Chemical Characterization Research Articles

Chemically Synthesized 1,2,3,4,6-Pentakis-O-Galloyl-β-D-Glucopyranoside Blocks SARS-CoV-2 Spike Interaction with Host ACE-2 Receptor.

In the search for anti-COVID-19 therapy, 1,2,3,4,6-pentakis-O-galloyl-βD-glucopyranoside, a natural polyphenolic compound isolated from many traditional medicinal herbs, has been reported as an RBD-ACE2 binding inhibitor and as a broad-spectrum anticoronaviral inhibitor targeting the main protease and RNA-dependent RNA polymerase of SARSCoV-2. To facilitate the structure-activity relationship studies of 1,2,3,4,6-pentakis-O-galloyl-β-Dglucopyranoside, we describe its chemical synthesis and characterization, as well as its activity towards the SARS-CoV-2 spike interaction with host ACE2 receptor. 1,2,3,4,6-Pentakis-O-galloyl-β-D-glucopyranoside was synthesized in two quantitative steps from 3,4,5-tribenzyloxybenzoic acid and β-D-glucopyranoside: DCC-mediated esterification and palladium-catalyzed per-debenzylation. The synthesized molecule was evaluated using a SARS-CoV-2 spike trimer (S1 + S2) ACE2 inhibitor screening colorimetric assay kit, SARS-CoV2 spike S1 RBD ACE2 inhibitor screening colorimetric assay kit, and a cellular neutralization assay using the Spike (SARS-CoV-2) Pseudotyped Lentivirus, ACE2-HEK293 recombinant cell line. The chemically synthesized product blocked the binding of the spike trimer of SARSCoV-2 to the human ACE2 receptor with IC50=22±2 µM. It also blocked ACE2:spike RBD binding with IC50=27±3 µM. Importantly, it inhibited the infectivity of SARS2-CoV2-Spike pseudotyped lentivirus on the ACE2 HEK293 cell line with IC50=20±2 µM. Overall, the chemically synthesized 1,2,3,4,6-pentakis-O-galloyl-β-D-glucopyranoside represents a lead molecule to develop anti-SARS-CoV-2 therapies that block the initial stage of the viral infection by blocking the virus entry to the host cell.

One-Step Electrochemical Synthesis of Molybdenum-Disulfide-Based Materials for Enhanced Supercapacitor Performance

Abstract Molybdenum disulfide (MoS2)-based two-dimensional materials were produced in one-step at room temperature using cyclic voltammetry technique. These materials were then used as electrode materials in supercapacitors. Concentration of supporting electrolyte, precursor, and cycle number parameters, which were the factors affecting the success of the synthesis, were optimized as 0.5 M, 0.15 M,and 10 cycles, respectively. The produced MoS2-coated electrodes were characterized using spectroscopic and microscopic methods. The chemical characterizations of the produced materials were examined by X-ray photoelectron spectroscopy, X-ray diffraction diffractometry, and scanning electron microscopy-energy-dispersive X-ray analysis. Surface morphologies of the composite materials were investigated using scanning electron microscopy. Finally, the produced MoS2-based materials were used as electrode materials in supercapacitors. The produced supercapacitors were characterized using cyclic voltammetry and electrochemical impedance spectroscopy methods, and the changes in the capacitive behavior of these systems over cycles were investigated using the cyclic charge-discharge technique. The highest areal capacitance value was determined as 251 mF.cm-2 at 0.2 mA.cm-2 charge-discharge current rates in 1.0 M H2SO4 by using of MoS-AD1 as the electrode material. Capacitance retention of this electrode was over 100% after 4000 cycles.

Elderberry Hydrolate: Exploring Chemical Profile, Antioxidant Potency and Antigenotoxicity for Cosmetic Applications

Elderberry (Sambucus nigra L.) hydrolate, derived from domestic steam distillation, holds promise as a multifunctional ingredient for skincare and cosmetic applications. This study investigates the chemical composition and biological activities of elderberry hydrolate obtained through steam distillation. Despite the growing interest in elderberry hydrolate, there has been a lack of comprehensive studies elucidating its chemical composition and potential bioactive constituents. To address this gap, we conducted a detailed analysis of elderberry hydrolate’s composition, antioxidant activity, and antigenotoxicity. Genotoxic evaluation and antioxidant assays (ABTS, DPPH) were conducted to assess its biological properties. We obtained elderberry hydrolate with a notable transfer of aromatic compounds through the steam distillation process, highlighting its efficacy and sustainability. The chemical characterization identified vital compounds, including phenylacetaldehyde, 2-acetyl-pyrrole, and an unidentified major component, collectively contributing to the hydrolate’s aromatic and biological properties. The genotoxic evaluation using the Comet assay demonstrated the hydrolate’s protective effects against DNA damage induced by hydrogen peroxide and streptonigrin. The optimal DNA protection was observed at 10% (w/v), attributed to the antioxidant activity of the identified compounds. The hydrolate exhibited significant antioxidant potential, demonstrating concentration-dependent responses and correlating higher concentrations with increased antioxidant activity. These findings underscore the multifaceted attributes of elderberry hydrolate, positioning it as a promising natural ingredient for skincare. This study supports elderberry hydrolate as a valuable natural and sustainable product development resource.

Elucidating bacterial coaggregation through a physicochemical and imaging surface characterization

Bacterial coaggregation is a highly specific type of cell-cell interaction, well-documented among oral bacteria, and involves specific characteristics of the cell surface of the coaggregating strains. However, the understanding of the mechanisms promoting coaggregation in aquatic systems remains limited. This gap is critical to address, given the broad implications of coaggregation for multispecies biofilm formation, water quality, the performance of engineered systems, and diverse biotechnological applications. Therefore, this study aims to comprehensively characterize the cell surface of the coaggregating strain Delftia acidovorans 005P, isolated from drinking water, alongside a non-coaggregating strain, D. acidovorans 009P. By analyzing two strains of the same species, we aim to identify the factors contributing to the coaggregation ability of strain 005P. To achieve this, we employed a combination of physicochemical characterization, Fourier-transform infrared spectroscopy (FTIR), and advancing imaging techniques [transmission electron microscopy and cryo-electron tomography (cryo-ET)]. The coaggregating strain (005P) exhibited higher surface hydrophobicity, negative surface charge, and cell surface and co-adhesion energies than the non-coaggregating strain (009P). The chemical characterization of bacterial surfaces through FTIR revealed subtle differences, particularly in spectral regions linked to carbohydrates and phosphodiesters/amide III of proteins (860–930 cm−1 and 1212–1240 cm−1, respectively). Cryo-ET highlighted significant differences in pili structures between the strains, such as variations in length, frequency, and arrangement. The pili in the 005P strain, identified as pili-like adhesins, serve as key mediators of coaggregation. By integrating physicochemical analyses and high-resolution imaging techniques, this study conclusively links the coaggregation ability of D. acidovorans 005P to its unique pili characteristics, emphasizing their crucial role in microbial coaggregation in aquatic environments.

Sorbate metal complexes as newer antibacterial, antibiofilm, and anticancer compounds

BackgroundThe ineffectiveness of treatments for infections caused by biofilm-producing pathogens and human carcinoma presents considerable challenges for global public health organizations. To tackle this issue, our study focused on exploring the potential of synthesizing new complexes of Co(II), Cu(II), Ni(II), and Zn(II) with sorbic acid to enhance its antibacterial, antibiofilm, and anticancer properties.MethodsFour novel complexes were synthesized as solid phases by reacting sorbic acid with Co(II), Cu(II), Ni(II), and Zn(II). These complexes were characterized by various technique, including infrared spectra, UV–Visible spectroscopy, proton nuclear magnetic resonance (1H NMR), and thermal analysis techniques, including thermogravimetry (TG).ResultsThe data acquired from all investigated chemical characterization methods confirmed the chemical structure of the sorbate metal complexes. These complexes exhibited antibacterial and antibiofilm properties against both Gram-positive and Gram-negative bacteria. Furthermore, these complexes enhanced the antibacterial effects of commonly used antibiotics, such as gentamicin and imipenem, with fractional inhibitory concentration (FIC) indices ≤ 0.5. Notably, the Cu(II) complex displayed the most potent antibacterial and antibiofilm activities, with minimum inhibitory concentration (MIC) values of 312.5 µg/mL and 625.0 µg/mL for Bacillus cereus and Escherichia coli, respectively. Additionally, in vitro assays using the methyl thiazolyl tetrazolium (MTT) method showed inhibitory effects on the growth of the human colon carcinoma cell line (HCT-116 cells) following treatment with the investigated metal complexes. The IC50 values for Co(II), Cu(II), Zn(II), and Ni(II) were 3230 µg/mL, 2110 µg/mL, 3730 µg/mL, and 2240 µg/mL, respectively.ConclusionOur findings offer potential for pharmaceutical companies to explore the development of novel combinations involving traditional antibiotics or anticancer drugs with sorbate copper complex.

Chemical characterization and antibacterial activities of Brazilian propolis extracts from Apis mellifera bees and stingless bees (Meliponini).

The aim of this study was to evaluate the physicochemical composition and antibacterial activity of Brazilian propolis extracts from different types, concentrations, and extraction solvents and from different regions in Brazil. A total of 21 samples were analyzed, comprising 14 samples from Apis mellifera (12 green, 1 brown, and 1 red) and 7 samples from stingless bees (3 mandaçaia, 2 jataí, 1 hebora, and 1 tubuna). The analyses performed were dry extract, total phenolic content (TPC) and antioxidant activity (DPPH and ABTS). The antibacterial activity was performed by Determination of Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC). The results showed that very low levels of phenolic compounds and antioxidant activity decreased the antimicrobial activity of the propolis extracts from tubuna and jataí. However, there was no correlation between the increase in propolis concentration in the extract, and the increase in antimicrobial activity. The highest TPC and antioxidant activity was obtained for green propolis extract made with 70% raw propolis that presented similar antibacterial activity to the samples formulated with 30% or less raw propolis. The aqueous propolis extract showed lower antimicrobial activity compared to the alcoholic extracts, indicating that ethanol is a better solvent for extracting the active compounds from propolis. It was observed that the MIC (0.06 to 0.2 mg/mL) and MBC (0.2 to 0.5 mg/mL) values for Gram-negative bacteria were higher compared to Gram-positive bacteria (MIC 0.001-0.2 mg/mL, and the MBC 0.02-0.5 mg/mL). The propolis extracts that exhibited the highest antimicrobial activities were from stingless bees hebora from the Distrito Federal (DF) and mandaçaia from Santa Catarina, showing comparable efficacy to samples 5, 6, and 7, which were the green propolis from the DF. Hence, these products can be considered an excellent source of bioactive compounds with the potential for utilization in both the pharmaceutical and food industries.

Chemical characterization of lithium based ceramics utilizing charged particle activation and ion beam techniques

AbstractNon-destructive methodologies using activation analysis and ion beam analysis techniques were optimized for the chemical characterization of ceramic materials, lithium titanate and lithium niobate, which have application in tritium breeding blanket. The analyses were carried out as a part of chemical quality control exercise. The atomic ratios of Li/Ti, Li/Nb were quantified by charged particle activation analysis using 13 MeV proton beam from variable energy cyclotron facility and particle induced gamma ray emission/Rutherford backscattering spectrometry using 3 MeV/2 MeV proton beam from 3MV tandem accelerator facility. The results of these different analytical methods are in good agreement, which established the applicability of these activation analysis and ion beam techniques for the chemical characterization of these ceramic materials.

Effect of nanodiamonds surface deposition on hydrophilicity, bulk degradation and in-vitro cell adhesion of 3D-printed polycaprolactone scaffolds for bone tissue engineering

This study was designed to deposit nanodiamonds (NDs) on 3D-printed poly-ϵ-caprolactone (PCL) scaffolds and evaluate their effect on the surface topography, hydrophilicity, degradation, andin-vitrocell adhesion compared to untreated PCL scaffolds. The PCL scaffold specimens were 3D-printed by fused deposition modeling (FDM) technique with specific porosity parameters. The 3D-printed specimens' surfaces were modified by NDs deposition followed by oxygen plasma post-treatment using a plasma focus device and a non-thermal atmospheric plasma jet, respectively. Specimens were evaluated through morphological characterization by field emission scanning electron microscope (FESEM), microstructure characterization by Raman spectroscopy, chemical characterization by Fourier transform infrared (FTIR) spectroscopy, hydrophilicity degree by contact angle and water uptake measurements, andin-vitrodegradation measurements (n= 6). In addition,in-vitrobone marrow mesenchymal stem cells adhesion was evaluated quantitatively by confocal microscopy and qualitatively by FESEM at different time intervals after cell seeding (n= 6). The statistical significance level was set atp⩽ 0.05. The FESEM micrographs, the Raman, and FTIR spectra confirmed the successful surface deposition of NDs on scaffold specimens. The NDs treated specimens showed nano-scale features distributed homogeneously across the surface compared to the untreated ones. Also, the NDs treated specimens revealed a statistically significant smaller contact angle (17.45 ± 1.34 degrees), higher water uptake percentage after 24 h immersion in phosphate buffer saline (PBS) (21.56% ± 1.73), and higher degradation rate after six months of immersion in PBS (43.92 ± 0.77%). Moreover, enhanced cell adhesion at all different time intervals was observed in NDs treated specimens with higher nuclei area fraction percentage (69.87 ± 3.97%) compared to the untreated specimens (11.46 ± 1.34%). Surface deposition of NDs with oxygen-containing functional groups on 3D-printed PCL scaffolds increased their hydrophilicity and degradation rate with significant enhancement of thein-vitrocell adhesion compared to untreated PCL scaffolds.

Morphological, thermochemical, and rheomechanical evaluation of self-healing performance of asphalt binder modified with hybrid-structured phase change material capsules

Currently, sustainable pavement research focuses on modified asphalt binders with self-healing features for achieving durability and safety goals. This study assesses the self-healing behavior of asphalt binders incorporating innovative lab-manufactured hybrid-structured phase change material capsules (HPCMC). The HPCMC, using by-product paraffin oil as a core encapsulated by waste nano-silica fume as a shell, varied in core-to-shell ratios (0.5:1, 1:1, 2:1) and dosages (1 %, 3 %, 5 %, 7 %) by asphalt weight. Morphological, thermal, and chemical characterizations were conducted using scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). Healing efficiency of unaged and short-term aged HPCMC-modified binders was evaluated using SEM and energy dispersive X-ray (EDX) for morphological and chemical analysis. Rheomechanics were examined through rotational viscosity (RV), performance grading (PG), multiple stress creep recovery (MSCR), strain sweep (SS), frequency sweep (FS), linear amplitude sweep (LAS), and linear amplitude sweep-based healing (LASH). Study findings exhibit superior healing in HPCMC-modified binders compared to unmodified ones, particularly at a 3 % dosage and 1:1 core-to-shell ratio in unaged conditions. This study also evaluates healing assessment criteria and validates the self-healing mechanism, indicating significant potential for the proposed approach to revolutionize pavement construction and maintenance.

Biodegradable Films Added with Conjugates from Residual Agave vinasses: Chemical and Mechanical Characterization

Biodegradable Films Added with Conjugates from Residual Agave vinasses: Chemical and Mechanical Characterization

Application of Plant Antimicrobials in the Food Sector: Where Do We Stand?

The Special Issue “Plant Extracts Used to Control Microbial Growth: Efficacy, Stability and Safety Issues for Food Applications” explored the potential of plant-based extracts as natural antimicrobial agents in the food industry. Its purpose was to address the growing demand for natural, safe, and effective food preservation methods. The contributions highlighted various plant extracts’ antimicrobial efficacy, including phenolic compounds, terpenes, and other bioactive substances. Research papers and one review were submitted from countries, including Spain, Portugal, Italy, Mexico, Turkey, India, USA, Romania, China, and Lithuania, showcasing a diverse international collaboration. Key topics covered in this issue included the chemical characterization of plant extracts, their stability under different processing and storage conditions, and their safety assessments. Advances were reported in using plant extracts to inhibit spoilage microorganisms and foodborne pathogens, enhance food safety, and extend shelf life. The published papers in the Special Issue studied various food types, including yogurt, catfish fillets, edible Mushrooms, red grapes, herring Fillets, and various food types covered in the review. This diversity demonstrates the broad applicability of plant extracts across different food products. Notable findings included the antimicrobial activities of fermented grapevine leaves, grapefruit seed extract, cinnamaldehyde, clove oil, and other plant-based compounds. In conclusion, this Special Issue demonstrated significant progress in applying plant extracts for food preservation, highlighting their potential to contribute to safer and more sustainable food systems worldwide.

Insecticidal Properties and Chemical Characterization of Laurus nobilis L. Essential Oils from Two Regions of Morocco against Callosobruchus maculatus (Coleoptera: Bruchinae)

Morocco is a significant botanical reservoir that boasts a wealth of raw materials with promising applications across various industrial sectors, notably in pharmaceuticals and food. The objective of this study was to assess the effectiveness of essential oils (EOs) derived from Laurus nobilis L. leaves originating from the Tanger (EOT) and Meknes (EOM) regions in combating Callosobruchus maculatus infection. The chemical compositions of these oils were examined using Fourier transform infrared (FTIR) spectroscopy and gas chromatography–mass spectrometry (GC-MS). The biological activity of the EOs was evaluated via repulsion and fumigation tests against C. maculatus at varying concentrations. FTIR analysis revealed distinct vibrational bands indicative of various chemical compounds. GC-MS analysis was used to delineate the major chemical constituents of the EOs. The three predominant compounds in the EOT were 1,8-cineole (37.64%), linalool (16.40%), and adamantane (12.00%), whereas 1,8-cineole (47.84%), toluene (17.60%), and α-phellandrene (8.44%) were the most abundant in the EOM. Notably, the EOs exhibited significant repellent activity against C. maculatus, with repulsion percentages ranging from 51.11 to 90.00% in Tanger and 67.78 to 93.33% in Meknes. Mortality rates varied from 0 to 100% depending on the treatment. However, the mean concentrations showed mortality rates ranging from 29.44 to 65.56% for the EOT and from 21.11 to 67.78% for the EOM, with LD50 values of 11.96 μL/L and 5.22 μL/L. Docking studies revealed that 1,8-cineole had the highest binding affinity for the active site of acetylcholinesterase, thus confirming its toxic activity against C. maculatus. The findings of this study highlight the ability of EOs extracted from L. nobilis in the Moroccan regions of Tanger and Meknes to act as effective insecticides and repellents against C. maculatus, thereby highlighting avenues for further exploration of pest management and agricultural practices.

Chemical characterization and biological properties of oyster and shiitake mushrooms extracts and their liposomal formulations

In recent years, the production of liposomal formulations using mushroom extracts has gained increasing interest to increase the bioavailability of bioactive compounds in the nutraceutical field. Based on this information, we aimed to determine the antioxidant capacity (by DPPH, ABTS, CUPRAC and FRAP assays) and enzyme inhibition (against cholinesterase, amylase, glucosidase and tyrosinase) activities of alone and liposomal formulations of Pleurotusostreatus (OYE) or Lentinusedodes (SHE) in different extracts solvents which were methanol (MeOH), aqua (Aq), methanol/aqua (MeOH/Aq). The extracts and formulations were chemically characterized using HPLC-DAD. The mean diameter of SL:SHE and SL:OYE (in MeOH/Aq) extended in range between 60 and 165 nm. The entrapment yields of SL:SHE and SL:OYE (in MeOH/Aq) were 63.8% ± 3.7% and 71.2% ± 2.8%, respectively. HPLC-DAD analysis revealed that ferulic and cinnamic acids were main components in the liposomal formulations. Liposomal formulations (in MeOH) showed higher antioxidant activity in the FRAP and CUPRAC assays. SL:SHE (in Aq) showed effective enzyme inhibition activity on acetylcholinesterase, tyrosinase, amylase and glucosidase enzymes. Based on our findings, the liposomal formulations can be a valuable strategy in preparing functional applications with shiitake and oyster mushrooms.

Chemical Characterization and Biological Activities Evaluation of Myrtus communis L. Essential Oil Extraction By-Product Towards Circular Economy and Sustainability

Essential oil (EO) extraction is a widespread practice generating huge amounts of solid plant by-products a potential source of bioactive compounds, on the one hand, and a detrimental risk for the environment that needs to be carefully considered on the other hand. The present study aims to valorize Myrtus communis L. leaf by-products obtained following EO extraction using a steam distillation unit through the recovery of phenolic compounds and the evaluation of their biological activities. The total phenols, flavonoids, and proanthocyanidins contents of the ethanolic extract by-product were higher than the control (leaves without extraction of EO). Their amounts increased from 69.30 to 88.06 mg GAE/g for total phenols, from 36.31 to 70.97 mg QE for flavonoids and from 19.74 to 21.49 mg CE/g of extract for proanthocyanidins. The identification of phenolic compounds by high-performance liquid-chromatography equipped with a reversed-phase (RP-HPLC) system revealed that the by-product sample includes more gallic acid, catechin, syringic acid and luteolin 7-O-glucoside but less p-coumaric acid and kaempferol than the control. Moreover, the mid-infrared spectroscopy (MIR) showed the presence of benzene ring characteristic of phenolic compounds at 756 cm−1, esters of aromatic acids and stretching vibrations of polyphenols at 1141–1234 cm−1, C=C stretching present in phenolic acids such as coumaric acid and catechin at 1604 cm−1. The assessment of antioxidant activity revealed that the ABTS+• radical scavenging activity was significantly increased, whereas the DPPH• radical inhibition activity and the ferric reduction antioxidant power were significantly decreased. The results indicated, as well, that Myrtus communis L. leaf by-products maintained a considerable antibacterial activity depending on the tested bacterial strain. Additionally, the anti-α-amylase activity was higher for the Myrtus communis L. leaf by-product extract. Therefore, Myrtus communis L. leaf by-products of EO extraction offer phenolic compounds with significant biological activities, contributing to the sustainable development and the promotion of circular economy by the recovery of valuable inputs from plant by-products.

Chemical Characterization and Enantioselective Analysis of Tagetes filifolia Lag. Essential Oil and Crude Extract

Chemical Characterization and Enantioselective Analysis of Tagetes filifolia Lag. Essential Oil and Crude Extract

Assessment of the soil utilization potential of vanadium-titanium magnetite tailings based on a chemical, biological, and mineralogical characterization

Assessment of the soil utilization potential of vanadium-titanium magnetite tailings based on a chemical, biological, and mineralogical characterization

Chemical characterisation, thermal analysis, and antibacterial activity of honeys from Caatinga stingless bees of Melipona spp.

In the present study, chemical characterisation, thermal analysis and antibacterial activity of honeys from Melipona spp. with occurrence in Caatinga biome of Brazil. The honeys presented pH from 4.07 to 4.14, density of 1.41 g/cm3 and °Brix value of 79.90. The thermogravimetry (TG) analysis presented six-seven events and differential thermal analysis (DTA) presented three-four endothermic peaks. HPLC fingerprint revealed a predominant presence of gallic acid and vanillin. Antioxidant activity evaluated using in vitro 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging with IC50 values in the range of 14.5404 to 15.2454 mg/mL. The honeys also showed antimicrobial activities against Staphylococcus aureus and Pseudomonas aeruginosa using a modified agar diffusion and microdilution method. The results of the present study demonstrate that the honey from stingless bees by Caatinga biome indicate polyphenol compounds, antioxidant activity and in vitro antimicrobial potential. The analytical methos permitted of fingerprint of samples.

Lattice Distortion Promotes Carrier Separation to Improve the Photoelectrochemical Water Splitting Performance of Bismuth Vanadate Photoanode

AbstractThe poor carrier separation capability and sluggish water oxidation reaction kinetics are two critical factors that impact the photoelectrochemical (PEC) water splitting performance of the bismuth vanadate (BiVO4) photoanode. Previous studies have demonstrated that doping with rare‐earth elements to induce lattice distortions and loading oxygen evolution reaction (OER) co‐catalysts are effective strategies for enhancing carrier separation capabilities and accelerating the kinetics of the water oxidation reaction. Herein, Cu2+‐doped RuO2 (Cu‐RuO2) particles are anchored onto rare earth element Thulium (Tm)‐doped BiVO4 (Tm‐BiVO4) photoanode substrates, constructing an integrated Cu‐RuO2‐Tm‐BiVO4 photoanode. The newly integrated photoanode not only achieves a photocurrent density of 5.3 mA cm−2 at 1.23 V versus a reversible hydrogen electrode (vs RHE), but also exhibits exceptional stability. A series of detailed physical and chemical characterizations as well as density‐functional theory (DFT) calculations demonstrate that Tm doping induces lattice distortion in BiVO4, enhancing the internal electric field and thereby facilitating carrier separation. Moreover, the anchored Cu‐RuO2 particles not only lattice‐match with the Tm‐BiVO4 photoanode, reducing interfacial transfer resistance, but also expedite the kinetics of the water oxidation reaction. The profound significance of this work is that it offers a reference for the future design and fabrication of novel integrated photoanodes.

Rapid analysis of untreated food samples by gel loading tip spray ionization mass spectrometry.

Rapid, efficient, versatile, easy-to-use, and non-expensive analytical approaches are globally demanded for food analysis. Many ambient ionization approaches based on electrospray ionization (ESI) have been developed recently for the rapid molecular characterization of food products. However, those approaches mainly suffer from insufficient signal duration for comprehensive chemical characterization by tandem MS analysis. Here, a commercially available disposable gel loading tip is used as a low-cost emitter for the direct ionization of untreated food samples. The most important advantages of our approach include high stability, and durability of the signal (> 10min), low cost (ca. 0.1 USD per run), low sample and solvent consumption, prevention of tip clogging and discharge, operational simplicity, and potential for automation. Quantitative analysis of sulfapyridine, HMF (hydroxymethylfurfural), and chloramphenicol in real sample shows the limit-of-detection 0.1μgmL-1, 0.005μgmL-1, 0.01μgmL-1; the linearity range 0.1-5μgmL-1, 0.005-0.25μgmL-1, 0.01-1μgmL-1; and the linear fits R2 ≥ 0.980, 0.991, 0.986. Moreover, we show that tip-ESI can also afford sequential molecular ionization of untreated viscous samples, which is difficult to achieve by conventional ESI. We conclude that tip-ESI-MS is a versatile analytical approach for the rapid chemical analysis of untreated food samples.

Rapid analysis of untreated food samples by gel loading tip spray ionization mass spectrometry.

Rapid, efficient, versatile, easy-to-use, and non-expensive analytical approaches are globally demanded for food analysis. Many ambient ionization approaches based on electrospray ionization (ESI) have been developed recently for the rapid molecular characterization of food products. However, those approaches mainly suffer from insufficient signal duration for comprehensive chemical characterization by tandem MS analysis. Here, a commercially available disposable gel loading tip is used as a low-cost emitter for the direct ionization of untreated food samples. The most important advantages of our approach include high stability, and durability of the signal (> 10min), low cost (ca. 0.1 USD per run), low sample and solvent consumption, prevention of tip clogging and discharge, operational simplicity, and potential for automation. Quantitative analysis of sulfapyridine, HMF (hydroxymethylfurfural), and chloramphenicol in real sample shows the limit-of-detection 0.1μgmL-1, 0.005μgmL-1, 0.01μgmL-1; the linearity range 0.1-5μgmL-1, 0.005-0.25μgmL-1, 0.01-1μgmL-1; and the linear fits R2 ≥ 0.980, 0.991, 0.986. Moreover, we show that tip-ESI can also afford sequential molecular ionization of untreated viscous samples, which is difficult to achieve by conventional ESI. We conclude that tip-ESI-MS is a versatile analytical approach for the rapid chemical analysis of untreated food samples.