Oxalic Acid Research Articles

Engineering Yarrowia lipolytica to Produce l-Malic Acid from Glycerol.

The declining availability of cheap fossil-based resources has sparked growing interest in the sustainable biosynthesis of organic acids. l-Malic acid, a crucial four-carbon dicarboxylic acid, finds extensive applications in the food, chemical, and pharmaceutical industries. Synthetic biology and metabolic engineering have enabled the efficient microbial production of l-malic acid, albeit not in Yarrowia lipolytica, an important industrial microorganism. The present study aimed to explore the potential of this fungal species for the production of l-malic acid. First, endogenous biosynthetic genes and heterologous transporter genes were overexpressed in Y. lipolytica to identify bottlenecks in the l-malic acid biosynthesis pathway grown on glycerol. Second, overexpression of isocitrate lyase, malate synthase, and malate dehydrogenase in the glyoxylate cycle pathway and introduction of a malate transporter from Schizosaccharomyces pombe significantly boosted l-malic acid production, which reached 27.0 g/L. A subsequent increase to 37.0 g/L was attained through shake flask medium optimization. Third, adaptive laboratory evolution allowed the engineered strain Po1g-CEE2+Sp to tolerate a lower pH and to accumulate a higher amount of l-malic acid (56.0 g/L). Finally, when scaling up to a 5 L bioreactor, a titer of 112.5 g/L was attained. In conclusion, this study demonstrates for the first time the successful production of l-malic acid in Y. lipolytica by combining metabolic engineering and laboratory evolution, paving the way for large-scale sustainable biosynthesis of this and other organic acids.

Optimization of Plant Oxalate Quantification and Generation of Low-Oxalate Maize (Zea mays L.) through O7 Overexpression

Oxalate, the simplest dicarboxylic acid, is a prevalent antinutrient that chelates with various metals and can lead to the formation of kidney stones in humans. The accurate detection of the oxalate concentration in food and the cultivation of low-oxalate crops are important for enhancing public health. In this study, we established a high-throughput and highly sensitive technique for oxalate detection using ultra-high-performance liquid chromatographic–triple quadrupole tandem mass spectrometry (UPLC-QqQ-MS/MS). Additionally, we overexpressed the gene O7, which encodes oxalyl-CoA synthetase in the maize oxalate degradation pathway, resulting in O7-OE lines. By employing the UPLC-QqQ-MS/MS method to measure oxalate levels in these transgenic lines, we observed that the oxalate content in the kernels of O7-OE lines was reduced by approximately 43%, with a concurrent increase in some micronutrients such as zinc. Importantly, the transgenic maize showed normal seed storage compound accumulation or other agronomic characteristics. In summary, we developed a high-throughput detection method that advances oxalate measurement. Furthermore, by generating new maize germplasm with diminished oxalate, our work offers potential health advantages to consumers.

Light-Sheet Skew Ray-Based Microbubble Chemical Sensor for Pb2+ Measurements

A multimode fiber-based sensor is proposed and demonstrated for the detection of lead traces in contaminated water. The sensing mechanism involves using a light sheet to excite a specific group of skew rays that optimizes light absorption. The sensing region features an inline microbubble structure that funnels the skew rays into a tight ring, thereby intensifying the evanescent field. The sensitivity is further refined by incorporating gold nanoparticles, which amplify the evanescent field strength through localized surface plasmon resonance. The gold nanoparticles are functionalized with oxalic acid to improve specificity for lead ion detection. Experiment results demonstrated the significantly enhanced absorption sensitivity of the proposed sensing method for large center offsets, achieving a detection limit of 0.1305 ng/mL (the World Health Organization safety limit is 10 ng/mL) for concentrations ranging from 0.1 to 10 ng/mL.

Maize-Straw Biochar Enhances Soil Properties and Grain Yield of Foxtail Millet in a Newly Reclaimed Land

Large-scale land reclamation has become common in northwestern China; however, low soil fertility and poor soil water-holding capacity limit agricultural production on these reclaimed lands, requiring increased fertilizer and irrigation inputs. Biochar, produced from agricultural waste, has shown potential in improving soil quality and water-holding capacity. In this two-year field study (2021 and 2022), we investigated the effects of biochar produced from maize straw on soil properties and grain yield of foxtail millet grown on newly reclaimed land. Three biochar treatments (3000, 4500, and 6000 kg ha−1) were compared to a control (CK) with no biochar application. Biochar application resulted in increased soil organic matter, total phosphorus, total nitrogen, soil enzyme activity, and soil organic acid content. It also significantly decreased soil pH and bulk density. Compared with the CK, biochar increased available nitrogen from 29.7% to 108% in 2021 and 37.0% to 88.4% in 2022. Similarly, biochar increased available phosphorus from 64.7% to 143% in 2021 and 41.9% to 96.5% in 2022. Grain yields ranged from 3092 to 4753 kg ha−1. Biochar treatments increased grain yield compared to the CK, ranging from 12.2% to 24.6% in 2021 and 27.1% to 53.7% in 2022. Correlation analysis revealed that soil pH was negatively related to soil oxalic acid content, phosphorus content, and sucrase activity. Available nitrogen and phosphorus contents were negatively related to soil bulk density and positively related to catalase activity. Soil water content was negatively correlated with soil bulk density and positively correlated with organic matter. In conclusion, biochar improved the rhizosphere soil pH and the effectiveness of soil fertility in the newly reclaimed soil, resulting in an enhanced grain yield of foxtail millet.

Palladium-Catalyzed One-Pot Synthesis of N-Formylaniline Derivatives Using Oxalic Acid as a Dual Carbon Monoxide and Hydrogen Donor.

A palladium-catalyzed three-component reaction enabled the synthesis of N-formylanilines from aryl iodides, NaN3, and oxalic acid. This one-pot process involves aminocarbonylation, the Curtius rearrangement, and reduction using oxalic acid as both a carbon monoxide and hydrogen donor. The method has a broad substrate scope, tolerates various functional groups, and delivers N-formylanilines in high yields, making it a green and useful synthetic approach.

Osmolytes and CsAQP expression jointly influence water physiology in the peel and pulp of orange (Citrus sinensis (L.) Osbeck) fruit during postharvest water loss

Water loss is a serious issue affecting the quality of postharvest horticultural products. Aquaporins (AQPs) regulate the transport of water across biological membranes, along the gradient of water potential, and may play a role in water loss. In this study, matured orange fruits (Citrus sinensis) stored at ambinent temperature (RH 85-95%) for 105 d showed that the weight loss persistently increased, and its rate peaked at 45–60 d and 90–105 d. Both water content and potential were higher in the pulp than in the peel. Water content rose before 60 d, and peel water potential fell with an increased gradient after 60 d. Comparing with peel, osmolytes such as soluble sugar, sucrose, glucose, fructose, and organic acids showed higher accumulation, and their levels were the lowest around 60 d. In contrast, soluble protein and inorganic minerals showed low levels of accumulation in the pulp. In total, 31 CsAQP genes were expressed in the fruit, and most of them were down-regulated in the peel but up-regulated in the pulp during storage. These genes were subsequently classified into four clusters based on their expression patterns. Genes in Cluster I — including CsNIP1;1/2;1/2;2/2;3/3;1/4;1/6;1, CsTIP1;3/2;2/2;3/5;1/6;1, CsXIP1;1/1;2, CsSIP1;2, and CsPIP1;2 — were persistently up-regulated in the pulp for the 105 d of storage, especially at day 60, when some genes showed 103-fold higher expression. Pearson’s correlation and principal component analysis further revealed a significant positive correlation among weight loss rate, water content, and water potential gradient (R2 = 0.85). Indexes positively correlated with osmolyte content and Cluster I gene expression in pulp samples suggest that increased CsAQP gene expression in pulp is linked to faster water loss in oranges, particularly at 60 days postharvest.

Melt Polycondensation Strategy to Access Unexplored l-Amino Acid and Sugar Copolymers.

Biodegradable polymers from bioresources are highly in demand for the development of sustainable polymer platforms for commodity plastics and in the biomedical field. Here, an elegant one-pot synthetic strategy is developed, for the first time, to access unexplored hybrid polymers from two naturally abundant resources: carbohydrates (sugars) and l-amino acids. A bottleneck in the synthetic strategy is overcome by tailor-making d-mannitol-based six- and five-membered bicyclic acetalized diols, and their structures are confirmed by single-crystal X-ray diffraction and 2D NMR spectroscopy. l-Amino acids are converted into ester-urethane functional monomers, and they are polymerized with sugar-diols under solvent-free melt polycondensation to yield biodegradable poly(ester-urethane)s. Acid-catalyzed deprotection yielded amphiphilic polymers having exclusively alternating residues of sugar and l-amino acid in the polymer backbone. The polymer is self-assembled into 200 ± 10 nm sized nanoparticles that can encapsulate fluorescent dyes, are nontoxic to cells up to 250 μg/mL, and are readily endocytosed for lysosomal enzymatic biodegradation at the cellular level.

Investigation on induced smectic phases in double hydrogen bond liquid crystal complexes derived from aromatic carboxylic acids: Experimental and quantum chemical approaches

In the present study, double Hydrogen bond liquid crystal (HBLC) complexes in different mole ratio (1:1 and 1:2) have been isolated from symmetrical aromatic dicarboxylic acid of non-mesogenic compound 1,3-Phenylenediacetic acid (1,3-PDA) and mesogenic compound 4-n-dodecyloxybenzoic acid (12 OBA). Fourier transform infrared Spectroscopy (FTIR) explores the presence of functional groups in the title complexes. Formation of H-bond between 1,3-PDA and 12 OBA is experimentally confirmed by observing the FTIR peak at 3639 cm−1 (1:1 ratio). Induced mesophases and its textures along with transition temperatures are analyzed using polarizing optical microscope (POM) and differential scanning calorimetry (DSC). The layered structures (smectic phases) and their molecular mechanism has been analyzed using density functional theory (DFT). Further, the establishment of H-bond in the title complex has been investigated with the aid of optimized geomentry, molecular electrostatic potential (MEP) and reduced density gradient (RDG) analysis. The band gap energy of title complex (1:1) is calculated by UV–Vis spectrometer and the same has been justified by HOMO-LUMO studies. Maximum absorption in the UV region and moderate bandgap energy (Eg = 4.22 eV) of the title complex clearly indicates its potential application in NLO, optoelectronics and laser tuning devices. In addition to that, LC parameters and its effect on mesophase are reported using experimental and computational methods.

Novel oxygen vacancies-rich 3D porous ZnO for highly sensitive 3-hydroxy-2-butanone biomarker gas sensors

Listeriosis can cause human death via infection by Listeria monocytogenes (LMs) with a high fatality rate of 20–30 %. Detection of 3-hydroxy-2-butanone (3H-2B) biomarker of LMs can achieve estimation of LMs content, which is of great significance for human health. Exploring porous metal oxide semiconductors (MOSs) with rich vacancies towards 3H-2B sensing is quite promising for achieving this goal. Herein, we report a highly sensitive 3H-2B sensor based on novel 3D porous ZnO with rich oxygen vacancies which was facilely obtained by sacrificing Zn foam in oxalic acid and subsequent thermal decomposition. The ZnO sensor displays ultrahigh sensor response of Ra/Rg = 328@5 ppm, super-low detection limit of 0.001 ppm, excellent cycling stability and selectivity and good linear response at 120 °C, showing great potential for precise detection of 3H-2B biomarker. The porous structure and increased oxygen vacancies contribute greatly to the adsorption of active oxygen species therefore the sensing reactions on ZnO surface, which accounts for the high sensing performance. Our work provides an ingenious strategy to produce novel 3D ZnO with rich oxygen vacancies as well as new insights for boosting the detection of LMs.

Preparation and thermal stability research of oxalic acid dihydrate-glutaric acid/PAMPS phase change gel for solar thermal energy utilization

Thermal energy storage technology based on phase change materials (PCMs) can address the temporal and spatial mismatches in solar thermal energy conversion, thereby enhancing solar energy utilization efficiency. However, the liquid flow and poor thermal reliability of PCMs limit their large-scale application in solar thermal systems. In this study, we employ a simple “one-pot method” to prepare a form-stable and thermally reliable oxalic acid dihydrate-glutaric acid/poly 2-Acrylamido-2-methyl-1-propanesulfonic acid (OAD-GA/PAMPS) phase change gel. The OAD-GA/PAMPS phase change gel melts at 64.5 °C with a phase change enthalpy of 193.6 kJ/kg, the tensile strength is 7.707 MPa, and the compressive strength is 16.940 MPa. By incorporating 5 wt% BN particles, the thermal conductivity of OAD-GA/PAMPS phase change gel reaches 0.63 W/(m·K). After 200 heating-cooling cycles, the phase change temperature of the OAD-GA/PAMPS phase change gel remains nearly unchanged, and the phase change enthalpy decreases by only 5.7 %. The photo-thermal conversion efficiency of the OAD-GA/PAMPS phase change gel is 82.7 %. The high thermal reliability and photo-thermal conversion efficiency of the OAD-GA/PAMPS phase change gel makes it suitable for solar thermal energy storage applications.

Binary and Ternary Deep Eutectic Solvents for Methylene Green Electropolymerization on Multiwalled Carbon Nanotubes: Optimization, Characterization and Application.

Choline chloride (ChCl) based binary and ternary deep eutectic solvents (DES) were evaluated for methylene green electropolymerization with oxalic acid (OA) and ethylene glycol (EG) as hydrogen bond donors. Binary DES ChCl : OA in molar ratios 1 : 1 and 2 : 1 and ChCl : EG 1 : 2 and ternary DES (tDES) in different molar ratios and percentages of water were evaluated. The highest polymer growth was in ChCl : OA : EG-tDES with 13% added water, that had a lower viscosity and higher ionic conductivity when associated with HCl as dopant. This enhanced the formation of more cation radicals and, consequently, more polymer formation. The PMG/MWCNT/GCE-tDES sensor was successfully applied to the simultaneous determination of 5-aminosalicylic acid (5-ASA) and acetaminophen (APAP) by differential pulse voltammetry in the concentration range 1 μM-200 μM, with detection limits of 0.37 μM and 0.49 μM for 5-ASA and APAP, respectively. The sensor demonstrated good repeatability, reproducibility and stability, and was successfully applied in pharmaceutical formulations.

Pyrazine Dicarboxylic Acid and Phosphite-Bridging Lanthanide-Incorporated Tellurotungstates and Their Fluorescence Performances.

Two pyrazine dicarboxylic acid and phosphite-bridging lanthanide-incorporated tellurotungstates [H2N(CH3)2]12 Na4[Ln4(H2O)2(H2PDBA)2(HPO3)2W6O10][B-α-TeW8O31]4 · 70H2O [Ln = Eu3+ (1), Tb3+ (2); H2PDBA = 2,5-pyrazine dicarboxylic acid) were prepared, which contain four [B-α-TeW8O31]10- subunits and a deca-nuclear heterometallic [Ln(H2O)2(HPO3)2 (H2PDBA)2(W3O5)2]24+ cluster. Strikingly, two H2PDBA ligands connect two equivalent {W3Eu2O5(H2O)(B-α-TeW8O31)2(HPIIIO3)}8- moieties to form the polyanion skeleton, while the phosphite plays a bridging role in joining two lanthanide centers in the {W3Eu2O5(H2O)(B-α-TeW8O31)2(HPIIIO3)}8- moiety. In addition to the fluorescence (FL) properties of 1 and 2 at room temperature, their temperature-dependent FL properties were also investigated. In 80-298 K, FL intensities of 1 and 2 decrease as temperature increases, and their maximum relative sensitivities (Sr) are 3.70 and 1.99% K-1, whereas the minimum temperature uncertainties (δT) are 1.25 and 1.18 K for 1 and 2. In 298-973 K, upon increasing temperature, FL intensities of 1 and 2 initially rise to their maxima at 373 K and subsequently decrease. This is because samples of 1 and 2 undergo dehydration together with amorphization below 473 K and decomposition above this temperature. This work lays a foundation for the development for luminescent thermometers based on lanthanide-incorporated polyoxometalates.

Novel Flavonol Derivatives Containing Quinoxaline: Insights into the Antifungal Mechanism against Sclerotinia sclerotiorum.

In this study, 12 pairs of tautomeric flavonol derivatives containing quinoxaline were synthesized. The results of antifungal activity showed that in the enol-keto tautomerism, the target compounds containing keto (YB series) had better inhibitory activity against Sclerotinia sclerotiorum (S.s.) than compounds containing enol (YA series). YB9 showed the strongest antifungal activity against S.s., and the median effective concentration (EC50) value was 1.0 μg/mL, which was better than azoxystrobin (Az, 35.3 μg/mL). In vivo fungal inhibition experiments showed that the protective activity of YB9 against rape leaves was 83.4% at 200 μg/mL, which was superior to that of Az (70.2%). The activity of succinate dehydrogenase and molecular docking results showed that YB9 had a stronger antifungal effect than YA9. The results of oxalic acid content determination showed that YB9 could reduce the pathogenic ability of S.s. Then, the inhibitory effect of YB9 against S.s. was further verified by scanning electron microscopy, fluorescence microscopy, cell membrane permeability, cell content leakage, and malondialdehyde content.

Multifaceted analyses reveal sugar and organic acid metabolism affecting the palatability in mulched Phyllostachys violascens shoots with varied sheath colors

The color of bamboo shoot sheaths influences both appearance and palatability in mulched Phyllostachys violascens shoots, but the mechanisms linking sheath color to flavor and texture are unclear. This study combined metabolomics and transcriptomics to investigate the relationship between sheath color and palatability, focusing on sugar and organic acid metabolism. We identified 5698 metabolites and 33 differentially expressed genes across bamboo shoots with different sheath colors. Darker shoots (black-brown, BSD) exhibited enhanced organic acids and flavor amino acid synthesis, contributing to moderate sweetness. In contrast, as the sheath color lightens (bright-red, BSM; yellow-green, BSL), sugar degradation and cell wall metabolism (e.g., lignin, pectin, cellulose) became more pronounced. BSL shoots, with the lightest sheath color, demonstrated reduced sugar degradation and increased synthesis of pectin and cellulose, resulting in greater sweetness and improved texture. These findings demonstrate that variations in sheath color are closely linked to metabolic shifts that influence both flavor and texture, offering valuable insights for targeted breeding programs aimed at enhancing bamboo shoot quality.

Production of Biopolymer & Preparation of Soap Using Chitin and Chitosan from Brachyura Shell

Collagen, an extracellular protein, was extracted from eggshells using a combination of 5% EDTA, 0.45 M NaCl, 0.2% NaOH, 0.2% H₂SO₄, 0.7% citric acid, and 10% HCl, while chitosan, a naturally occurring polysaccharide, was extracted from crab shells (Brachyura) through demineralization with 1N Hydrochloric acid, deproteinization using 6% sodium hydroxide solution, and deacetylation with 40% NaOH, followed by decolorization using potassium permanganate and oxalic acid. The proximate analysis of chitosan revealed an ash content of 32% and a moisture content of 4.13%, while the protein content of the extracted collagen was found to be 70 µg/dL, with an alternative method indicating 75 µg, equivalent to BSA. The molecular weights of collagen and chitosan were determined to be 300 kilodaltons and 190-310 kilodaltons, respectively, and their purity was confirmed using FTIR analysis. Hydrogels were prepared using a combination of collagen and chitosan and were tested for water absorption capacity and antimicrobial activity, demonstrating that both biomaterials possess significant antimicrobial and antioxidant properties. Additionally, chitosan’s biocompatibility supports its use in creating edible films that can interact with other biopolymers and additives, indicating its potential for various industrial and biomedical applications.

Chemical Composition and Insecticidal Potential of Essential Oil from Murraya koenigii (L.) Obtained by Natural Deep Eutectic Solvents.

Aphis craccivora Koch and Planococcus lilacinus Cockerell are phloem feeders and act as vectors for transmitting plant viruses to agricultural and horticultural crops thereby damaging them. The persistent and widespread use of synthetic, wide-spectrum pesticides has resulted in resistance development that is detrimental to the environment, human health, and natural enemies of pests. The present investigation uses various extraction mediums to examine the insecticidal efficacy of essential oils (EOs) isolated from Murraya koenigii (L.) leaves. Increase in yield was observed in the EO extracted using NADES-AHD [0.16% (obtained with hydro-distillation)] to 0.30% [obtained with N-1 (glycerol:lactic acid)]. EO obtained with water was found more effective against A. craccivora (LD50 = 0.89 µL/insect) and followed by N-1 (glycerol:lactic acid), and N-3 (choline chloride:citric acid) (LD50 = 1.29-1.38 µL/insect). Similarly, EO isolated by water and N-4 (choline chloride:oxalic acid) was effective against P. lilacinus (LD50 = 2.63-3.06 µL/insect). Additionally, the EO prepared by water substantially reduced glutathione S-transferase (GST) and acetylcholinesterase (AChE) in target pests, suggesting that these enzymes may be the EOs' site of action. NADES-AHD has enhanced the EO yield as compared to the conventional method. The EO obtained with water showed promising toxicity against target pests and target site of action. Therefore, based on field and greenhouse bio-efficacy experiments, EOs/biopesticides/botanicals can be proposed for controlling the spread of mealy bugs and aphids.

Enhancing Animal Nutritional Security Through Biofortification in Forage Crops: A Comprehensive Review

Livestock nutrition is crucial for sustaining the health and productivity of farm animals, which are a cornerstone of the global food supply. Proper nutrition ensures that animals receive the necessary nutrients for essential bodily functions, growth, reproduction and lactation. Tailored, balanced diets that cater to the specific nutritional needs of different livestock species and their developmental stages also boost reproductive performance, leading to higher birth rates and healthier offspring. Conversely, inadequate nutrition can lead to stunted growth, diminished productivity, and increased vulnerability to diseases, ultimately resulting in significant economic losses. Nutritional imbalances among animals, especially in dairy goats and cattle, pose a significant challenge in livestock management. These disorders result from inadequate or imbalanced nutrient intake, leading to a range of metabolic and health issues. Fodders are essential to livestock nutrition, providing a balanced diet that supports overall animal health, growth and productivity. They are primary sources of energy, with grasses and cereals supplying carbohydrates needed for maintenance and production activities. Leguminous fodders like alfalfa and clover are rich in protein and crucial for muscle development, milk production and growth. Additionally, green fodders offer vital vitamins (A, D, E, K) and minerals such as calcium and phosphorus, which are necessary for various metabolic functions. The high fibre content in fodders aids in proper digestion and prevents digestive disorders. Overall, the review highlights the impact of various nutrient deficiencies on livestock, including the effects of anti-nutritional factors and the mechanisms of nitrate, oxalate and prussic acid toxicity in animals. It underscores the importance of agronomic bio fortification as a promising strategy to enhance the nutritional quality of fodder crops, thereby improving animal health and welfare, while also contributing to food security and sustainable agriculture.

Cocrystal screening of benznidazole based on electronic transition, molecular reactivity, hydrogen bonding, and stability.

Screening of cocrystals of active pharmaceutical ingredients is important in the development of pharmaceutical compounds because it improves bioavailability, stability, solubility, and many other physicochemical properties. In this work, quantum chemical calculations were utilized for the computational evaluation of the cocrystal screening of benznidazole (BZN) API via hydrogen bonding with four coformers (maleic acid, malonic acid, oxalic acid, and salicylic acid), and they contain carboxylic groups. The nitrogen of the imidazole ring in benznidazole and the carboxylic group of the coformer form a hetero-synthon connected by a strong hydrogen bond. The strength of the hydrogen bonding interaction O-H…N was measured using various tools. It was found that in comparison to BZN cocrystals with malonic acid, oxalic acid, and salicylic acid, the O-H…N interaction in the BZN-maleic acid cocrystal had higher interaction energy, indicating it had stronger hydrogen bonding. The strength of the hydrogen bond O-H…N for synthons was discovered to be more beneficial than the C-H…O interaction, as confirmed by ESP analysis. The BZN-salicylic acid cocrystal was found to be more reactive and polarizable, whereas the BZN-malonic acid cocrystal was more stable. Cocrystals of benznidazole exhibited better physicochemical characteristics than API benznidazole, as indicated by electron transition properties between the most significant orbitals. The computational evaluation for the screening of benznidazole cocrystals was performed in Gaussian 16 software using density functional theory (DFT) with the hybrid functional B3LYP and the basis set 6-311 + + G(d,p). The UV-Vis absorption spectrum in solvent water was analyzed using the TD-DFT/6-311 + + G(d,p) method to determine the influence of the solvent in cocrystals using a polarizable continuum model. The strength of the hydrogen bonding interactions O-H…N in each of those mentioned cocrystals was used to screen the cocrystals using tools such as thermodynamic probability, ESP analysis, QTAIM analysis, and NBO analysis. The pairing energy of interaction was measured by determining H-bond donor ( ) and H-bond acceptor ) parameters for hydrogen bonds from maxima and minima on the ESP surface. GaussView 06 software was used to create, visualize, and plot the optimized structure of the cocrystal and HOMO-LUMO orbitals. The AIMALL (10.05.04) software package generated the molecular graph for intra- and intermolecular interactions. The RDG-scatter plot, MEP map, and ELF plot were rendered from Multiwfn 8.0 and VMD 1.9.1 software.

Green synthesis of silver nanoparticles by Smyrnium cordifolium plant and its application for colorimetric detection of ammonia

The need to identify ammonia is necessary because of its harmful effects on the environment and humans. In this study, a colorimetric method was also developed for the detection of ammonia using silver nanoparticles (AgNPs) synthesized with the green approach. Biosynthesis of AgNPs was performed by silver nitrate as a silver precursor and Smyrnium cordifolium extract as a reducing and stabilizing agent. Plant extract was studied by FTIR and LC/Mass techniques. The optimization of the effective parameters was carried out with central composite design according to silver nitrate concentration, plant extract volume, pH, and temperature. Biosynthetic nano-silver was characterized with XRD, EDS/EDX, FE-SEM, FTIR, TGA, and DLS methods. The AgNPs was validated for ammonia colorimetric detection. Biosynthesis of AgNPs were increased in 20 mM AgNO3, 5 ml Smyrnium cordifolium extract, pH 10, and the temperature of 70 °C. Crystal form of AgNPs characterized with XRD at 2Ѳ value of 38.34°, 44.19°, 64.74°, and 77.59° and spherical shape highlighted in the range between 77.8 and 93 nm. Plant extract consisted of polyphenol (phenolic acid, flavonoid, and terpenoid), fatty acid, amino acid, sugar, purine, and organic acid. AgNPs were used for colorimetric detection of ammonia by shifting the λmax from 580 to 490 nm. A method for ammonia detection was set up, with linear range of 0.5–200 ppm, detection limit of 0.028 ppm and recovery level of 96.3 ± 6.5%. In conclusion, a new biosynthetic method by specified local plant was developed to propose a simple and sensitive colorimetric method for soluble ammonia detection.

2,2'-Bipyridyl-4,4'-Dicarboxylic Acid Modified Buried Interface of High-Performance Perovskite Solar Cells.

The regulation of interfaces remains a critical and challenging aspect in the pursuit of highly efficient and stable perovskite solar cells (PSCs). Here, 2,2'-bipyridyl-4,4'-dicarboxylic acid (HBPDC) is incorporated as an interfacial layer between SnO2 and perovskite layers in PSCs. The two carboxylic acid moieties on HBPDC bind to SnO2 through esterification, while its nitrogen atoms, possessing lone electron pairs, interact with uncoordinated lead (Pb2+) atoms through Lewis acid-base interactions. This dual functionality enables simultaneous passivation of surface defects on both the SnO2 and buried perovskite layers. In addition, the electron-deficient nature of HBPDC enhances interfacial energy band alignment and facilitates electron transfer from the perovskite to SnO2. Furthermore, the incorporation of HBPDC strengthens the interfacial adhesion, improving mechanical reliability. As a result, the PSCs exhibited an impressive power conversion efficiency (PCE) of 25.41% under standard AM 1.5G conditions, along with remarkable environmental stability.