Use of waste frying oil and coconut pulp for the production, isolation, and characterization of a new lipase from Moesziomyces aphidis.

Lipases comprise the third most commercialized group of enzymes worldwide and those of microbial origin are sought for their multiple advantages. Agro-industrial waste can be an alternative culture medium for producing lipases, reducing production costs and the improper disposal of waste frying oil (WFO). This study aimed to produce yeast lipases through submerged fermentation (SF) using domestic edible oil waste as inducer and alternative culture medium. The optimal culture conditions, most effective inducer, and purification method for a new lipase from Moesziomyces aphidis BRT57 were identified. Yeast was cultured in medium containing green coconut pulp and WFO waste for 72 h. The maximum production of lipases in SF occurred in a culture medium containing WFO and yeast extract at 48 and 72 h of incubation, with enzyme activities of 8.88 and 11.39 U mL-1, respectively. The lipase was isolated through ultrafiltration followed by size exclusion chromatography, achieving a 50.46 % recovery rate. To the best of our knowledge, this is the first study to report the production and purification of lipases from M. aphidis, demonstrating the value of frying oil as inducer and alternative medium for SF, contributing to the production of fatty acids for biodiesel from food waste.

Zhongfeng decoction attenuates cerebral ischemia-reperfusion injury by inhibiting autophagy via regulating the AGE-RAGE signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Tackling phlegm and improving blood circulation is vital in the treatment of ischemic stroke (IS), culminating in the development of Zhongfeng Decoction (ZFD), a method grounded in this approach and serving as an effective therapy for IS. Nonetheless, the defensive mechanism of the ZFD in preventing cerebral ischemia-reperfusion damage remains ambiguous. AIM OF THE STUDY: Determine the active ingredients in ZFD that have neuroprotective effects, and identify its mechanism of action against IS. MATERIALS AND METHODS: A cerebral ischemia model in rats was developed, utilizing TTC, Nissl staining, and an oxidative stress kit to evaluate the neuroprotective impact of ZFD on this rat model. Following this, an amalgamation of LC-MS and network pharmacology techniques was employed to pinpoint potential active components, primary targets, and crucial action mechanisms of ZFD in treating IS. Finally, key targets and signaling pathways were detected using qRT-PCR, ELISA, Western blotting, electron microscopy, and other methods. RESULTS: Through LC-MS and network analysis, 15 active ingredients and 6 hub targets were identified from ZFD. Analysis of pathway enrichment revealed that ZFD predominantly engages in the AGE-RAGE signaling route. Kaempferol, quercetin, luteolin, baicalein, and nobiletin in ZFD are the main active ingredients for treating IS. In vivo validation showed that ZFD can improve nerve damage in cerebral ischemic rats, reduce the mRNA expression of IL6, SERPINE1, CCL2, and TGFB1 related to inflammation. Furthermore, we also confirmed that ZFD can inhibit the protein expression of AGEs, RAGE, p-IKBα/IKBα, p-NF-κB p65/NF-κB p65, reduce autophagy levels, and thus decrease neuronal apoptosis. CONCLUSIONS: The mechanism of action of ZFD in treating IS primarily includes inflammation suppression, oxidative stress response alleviation, post-stroke cell autophagy and apoptosis regulation, and potential mediation of the AGE-RAGE signaling pathway. This study elucidates how ZFD functions in treating IS, establishing a theoretical basis for its clinical application.

Removal and monitoring of residual nucleic acids from core streptavidin inclusion bodies for increased refolding yield.

Commercial production of recombinant streptavidin (SAV) using soluble expression route is cost-prohibitive, resulting from its inherent toxicity toward commercially available Escherichia coli hosts (such as BL21) and low productivity of existing manufacturing processes. Quality challenges can also result from binding of streptavidin in the host cells. One way to overcome these challenges is to allow formation of inclusion bodies (IBs). Nevertheless, carried-over cellular contaminants during IBs preparation can hinder protein refolding and application of SAV in nucleic acid-based applications. Hence, removing associated contaminants in recombinant IBs is imperative for maximum product outcomes. In this study, the IBs isolation method from our group was improved to remove residual DNA found in refolded core SAV (cSAV). The improvements were attained by incorporating quantitative real-time polymerase chain reactions (qPCR) for residual DNA monitoring. We attained 99 % cellular DNA removal from cSAV IBs via additional wash and sonication steps, and the addition of benzonase nuclease during lysis. A 10 % increment of cSAV refolding yield (72 %) and 83 % reduction of residual DNA from refolding of 1 mg cSAV IBs were observed under extensive sonication. Refolding of cSAV was not affected and its activity was not compromised. The optimized process reported here highlights the importance of obtaining cSAV IBs with minimal contaminants prior to refolding to increase product yield, and the usefulness of the qPCR method to monitor nucleic acid removed from each step of the process.

Vibrational spectroscopy of interstellar PAHs: 1-cyanonaphthalene and 2-cyanonaphthalene.

In this work, we present a comprehensive experimental and theoretical study of the vibrational spectra of PAH molecules recently detected in the interstellar medium: 1-cyanonaphthalene and 2-cyanonaphthalene. The room temperature IR spectra of 1- and 2-cyanonaphthalene in the region 100-3100 cm-1 and their vibrational Raman spectra in the region 35-3100 cm-1 are reported here for the first time. A detailed spectral analysis is carried out using quantum chemical calculations employing the DFT methodology. Anharmonic corrections using the VPT2 method yield excellent agreement with the experimental spectra. A re-investigation of the vibrational spectrum of the parent molecule: naphthalene validates the experimental and theoretical methods used. A consistent set of assignments is reported for the fundamental bands of 1- and 2-cyanonapththalene. The experimental and theoretical data presented here would be useful inputs for modelling the role of cyanonaphthalene in astrophysical processes.

An affordable, field-deployable detecting system for cyanide ion - Investigating applications in real time uses.

A highly efficient system that incorporates the instantaneous visualization of the cyanide ion in water was synthesized by keeping the fluorophore system (electron donor) as a julolidine-coumarin conjugate and changing the electron acceptor unit. The probes exhibit a notable color change in normal and UV light. The probe interaction modalities are based on the ICT process. With a detection limit in the nM range, it may preferentially react with cyanide, which is less than the tolerable level of 1.9 µM. According to 1H NMR data, the probes detect cyanide ions by nucleophilic addition reaction mechanism. Furthermore, current probe successfully determines real resources, including cyanide containing cassava powder, sprouted potatoes and various water samples. Besides the test strips, an electronic Arduino device was also employed to detect the cyanide ion. As such, the developed probes exhibit outstanding practical application with respect to the cyanide ion.

Glutathione and its structural modifications recognized by Raman Optical Activity and Circularly Polarized Luminescence.

Raman Optical Activity combined with Circularly Polarized Luminescence (ROA-CPL) was used in the spectral recognition of glutathione peptide (GSH) and its model post-translational modifications (PTMs). We demonstrate the potential of ROA spectroscopy and CPL probes (EuCl3, Na3[Eu(DPA)3], NaEuEDTA) in the study of unmodified peptide, i.e. GSH, and its derivatives, i.e. glutathione oxidized (GSSG), S-acetylglutathione (GSAc) and S-nitrosoglutathione (GSNO). ROA spectral features of GSH, GSSG, and GSAc were determined along with thier changes upon the different pH conditions. Apart from the ROA, induced CPL signals of Eu(III) probes also proved to be sensitive to the structural modifications of GSH-based model PTMs, enabling their spectral recognition, especially by the NaEuEDTA probe.

A novel fluorescent probe with high sensitivity and selectivity for "On-Off-On" sensors for Cu2+ cations and CN- anions.

A novel fluorescent probe NIPF was synthesized by the Suzuki reaction to recognize Cu2+ and CN-. With the addition of Cu2+, NIPF exhibited strong fluorescence quenching (90 % for NIPF) with a Ksv value of 3.4 × 106 M-1 and a detection limit of 9.04 × 10-10 M. Subsequently, CN- was added to the NIPF-Cu2+ solution, and [Cu(CN)x]n- was formed due to the strong interaction between Cu2+ and CN- leading to fluorescence recovery (89 % for NIPF-Cu2+). In addition, a detection limit of 3.6 × 10-8 M was obtained by fluorescence titration. Meanwhile, it was demonstrated that the sensor achieved 93 %-105 % recovery of Cu2+ in the tested environmental samples, and the practicability of Cu2+ and CN- detection were verified using hydrogels test, with significant color changes observed under 365 nm light. Accordingly, the fluorescent probe NIPF was used to recognize Cu2+ and CN- by the "on-off-on" sensors.

Warm red light emitting Eu(III) complexes synthesis and analysis including computational methods for photonic applications.

Six luminescent europium organic complexes have been synthesized and studied for their luminescent properties. The synthesized complexes were analyzed through elemental analysis, XRD, SEM, EDAX, FT-IR, NMR and thermogravimetry. The complexes exhibit crystalline behavior and possess decent thermal stability. Photoluminescence study on complexes were conducted in both solid and solution states, the results indicate the characteristic red emission. With the addition of ancillary ligands, water molecules are replaced from inner coordination sphere, leading to enhanced luminescence properties. The colorimetric parameters (CIE, CP%, CCT, u', v') suggest aptness of these complexes in red light illuminating OLEDs. The J-O parameters were calculated experimentally and theoretically with the help of LUMPAC software. Theoretical and experimental results agree well reflecting the efficacy of the outcomes. As a result of red emission, these complexes could have interesting photonics applications. The biological studies indicate the probable use of these complexes in the medical industry.

Tubeimoside-I, an inhibitor of HSPD1, enhances cytotoxicity of oxaliplatin by activating ER stress and MAPK signaling pathways in colorectal cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Tubeimoside-I (TBM) promotes various cancer cell death by increasing the reactive oxygen species (ROS) production. However, the specific molecular mechanisms of TBM and its impact on oxaliplatin-mediated anti-CRC activity are not yet fully understood. AIM OF THE STUDY: To elucidate the therapeutic effect and underlying molecular mechanism of TBM on oxaliplatin-mediated anti-CRC activity. MATERIALS AND METHODS: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, wound healing assays and flow cytometry were conducted to investigate the changes in cell phenotypes and ROS generation. Real-time quantitative PCR (qRT-PCR) and western blotting were performed to detect the expressions of related mRNA and proteins. Finally, mouse xenograft models demonstrated that synergistic anti-tumor effects of combined treatment with TBM and oxaliplatin. RESULTS: The synergistic enhancement of the anti-tumor effects of oxaliplatin in colon cancer cells by TBM involved in the regulation of ROS-mediated endoplasmic reticulum (ER) stress, C-jun-amino-terminal kinase (JNK), and p38 MAPK signaling pathways. Mechanistically, TBM increased ROS generation in colon cancer cells by inhibiting heat shock protein 60 (HSPD1) expression. Knocking down HSPD1 increased TBM-induced antitumor activity and ROS generation in colon cancer cells. The mouse xenograft tumor models further validated that the combination therapy exhibited stronger anti-tumor effects than monotherapy alone. CONCLUSIONS: Combined therapy with TBM and oxaliplatin might be an effective therapeutic strategy for some CRC patients.

Identification of Senkyunolide I as a novel modulator of hepatic steatosis and PPARα signaling in zebrafish and hamster models.

ETHNOPHARMACOLOGICAL RELEVANCE: Non-alcoholic fatty liver disease (NAFLD) is the leading cause of liver-related morbidity and mortality, with hepatic steatosis being the hallmark symptom. Salvia miltiorrhiza Bunge (Smil, Dan-Shen) and Ligusticum striatum DC (Lstr, Chuan-Xiong) are commonly used to treat cardiovascular diseases and have the potential to regulate lipid metabolism. However, whether Smil/Lstr combo can be used to treat NAFLD and the mechanisms underlying its lipid-regulating properties remain unclear. PURPOSE: To assess the feasibility and reliability of a short-term high-fat diet (HFD) induced zebrafish model for evaluating hepatic steatosis phenotype and to investigate the liver lipid-lowering effects of Smil/Lstr, as well as its active components. METHODS: The phenotypic alterations of liver and multiple other organ systems were examined in the HFD zebrafish model using fluorescence imaging and histochemistry. The liver-specific lipid-lowering effects of Smil/Lstr combo were evaluated endogenously. The active molecules and functional mechanisms were further explored in zebrafish, human hepatocytes, and hamster models. RESULTS: In 5-day HFD zebrafish, significant lipid accumulation was detected in the blood vessels and the liver, as evidenced by increased staining with Oil Red O and fluorescent lipid probes. Hepatic hypertrophy was observed in the model, along with macrovesicular steatosis. Smil/Lstr combo administration effectively restored the lipid profile and alleviated hepatic hypertrophy in the HFD zebrafish. In oleic-acid stimulated hepatocytes, Smil/Lstr combo markedly reduced lipid accumulation and cell damage. Subsequently, based on zebrafish phenotypic screening, the natural phthalide senkyunolide I (SEI) was identified as a major molecule mediating the lipid-lowering activities of Smil/Lstr combo in the liver. Moreover, SEI upregulated the expression of the lipid metabolism regulator PPARα and downregulated fatty acid translocase CD36, while a PPARα antagonist sufficiently blocked the regulatory effect of SEI on hepatic steatosis. Finally, the roles of SEI on hepatic lipid accumulation and PPARα signaling were further verified in the hamster model. CONCLUSIONS: We proposed a zebrafish-based screening strategy for modulators of hepatic steatosis and discovered the regulatory roles of Smil/Lstr combo and its component SEI on liver lipid accumulation and PPARα signaling, suggesting their potential value as novel candidates for NAFLD treatment.

Integration of network pharmacology, UHPLC-Q exactive orbitrap HRMS technique and metabolomics to elucidate the active ingredients and mechanisms of compound danshen pills in treating hypercholesterolemic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Hypercholesterolemia (HLC) was a key risk factor for cardiovascular disease (CVD) characterized by elevated cholesterol levels, particularly LDL. While traditional Chinese medicine preparations Compound Danshen Pills(CDP) has been clinically used for hypercholesterolemia and coronary heart disease, its specific therapeutic effect on HLC remains understudied, necessitating further investigation into its mechanisms. AIM OF THE STUDY: The aim of this study was to explore the potential of CDP in treating HLC and elucidate its underlying mechanisms and active components. MATERIALS AND METHODS: A hypercholesterolemic lipemia rat model induced by a high-fat diet was employed. Network pharmacology combined with UHPLC-Q exactive orbitrap HRMS technique was used to predict the active components, targets and mechanisms of CDP for HLC. Histological analysis and serum biochemical assays were used to assess the therapeutic effect of CDP and its main active ingredient Sa B on hypercholesterolemic lipemia rat model. Immunofluorescence assays and western blotting were used to verify the mechanism of CDP and Sa B in the treatment of HLC. Metabolomics approach was used to demonstrate that CDP and Sa B affected the metabolic profile of HLC. RESULTS: Our findings demonstrated that both CDP and its main active ingredient Sa B significantly ameliorated hypercholesterolemic lipemic lesions, reducing levels of TC, LDL, AST, ALT, and ALP. Histological analysis revealed a decrease in lipid droplet accumulation and collagen fiber deposition in the liver, as well as reduced collagen fiber deposition in the aorta. Network pharmacology predicted potential targets such as PPARα and CYP27A1. Immunofluorescence assays and western blotting confirmed that CDP and Sa B upregulated the expression of Adipor1, PPARα and CYP27A1. Metabolomics analyses further indicated improvements in ABC transporters metabolic pathways, with differential metabolites such as riboflavin, taurine, and choline showed regression in levels after CDP treatment and riboflavin, L-Threonine, Thiamine, L-Leucine, and Adenosine showed improved expression after Sa B treatment. CONCLUSION: CDP and Sa B have been shown to alleviate high-fat diet-induced hypercholesterolemia by activating the PPAR pathway and improving hepatic lipid metabolism. Our study demonstrated, for the first time, the complex mechanism of CDP, Sa B in the treatment of hypercholesterolemia at the protein and metabolic levels and provided a new reference that could elucidate the pharmacological effects of traditional Chinese medicine on hypercholesterolemia from multiple perspectives.

Label-free detection of kidney stones urine combined with SERS and multivariate statistical algorithm.

Kidney stones are a common urological disease with an increasing incidence worldwide. Traditional diagnostic methods for kidney stones are relatively complex and time-consuming, thus necessitating the development of a quicker and simpler diagnostic approach. This study investigates the clinical screening of kidney stones using Surface-Enhanced Raman Scattering (SERS) technology combined with multivariate statistical algorithms, comparing the classification performance of three algorithms (PCA-LDA, PCA-LR, PCA-SVM). Urine samples from 32 kidney stone patients, 30 patients with other urinary stones, and 36 healthy individuals were analyzed. SERS spectra data were collected in the range of 450-1800 cm-1 and analyzed. The results showed that the PCA-SVM algorithm had the highest classification accuracy, with 92.9 % for distinguishing kidney stone patients from healthy individuals and 92 % for distinguishing kidney stone patients from those with other urinary stones. In comparison, the classification accuracy of PCA-LR and PCA-LDA was slightly lower. The findings indicate that SERS combined with PCA-SVM demonstrates excellent performance in the clinical screening of kidney stones and has potential for practical clinical application. Future research can further optimize SERS technology and algorithms to enhance their stability and accuracy, and expand the sample size to verify their applicability across different populations. Overall, this study provides a new method for the rapid diagnosis of kidney stones, which is expected to play an important role in clinical diagnostics.

A three-stage wavelength selection algorithm for near-infrared spectroscopy calibration.

The near-infrared spectral data is highly high dimensional and contains redundant information, it is necessary to identify the most representative characteristic wavelengths before modeling to improve model accuracy and reliability. At present, there are many methods for selecting the characteristic wavelengths of NIR spectroscopy, but the collinearity among wavelengths is still a main issue that leads to poor model effects. Therefore, this study proposes a three-stage wavelength selection algorithm (Stage III) to reduce redundancy in NIR spectral data and collinearity between wavelength variables, resulting in a simpler and more accurate predictive model. The research uses a public NIR data set of corn samples as its subject. Initially, the wavelengths with the higher correlation coefficients are chosen after calculating the relationship coefficients between every wavelength vector and the concentration vector. On this basis, the correlation coefficients between the vectors of each wavelength point are calculated, and those wavelength points with smaller correlation coefficients with other wavelength points are selected. Ultimately, the stepwise regression analysis selects the wavelengths that provide substantial value to the model as the variables for modeling, leading to the development of a multiple linear regression model. The results show that the model using the three-stage wavelength selection algorithm outperforms those using the full spectrum, Stages I and Stage II, and the coefficient of determination of the test set of the Stage III-MLR model achieved an accuracy of 0.9360. Instead of the successive projections algorithm (SPA), uninformative variable elimination (UVE), and competitive adaptive reweighted sampling (CARS), Stage III is better in the model prediction accuracy. Therefore, the three-stage wavelength selection algorithm is an effective wavelength selection algorithm that can effectively model NIR spectroscopy, reduce the collinearity between the wavelength variables, simplify the complexity of the model, and improve the prediction precision of the model.

Spectroscopic and nonlinear optical investigations of biscinnamyl-sulfone derivatives: Computational and experimental insights.

Novel geometrically asymmetric biscinnamyl-sulfone compounds (6a-c) with donor-π-conjugated spacer-acceptor functionality were successfully synthesized. This was achieved by coupling cinnamaldehyde precursors with 3,3'-diaminodiphenyl sulfone in dry organic solvents, resulting in high yields. Several spectroscopic techniques were employed to identify the derivatives. The absorption spectra of these compounds exhibited broad bands that spanned up to 120 nm, which can be attributed to their extended conjugation systems. In order to explore the electronic transitions of these materials, Time-Dependent Density-Functional Theory (TD-DFT) with EIFPCM solvation mode was utilized. We computationally investigated the static nonlinear optical (NLO) parameters, including dipole moments (µ), polarizability (α), anisotropic polarizability (Δα), first-order hyperpolarization (ß), and second-order hyperpolarization (γ). Although the new structures possess different functional groups, they displayed similar electronic potentials when their molecular electrostatic potentials were plotted. These potentials are crucial in stabilizing the molecules in crystal systems through noncovalent forces such as C-H⋯π stacking and hydrogen bonding. They also provide insights into the electronic assessments and energetics of these individual forces. By estimating the frontier orbitals, we gained an understanding of the intramolecular charge transfer in the compounds. Energy gap values were determined using the orbitals of density of states method and experimentally via the Tauc method. The computational and experimental results were in good agreement. Lastly, we examined the influence of different protic and aprotic solvents on the absorption bands of compound 6b, as an example. This compound showed a significant bathochromic shift of 41 nm upon changing the solvent from acetic acid to dimethyl sulfoxide.

A dual-channel fluorescent probe targeting lysosomes for differential detection of Cys/Hcy and GSH: Applications in food, pharmaceutical analysis and bioimaging.

Thiols function as antioxidants in food, prolonging shelf life and enhancing flavor. Moreover, thiols are vital biomolecules involved in enzyme activity, cellular signal transduction, and protein folding among critical biological processes. In this paper, the fluorescent probe PYL-NBD was designed and synthesized, which utilized the fluorescent molecule pyrazoline, the lysosome-targeted morpholine moiety, and the sensing moiety NBD. Probe PYL-NBD was tailored for the recognition of biothiols through single-wavelength excitation, yielding distinct fluorescence emission signals: blue for Cys, Hcy, and GSH; green for Cys, Hcy. Probe PYL-NBD exhibited rapid reaction kinetics (<10 min), distinct fluorescence response signals, and low detection limits (15.7 nM for Cys, 14.4 nM for Hcy, and 12.6 nM for GSH). Probe PYL-NBD enabled quantitative determination of Cys content in food samples and L-cysteine capsules. Furthermore, probe PYL-NBD had been successfully applied for confocal imaging with dual-channel detection of biothiols in various biological specimens, including HeLa cells, zebrafish, tumor sections, and Arabidopsis thaliana.

Study on the underlying mechanism of Huachansu Capsule induced cardiotoxicity of normal rat by integrating transcriptomics, metabolomics and network toxicology.

ETHNOPHARMACOLOGICAL RELEVANCE: Huachansu Capsule (HCSc) is a simple enteric-coated capsule refined from the skin of the dried toad, a traditional medicinal herb. It has been used clinically for many years to treat a variety of malignant tumors with remarkable efficacy. To date, a number of main components of HCSc have been reported to be cardiotoxic, but the specific mechanism of cardiotoxicity is still unknown. AIM OF THE STUDY: The aim of this study was to elucidate the possible cardiotoxic symptoms caused by high-doses of HCSc and to further reveal the complex mechanisms by which it causes cardiotoxicity. MATERIALS AND METHODS: UPLC-Q-Exactive Orbitrap MS and network toxicology were used to identify and predict the potential toxic components, related signaling pathways. Then, we used acute and sub-acute toxicity experiments to reveal the apparent phenomenon of HCSc-induced cardiotoxicity. Finally, we combined transcriptomics and metabolomics to elucidate the potential mechanism of action, and verified the putative mechanism by molecular docking, RT-qPCR, and Western blot. RESULTS: We found 8 toad bufadienolides components may be induced cardiac toxicity HCSc main toxic components. Through toxicity experiments, we found that high dose of HCSc could increase a variety of blood routine indexes, five cardiac enzymes, heart failure indexes (BNP), troponin (cTnI and cTnT), heart rate and the degree of heart tissue damage, while low-dose of HCSc had no such changes. In addition, by molecular docking, found that 8 kinds of main toxic components and cAMP, AMPK, IL1ß, mTOR all can be a very good combination, especially in the cAMP. Meanwhile, RT-qPCR and Western blot results showed that HCSc could induce cardiotoxicity by regulating a variety of heart-related differential genes and activating the cAMP signaling pathway. CONCLUSIONS: In this study, network toxicology, transcriptomics and metabolomics were used to elucidate the complex mechanism of possible cardiotoxicity induced by high-dose HCSc. Animal experiments, molecular docking, Western blot and RT-qPCR experiments were also used to verify the above mechanism. These findings will inform further mechanistic studies and provide theoretical support for its safe clinical application.

Toward understanding ammonia capture in two amino-functionalized metal-organic frameworks using in-situ infrared spectroscopy and DFT calculation.

Two isostructural, three-dimensional, interpenetrated amino-functionalized Metal-Organic Frameworks (Co-2AIN-MOF and Cd-2AIN-MOF) based on 2-aminoisonicotinic acid (2AIN) were synthesized, structurally characterized and determined. Based on the PXRD analysis, the solvent exchange hardly changed their framework structure, and the samples fully activated by methanol can be achieved and examined by infrared spectroscopy. Due to the presence of the carbonyl group and free amino groups in the pore of the framework, the NH3 uptakes of Co-2AIN-MOF and Cd-2AIN-MOF are 11.70 and 13.81 mmol/g and at 1 bar, respectively. In-situ Infrared spectroscopy and DFT calculations revealed the different adsorption sites and processes between Co-2AIN-MOF and Cd-2AIN-MOF.

Effect of structure on sensing performance of nitro explosives with high sensitivity and mechanism of two Tb(III) coordination polymers.

The use of a conjugate N-containing ligand resulted in the decreasing of structural dimensions from 2D network of [Tb(2-pyia)(Ac)(H2O)] (CP1) to 1D chain [Tb(2-pyia)(Ac)(IDP)] (CP2) (2-H2pyia = 5-(pyridin-2-ylmethoxy) isophthalic acid and IDP=imidazo[4,5-f]-[1,10] phenanthroline). Both of them exhibit the characteristic luminescence of Tb ions and could have high fluorescence sensing properties for cefixime and fluridine. The different sensing properties for nitro explosives are manifested as CP1 for nitrobenzene and CP2 for 4-nitrophenol due to the difference in structure. Furthermore, CP2 exhibits the ratiometric fluorescence sensing for Fe3+ ion with a low detection limit of 0.405 µM. The fluorescence sensing mechanism of the two Tb complexes for different analytes was investigated using experimental methods and theoretical calculations. CP1 was used for the detection of Flu residues in the actual system and better results were obtained. The work shows the introduction of the chelated ligand might affect the structural and sensing performance changes of coordination polymers.

Cu,Ce-containing phosphotungstates as laccase-like nanozyme for colorimetric detection of Cr(VI) and Fe(â ¢).

Herein, a nanocomposite of Cu,Ce-containing phosphotungstates (Cu,Ce-PTs) with outstanding laccase-like activity was fabricated via a one-pot microwave-assisted hydrothermal method. Notably, it was discovered that both Fe3+ and Cr6+ could significantly enhance the electron transfer rates of Ce3+ and Ce4+, along with generous Cu2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe3+ and Cr6+ in a range of 0.667-333.33 µg/mL and 0.033-33.33 µg/mL with a low detection limit of 0.135 µg/mL and 0.0288 µg/mL, respectively. The proposed assay exhibits excellent reusability and selectivity and can be used in traditional Chinese medicine samples analysis.

Highly selective and visual detection of vanillin based on fluorescence Cd-MOF sensor in milk powders.

Vanillin is a commonly used synthetic flavoring agent in daily life. However, excessive intake of vanillin may pose risks to human health. Therefore, there is an urgent need for rapid and sensitive detection methods for vanillin. In this study, we developed a fluorescent sensor based on Cd-MOF for the sensitive and selective recognition of vanillin. The presence of vanillin leads to significant fluorescence quenching of Cd-MOF due to competitive absorption and photoinduced electron transfer (PET). The limit of detection was determined to be 39.6 nM, which is the lowest-among the reported fluorescent probes. The sensor was successfully applied for the detection of vanillin in real samples such as powdered milk and milk, with a recovery rate ranging from 96.88 % to 104.83 %. Furthermore, by immobilizing the Cd-MOF probe into a polyvinyl alcohol (PVA) film, we achieved a portable and visual detection composite materials for vanillin.