good analytical properties. Great potential of EE-SPME-SERS can be expected in environmental monitoring.

Arsenic speciation analysis is important for pollution and health risk assessment. Surface-enhanced Raman Spectroscopy (SERS) is supposed to be a promising detection technology for arsenic species owing to the unique fingerprints. However, further application of SERS is hampered by its poor repeatability. Herein, the role of surface silver ions on colloidal Ag was revealed in SERS analysis of arsenic species. Arsenic species were adsorbed on Ag nanoparticles (Ag NPs) driven by surface silver ions and were simultaneously sensed by the SERS "hot spots" generated from the aggregation of Ag NPs. So, the inconsistent SERS activities of Ag NPs synthesized from different batches can be significantly improved by modifying external silver ions onto Ag NPs (AgNPs@Ag

Surface-enhanced Raman spectroscopy (SERS) of semiconducting TiO2 was used for studying binding modes and surface reactions of molecules bound at the interface but is generally limited by low signa...

Nanoparticle structural parameters, such as size, surface chemistry, and shape, are well-recognized parameters that affect biological activities of nanoparticles. However, whether the core material of a nanoparticle also plays a role remains unknown. To answer this long-standing question, we synthesized and investigated a comprehensive library of 36 nanoparticles with all combinations of three types of core materials (Au, Pt, and Pd), two sizes (6 and 26 nm), and each conjugated with one of six surface ligands of different hydrophobicity. Using this systematic approach, we were able to identify cellular perturbation specifically attributed to core, size, or surface ligand. We discovered that core materials exhibited a comparable regulatory ability as surface ligand on cellular ROS generation and cytotoxicity. Pt nanoparticles were much more hydrophilic and showed much less cell uptake compared to Au and Pd nanoparticles with identical size, shape, and surface ligands. Furthermore, diverse core materials also regulated levels of cellular redox activities, resulting in different cytotoxicity. Specifically, Pd nanoparticles significantly reduced cellular H2O2 and promoted cell survival, while Au nanoparticles with identical size, shape, and surface ligand induced higher cellular oxidative stress and cytotoxicity. Our results demonstrate that nanoparticle core material is as important as other structural parameters in nanoparticle-cell interactions, making it also a necessary consideration when designing nanomedicines.

The functionalization of Ti17 O24 (Oi C3 H7 )20 (Ti17 ) with substituted catechols is studied by using crystallography, Raman spectroscopy, and stopped-flow kinetics. The knowledges on the number of accessible functionalities, their exact location correlated with their Raman assignment, and the kinetic parameters are acquired. A catecholate ligand binds to a five-coordinated surface Ti of Ti17 (denoted as Tia site) adopting the mono-protonated, chelate-bidentate binding mode, whereas it binds to a six-coordinated surface-Ti (denoted as Tib site) adopting the mono-dentate mode. With low numbers of equivalents of added catechols the Tia sites show higher reactivity than the Tib sites toward functionalization. Two binding modes may co-exist and equilibrate in solution. Our results also imply that at most eight of the twenty Oi C3 H7 ligands of Ti17 are exchangeable without damage of the core structure. The kinetic studies point out that the ligand-exchange reaction is second order and occurs very fast. The current findings are helpful for the controlled functionalization of Ti17 and other Ti oxide clusters, and the further application of them as building blocks in supramolecular chemistry for the assembly of well-defined organic-inorganic hybrid materials.

Phenolic organic contaminants (POCs) in water environment have been usually degraded by advanced oxidation processes (AOPs) based on sulfate radicals ( SO 4 · - ) and hydroxyl radicals ( OH). In this paper, the first step of SO 4 · - / · OH -initiated oxidation reactions toward 19 POCs were investigated using density functional theory (DFT) in order to explore and compare the reactivity of POCs with two free radicals in the aqueous phase. The oxidation reactions initiated by SO 4 · - / · OH were confirmed that POCs can follow three reaction mechanisms: radical adduct formation (RAF), hydrogen atom abstraction (HAA), and single electron transfer (SET). The rate constants of all primary oxidation reactions were calculated using transition state theory (TST). The results turn out that the stronger the electron donating effects of the substituent on POCs, the better the reactivity of POCs with two free radicals. SET mechanisms are main reaction pathways for SO 4 · - -initiated oxidation reactions. Furthermore, the ecotoxicity assessment shows that most OH adducts have higher toxic on aquatic organisms than corresponding reactants. For all the POCs covering in this work, the order of acute toxicity is p-DP > o-AP > m-AP (p-AP) > MP > CP > NP > m-DP (o-DP) > phenol > YP, while the chronic toxicity is in the order p-DP > o-AP > m-AP (p-AP) > MP > CP > NP > YP > phenol > m-DP (o-DP). Thus, the application of AOPs for the removal of POCs should be taken seriously.

As an excellent conductive herbicide, swep is widely used in weed removal. Its remaining in atmosphere and water can not only contaminate the environment but also pose a threat to human health. This work presented a systematic theoretical study of HO•-mediated degradation mechanisms and kinetics of swep in atmosphere and water environment. HO•-addition reaction was the dominant reaction type and the main degradation products N-(3-chloro-4-hydroxyphenyl)carbamate (P2), N-(3,4-chloro-6-hydroxyphenyl)carbamate (P3) and N-(3,4-chloro-2-hydroxyphenyl)carbamate (P11) were in good agreement with the experimental results. The total rate constants of swep with HO• were determined to be 3.37 × 10−12 and 7.73 × 10−12 cm3 molecule−1 s−1 (at 298 K) in atmosphere and water environment, respectively. As an excellent adsorbent and photocatalyst, zinc oxide (ZnO) was selected to study the adsorption and catalytic degradation mechanism of swep. The adsorption configuration of (ZnO)n clusters with swep was most stable when n = 6. The adsorption of (ZnO)6 cluster was more favorable to the H-atom abstraction reaction. The toxicities of swep and its degradation products to aquatic organisms were predicted. The degradation of swep induced by HO• was beneficial to the survival of aquatic organisms. This work would provide a comprehensive theoretical basis for understanding the degradation behavior of organic pollutants.

In this work, cystine-glucose Maillard conjugates were composited with Cu

This study puts forward a new way to produce montmorillonite immobilized bimetallic nickel-iron nanoparticles by dry in-situ hydrogen reduction method in the non-liquid environment, which effectively inhibits the oxidation of iron and nickel during the synthesis process and improves the reactivity of the material. The degradation of 4-Chlorophenol (4-CP) was investigated to examine the catalytic activity of the material. The morphology and crystal properties of the montmorillonite-templated Fe/Ni bimetallic particles were explored by using scanning electron microscopy, transmission electron microscopy, X-ray diffraction studies, and energy dispersive X-ray spectroscopy analysis. Results suggest that Fe and Ni particles were homogeneously dispersed on the montmorillonite. The optimization of Ni content and reduction temperature over the degradation of 4-CP was also studied. The introduction of Ni intensely improved the degradation of 4-CP and reached over 90% when Ni content was 28.5%. The degradation rate increased significantly with the increase of reduction temperature and showed maximum activity at the reduction tempreature of 800 °C. This study offers a new method to fabricate montmorillonite immobilized Fe/Ni bimetallic nanoparticles in the non-liquid environment and the composites exhibited high degradation activity to chlorinated organic compounds.

The magnetic biochar (γ-Fe2O3@BC) derived from banana peels was synthesized by a facile one-pot thermal process and used as the cost-effective and recyclable persulfate (PS) activator for organic contaminants degradation. The results showed that the encapsulated iron oxide nanoparticles not only introduced the magnetism into biochar for easy separation, but also influenced the catalytic ability for PS activation. The γ-Fe2O3@BC was found to be highly effective for bisphenol A (BPA) degradation without pH adjustment. A complete removal of BPA was obtained within 20 min with an observed rate constant (kobs) of 0.1849 min−1, which was almost two times as large as that (0.0956 min−1) of pure biochar. Further, it exhibited high mineralization efficiency for the degradation of various organic contaminants. The high catalytic activity could be attributed to large BET surface area, dispersed iron species, abundant oxygen functional groups and rich doped nitrogen. Radical quenching experiments and electron spin resonance (ESR) studies confirmed that OH , SO4 − and O2 − were all involved in the radical oxidation process which was responsible for BPA degradation. A mechanism of PS activation by the γ-Fe2O3@BC catalyst was proposed based on the synergistic effect of biochar and iron.

In this study, a flower-like Cu2FeSnS4 (CFTS) nanomaterial was applied to the activation of persulfate (PS) for the degradation of bisphenol A (BPA) in model industrial wastewater. The efficiency of PS decomposition by CFTS, and the mechanism of contaminant degradation by SO4 − were investigated. The results revealed that CFTS catalyzes PS decomposition more efficiently than the monometallic Cu/Fe/Sn sulfides and exhibits activity over a wide pH range. Electron spin resonance spectroscopy, X-ray photoelectron spectroscopy, and free radical quenching experiments revealed a tandem synergistic effect between Cu, Fe, and Sn in their quaternary chalcogenide systems upon PS activation. The intrinsic electron transfer between Cu, Fe and Sn, especially the Fe(II)* species formed upon the complexation of Fe(II) by S on the surface of the CFTS, overcomes the inhibition of the M(n+1)+/Mn+ redox cycle. CFTS shows promise as a catalyst for wastewater treatment.

In this work, monochlorophenols (MCPs) isomers degradation was investigated by Co-doped g-C3N4 (CCN) using peroxymonosulfate (PMS) as the oxidant. The effects of the doping amount of Co, the concentration of PMS, the loading of catalyst and initial pH of the solution on the catalyst activity were systematically studied. The results showed that MCPs could be degraded effectively by CCN/PMS system. The degradation reaction followed pseudo-first order kinetics. Sulfate radical (SO4 −) was found as the major active radicals in the degradation process. MCPs were degraded effectively with the degradation rate order of 2-chlorophenol (2-CP) > 3-chlorophenol (3-CP) > 4-chlorophenol (4-CP). Except for the influence of structural characteristics of MCPs, this degradation rate order was also related to the adsorption behavior of CCN, which was based on the intermolecular interaction. Based on the analysis of the degradation products of MCPs, 1,4-benzoquinone or chlorinated 1,4-benzoquinone had been found to be the main intermediates.

The extensive use of chlorobenzene in chemical, pharmaceutical, and agrochemical industries poses a severe health hazard to human beings, because it is highly toxic. The detection of chlorobenzene by metal oxide gas sensors is difficult, owing to its chemically inert molecular structure. In this study, well-dispersed Pd nanoparticles were deposited on porous ZnO nanoplates via surface ion exchange, followed by H2 reduction. The preparation process effectively prevented the aggregation and uncontrollable growth of Pd particles. A gas-sensing test was conducted, and the modification of size-controlled Pd nanoparticles was found to effectively enhance the sensing properties of porous ZnO nanoplates to chlorobenzene over 300 °C (higher sensitivity at a low operating temperature). At 440 °C, 5% Pd@ZnO sensor showed a drastic increase in response by nearly 4.5-fold, as well as excellent sensing selectivity to chlorobenzene. Its repeatability and stability were acceptable. As known, Pd nanocatalysts contribute to the oxidation of chlorinated aromatic compounds. Pd@ZnO sensors generated more catalytic sites and oxygen species (confirmed by XPS), thus enhancing chlorobenzene oxidation and improving the sensitivity of ZnO-based gas sensors.

The solar/chlorine and UV/chlorine systems as emerging advanced oxidation technologies (AOTs) are used for degrading trace organic contaminants (TrOCs) through generating various radical species. The pH is a vital parameter that significantly affects the degradation efficiency of contaminants. In this study, six aromatic acids and bases (AABs) are selected to investigate the pH-dependent degradation mechanisms and kinetics by two newly-discovered radicals (ClO• and BrO•). Among the 16 dissociation species, the structures with electron-rich rings possess stronger reactivities to ClO• and BrO• than those with electron-poor rings, which is similar to the result of HO•. However, ClO• and BrO• are considered to be more selective and pH-sensitive reacting with AABs than HO• based on the corresponding second-order rate constants (M−1 s−1). Compared with acidic pH, the basic pH could improve the degradation rate of most aromatics in both systems. As pH increases from 6 to 8, the contribution percentages of ClO• in terms of the removal of the aromatics (except for benzoic acid) in solar/chlorine rise more rapidly (from 0.33 ∼ 61.34% to 94.23 ∼ 99.09%) than those in UV/chlorine system (from 19.14 ∼ 99.60% to 96.75 ∼ 99.88%). The pH-dependent contributions of various radical species are attributed to structure-dependent reactivities of compounds and pH-dependent concentrations of radical species. As the dose of Br- increases from 0 to 10 μM, the contributions of BrO• to the removal of aromatics (except for benzoic acid) increase from 0% to 10.28 ∼ 19.32%, thanks to the increased [BrO•]ss. This work is necessary for enhancing the understanding of the pH-dependent contributions of individual species during the removal of dissociable aromatic contaminants in light/chlorine systems.

The development of high-quality flexible surface-enhanced Raman spectroscopy (SERS) substrates is crucial for developing rapid SERS analysis in situ. Silver nanowire membranes as novel flexible substrates could benefit from the high collection efficiency of analytes by wrapping complex surfaces or wiping the surfaces of samples. However, their low SERS performance impedes further applications of silver nanowire membranes in analyte detection. Herein, we report an ultra-high-sensitivity silver nanowire membrane synthesized by a simple and time-saving cyclic voltammetry (CV) method. After CV treatment, a part of the silver nanowires on the silver nanowire membrane turned into small nanoparticles and nanorods. This nanostructure’s reconstitution increased the analytical enhancement factor of silver nanowire membranes by 14.4 times. Scanning and transmission electron microscopy, UV-vis spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were employed to investigate the transformation in the membrane nanostructure. The CV-treated substrates exhibited high surface-enhanced Raman activity and good temporal stability. The limits of detection (LODs) for p-aminothiophenol, crystal violet, tetramethylthiuram disulfide, sodium perchlorate, malachite green, fluoranthene, and potassium nitrate are 3.7 × 10−12 M, 5.1 × 10−11 M, 5.4 × 10−11 M, 6.3 × 10−9 M, 0.00693 ng, 0.0810 ng, and 0.0273 ng on this substrate, respectively. Additionally, the developed substrate is feasible for the detection of crystal violet in real samples. These results certify that CV-treated substrates possess broad application prospects in on-site SERS analysis.

The research on the mechanisms and kinetics of radical oxidation in peracetic acid-based advanced oxidation processes was relatively limited. In this work, HO• and organic radicals mediated reactions of acetaminophen (ACT) were investigated, and the reactivities of important organic radicals (CH3COO• and CH3COOO•) were calculated. The results showed that initiated reaction rate constants of ACT are in the order: CH3COO• (5.44 × 1010 M−1 s−1) > HO• (7.07 × 109 M−1 s−1) > CH3O• (1.57 × 107 M−1 s−1) > CH3COOO• (3.65 × 105 M−1 s−1) >> •CH3 (5.17 × 102 M−1 s−1) > CH3C•O (1.17 × 102 M−1 s−1) > CH3OO• (11.80 M−1 s−1). HO•, CH3COO• and CH3COOO• play important roles in ACT degradation. CH3COO• is another important radical in the hydroxylation of aromatic compounds in addition to HO•. Reaction rate constants of CH3COO• and aromatic compounds are 1.40 × 106 – 6.25 × 1010 M−1 s−1 with addition as the dominant pathway. CH3COOO• has high reactivity to phenolate and aniline only among the studied aromatic compounds, and it was more selective than CH3COO•. CH3COO•-mediated hydroxylation of aromatic compounds could produce their hydroxylated products with higher toxicity.

As one of the main components of combustion of tobacco products occurs (CARB), crotonaldehyde has an acute toxicity and widely exists in the atmosphere, which is harmful to human health. The removal efficiency of VOCs by ozonation can reach 80–90%. Based on the theory of quantum chemistry, the degradation mechanism, kinetics and toxicity of crotonaldehyde by ozonation in gas phase and heterogeneous phase were studied. Ozone was added to the olefins unsaturated double bond to form a five-membered ring primary ozonide, which was further fractured due to its unstable structure to form a Criegee intermediate and an aldehyde compound. The reaction rate constant of crotonaldehyde with ozone was 1.24 × 10−17 cm3 molecule−1 s−1 at 298 K and 1 atm, which was an order of magnitude higher than the experimental value. From toxicity assessment, it was found that the ozonation of crotonaldehyde is beneficial to the removal of toxicity. Mineral dust aerosol exists in the atmosphere in large quantities, and SiO2 is the most abundant component. VOCs are transformed into particle state on their surface through homogeneous nucleation and heterogeneous nucleation. Referring to the crystal structure of SiO2, five hydroxylated silica oligomer cluster structures were simulated and the adsorption configurations of crotonaldehyde on their surface were simulated. The adsorption of crotonaldehyde on the surface of the clusters was achieved by forming hydrogen bonds and had good adsorption effects. The adsorption of hydroxylated silica oligomer clusters didn't change the ozonation mechanism of crotonldehyde, but had a certain effect on the reaction rate.

The carbon catalyst has been widely used as a peroxymonosulfate (PMS) activator to degrade organic contaminants. The biomass carbon aerogel (CA) derived from poplar powder was synthesized in this study. CA with three-dimensional structure exhibited an excellent degradation performance of PMS activation for different types of organic contaminants including bisphenol A (BPA), rhodamine 6 G, phenol, and p-chlorophenol with the removal efficiencies up to 91%, 100%, 100%, and 60% within 60 min, respectively. It was found that singlet oxygen (1O2) dominated the non-radical pathway worked for BPA removal in CA/PMS system. The possible mechanism for PMS activation was discussed. A portion of 1O2 was produced through the transformation of superoxide radical (O2•-) in CA/PMS system. Electronic impedance spectroscopy (EIS) proved that the hierarchical structure of CA contributed to the electron transfer process for PMS activation. The ketonic/carbonyl groups (C˭O) on the surface of CA could serve as a possible active site to facilitate the generation of 1O2. In addition, CA showed superior degradation performance in actual water bodies and reusability with high-temperature regeneration treatment. This study developed an efficient and environmentally benign catalyst for water remediation of organic pollutants.

Superstructures have attracted attention because of their potential applications in chemistry and materials science. In this work, we report the preparation of a porous 3D superstructure of nitrogen-doped carbon decorated with ultrafine cobalt nanodots (Co@NCSS) derived from the self-assembly of polyimide nanoparticles. Utilizing modified ultra-small cobalt nanodots as main catalytically active sites, and the excellent quality and electron transport efficiency generated by this 3D porous superstructure, Co@NCSS exhibited excellent catalytic performance as a peroxymonosulfate (PMS) activator towards the degradation of several sulfonamides. Based on radical scavenging tests and electron paramagnetic resonance (EPR), singlet oxygen (1O2) was the dominant oxidative species. Furthermore, through the identification of degradation intermediates by HPLC-MS and DFT calculation, the pathway of sulfamethoxazole (SMX) degradation by Co@NCSS/PMS was analyzed. The possible catalytic mechanism of Co@NCSS/PMS for SMX degradation is also proposed in this paper. Co@NCSS has the potential to be an ideal material for removing antibiotics from wastewater.

Novel SERS substrates is urgently in demand for rapid and sensitive analysis of toxic agrochemicals from food. In this work, a monodispersed tungsten disulfide quantum dots modified silver nanosphere (Ag@WS

Carbonaceous shell-coated γ-Fe2O3 nanoparticles (γ-Fe2O3@CNM) were synthesized from glucose caramelization and used as a novel magnetic solid-phase extraction medium for malachite green and crystal violet in environmental water. Malachite green and crystal violet were absorbed on to γ-Fe2O3@CNM by electrostatic and π-interactions. The morphologies, pore structures, surface functional groups, and magnetic properties of γ-Fe2O3@CNM were characterized by TEM, FTIR, hysteresis regression, Brunauer-Emmet-Teller analysis, zeta potential, XPS, and XRD. The magnetic solid-phase extraction procedure was optimized by extraction pH, absorption time, desorption solvent, and desorption time. The absorption capacities (qmax values) for malachite green and crystal violet were 34.2 and 27.9 mg g−1, respectively. After magnetic solid-phase extraction, malachite green and crystal violet were determined by LC-MS/MS. The analytical method was validated with a linear range of 0.02–20 ng mL−1, enrichment factor of 25.8 and 25.4, method detection limit of 0.004 ng mL−1, and intra-day precisions of 2.1% and 2.6% for malachite green and crystal violet, respectively. The relative recovery was found to be 73.4–101.5% for malachite green and 83.1–102.7% for crystal violet upon the application of the magnetic solid-phase extraction method to real water samples from lake, spring, sea, fishpond, and industrial waste.

Syringol and syringaldehyde are widely present pollutants in atmosphere and wastewater due to lignin pyrolysis and draining of pulp mill effluents. The hydroxylation degradation mechanisms and kinetics and health effect assessment of them under high and low-NO

Integrated theranostic agents can provide multifunctional platforms for synergetic cancer diagnosis and therapy. However, the efficiency and safety of agents are of great concern. In this work, we prepared biocompatible and pH-sensitive MnO-loaded carbonaceous nanospheres (MnO@CNSs) for simultaneous magnetic resonance imaging (MRI) and photothermal therapy (PTT). Carbonaceous nanospheres (CNSs) with biocompatibility and unique optical properties were prepared by hydrothermal method for photothermal absorption and released Mn2+ were used for MRI. In vitro the results of MRI T1 relaxivity test showed r1 value in the acidic environment with an increase by 5-fold (from 5.42 mM−1s−1 to 0.18 mM−1s−1), due to excellent pH responsiveness. In addition, MRI and photothermal effect for mouse model showed enhanced T1 signal and temperature elevation in tumor site with photoirradiation. All the aforementioned results embodied that MnO@CNSs can be used as a fine biocompatible and pH-sensitive contrast for combining targeted MRI with accurate photothermal therapy, showing important value and potential in the integration of theranostics of cancer.

Wastewater systems contain a large number of compounds, such as anthropogenic aromatic pollutants and natural organic matter (NOM), and usually have pH higher than 4. Fenton-like reaction is the most widespread method for removal of organic pollutants, but their reactivity with H2O2 may be inhibited by NOM due to the competition of hydroxyl radicals and chelating agents. In this work, Cu2O@β-cyclodextrin was developed to achieve the collaboration between molecular recognition and Fenton-like catalysis to destruct aromatic pollutants at neutral pH. In Cu2O@β-CD, covalent Cu O C bond was topotaxially converted from CuCl assisted by β-CD at room temperature. Covalently linked β-CD could keep humic acid from interfering catalytic performance of Cu2O surfaces and inhibit the leaching of copper. A higher catalytic ability was observed for Cu2O@β-CD with rate constant 0.0331 min−1 than Cu2O (0.0064 min−1) at neutral pH. A mechanism of synergistic catalysis was proposed on the basis of Cu+, β-CD and phenoxo-Cu2+ complexes in the Cu2O@β-CD/BPA/H2O2 system. The strategy of coupling molecular recognition into Fenton-like reaction provides an efficient and promising approach to the destruction of aromatic pollutants at neutral pH.

In this study, superparamagnetic β-CD-MnFe

Aim: To elucidate the MRI mechanisms of manganese oxide-coated carbohydration nanosphere (Mn@CNS) for active targeting in hepatobiliary tumors. Materials & methods: The cytotoxicity, internalization pathway, metabolism and excretion pathway of Mn@CNS were assessed by several cell types. The MRI of Mn@CNS was verified via rat models bearing hepatobiliary tumors. Results: Mn@CNS showed no obvious cytotoxicity. Mice macrophage and hepatocellular Mn content significantly differed between pre- and post-uptake levels (p

Peroxymonosulfate (PMS) activation by heterogeneous catalysts has been widely investigated to remove organic contaminants. Nevertheless, the technology is restricted to the bench-scale batch system. For practical applications, a supported catalyst design based on a reactor configuration with catalyst recovery is the need for future development. In this study, Mn

The extensive use of chlorobenzene in chemical, pharmaceutical, and agrochemical industries poses a severe health hazard to human beings, because it is highly toxic. The detection of chlorobenzene by metal oxide gas sensors is difficult, owing to its chemically inert molecular structure. In this study, well-dispersed Pd nanoparticles were deposited on porous ZnO nanoplates

Carbonaceous shell-coated γ-Fe

Prosulfocarb (PSC) is a thiocarbamate herbicide mainly used in winter cereals and a relevant aerosol precursor under OH radicals ( OH) photooxidation conditions. We investigated the environmental risks, mechanisms, kinetics and products for the PSC with OH by employing theoretical chemical calculations. Two reaction types of H-abstraction and OH-addition reactions were taken into account. Whether in the atmosphere or aqueous particles, the most favorable pathway was the H-abstraction in the N-alkyl groups close to nitrogen atom. Subsequent reactions of primary intermediates were considered at different conditions. The total rate constants were determined as 2.62 × 10-10 cm3 molecule-1 s-1 and 4.96 × 10–11 cm3 molecule-1 s-1 at 298 K in atmosphere and aqueous particles, respectively. In natural water with the OH concentration of 10–15-10-18 mol l-1, the half-lives (t1/2) of PSC in the OH-initiated reactions were calculated as t1/2 = 2.40 × 104–2.40 × 107 s. With regard to the influence on human health and the ecosystem, oxidized products of PSC were estimated to be mutagenicity negative and had no obvious bioaccumulation potential. The aquatic toxicity of PSC and its degradation products was evaluated and the assessment results showed that the degradation of PSC was a toxicity-reduced process but they were still at toxic and harmful levels.

Novel In2O3-SnO2 hybrid sensing nanostructures with porous nature were successfully prepared and characterized by various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM). Gas sensing properties of the fabricated sensor based on the as-prepared In2O3-SnO2 hybrid nanostructures were systematically investigated and compared with those of pure SnO2. The hybrid nanostructures containing 3% In2O3 exhibit the highest response value of 30.7–100 ppm formaldehyde at 100 °C, which was 14 times higher than that of pure SnO2. Moreover, gas sensors based on the as-prepared In2O3-SnO2 hybrid nanostructures also exhibit high stability and good selectivity for formaldehyde. The enhanced sensing performances of formaldehyde were mainly attributed to the formation of n-n heterojunctions and the synergistic interaction between In2O3 and SnO2.

The indoor volatile organic compounds (VOCs) have caught much attention because millions of people are suffering from indoor air pollution. To detect VOCs, various gas sensors with fast response, high sensitivity and high stability have been fabricated by nanocomposite technology. In this study, highly dispersed Au nanoparticles are deposited on porous ZnO nanoplates (Au@ZnO) via ion exchange method from hydrozincite [Zn 5 (CO 3 ) 2 (OH) 6 ] without the addition of any surfactants. By immersing hydrozincite precursors into 0.1%–5% HAuCl 4 solutions and followed by annealing, several Au@ZnO sensors with size-limited Au nanoparticles are fabricated for the detection of nine types of VOCs. Comparing with pure ZnO nanoplates, the as-prepared Au@ZnO sensors show enhanced sensitivity by 2–9 times at 400 °C toward all nine types of VOCs. Also, fast response/recovery time and fine repeatability in the gas-sensing tests are attained. More oxygen species and active sites to the adsorbed VOCs molecules are generated by Au@ZnO hybrids, which lead to the improvement of ZnO-based gas sensor limitation.

The development of solid phase extraction (SPE) combined with the sensitive detection of surface-enhanced Raman spectroscopy (SERS) has been successfully applied for the analysis of complex environmental samples. In this work, a silver nanoplate-decorated copper membrane was fabricated as a recyclable SERS-active SPE substrate. The membrane was fabricated via modified galvanic displacement on a commercial copper membrane. Compared with filter paper SERS substrates, the as-synthesized substrate has relatively rapid heat conduction, which can lead to a greater temporal stability under continuous laser irradiation conditions. The relative standard deviation (RSD) value of the intensity change is 0.31%. The experimental results also showed that these substrates have a long life and are reproducible even after 5 cycles. The RSD was calculated to be 12.13%, which indicates that this method was recyclable. The signal intensity of filtering is almost 28 times higher than that of the traditional dropping method, which proves that the membrane has rapid extraction ability. The qualitative and quantitative detection of phorate was investigated based on a flow-through method. A good linearity (R2 = 0.98) was achieved for phorate in the concentration range of 3.84 to 288 nmol L−1. In addition, the simulated detection of phorate in actual water such as underground water, surface water, and drinking water was also studied. These results demonstrated its practical application to rapidly detect phorate in the real environment.