Water-soluble Complexes Research Articles

Metal-Coordinated Polymer-Inorganic Hybrids: Synthesis, Properties, and Application.

This review examines the recent advancements and unique properties of polymer-inorganic hybrid materials formed through coordination bonding (Class II hybrids), which enable enhanced functionality and stability across various applications. Here, we categorize these materials based on properties gained through complexation, focusing on electrical conductivity, thermal stability, photophysical characteristics, catalytic activity, and nanoscale self-assembly. Two major synthetic approaches to making these hybrids include homogeneous and heterogeneous methods, each with distinct tradeoffs: Homogeneous synthesis is straightforward but requires favorable mixing between inorganic and polymer species, which are predominantly water-soluble complexes. In contrast, heterogeneous methods are post-processing techniques that provide high area selectivity for inorganic precursors, allowing precise integration within polymer matrices. Finally, we highlight the role of hybrid linkers, namely metallosupramolecular polymers, in creating structural diversity. These can be organized into three main groups: metal-organic frameworks (MOFs), coordination polymers (CPs), and supramolecular coordination complexes (SCCs). Each of these groups introduces unique structural and functional properties that expand the potential applications of hybrid materials.

On the Architecture of Starch Granules Revealed by Iodine Binding and Lintnerization. Part 2: Molecular Structure of Lintnerized Starches.

This investigation validated iodine binding in combination with lintnerization for studying the structural nature of the amorphous areas in starch granules. Lintners of four iodine vapor-stained and non-stained amylose-containing starches and their waxy counterparts were analyzed by high-performance anion-exchange chromatography (HPAEC). The composition of the lintners was strongly affected by the absence of amylose in barley and potato starch but not in maize and cassava starch. Iodine-stained waxy lintners possessed increased number of long B2 chains. β-Limit dextrins of the lintners were very variable in composition. Iodine inclusion complexes washed out from the granular residues in the lintners (mostly from amylose-containing barley and maize starches) were also analyzed. Acid-soluble complexes from both amylose-containing and waxy starches possessed a lot of material with a degree of polymerization (DP) around 60 and a periodicity in size of DP 8-12. Such long chains were only minor components in water-soluble complexes of amylose-containing barley and maize starch lintners, and they lacked the size periodicity. Models of the principal structure of the acid and water-soluble complexes are suggested. It is concluded that acid hydrolysis of iodine-stained starch granules is a useful tool in structural analyses of the molecular composition of amorphous parts of starch granules.

Investigation of a novel Schiff base Catena-((μ6-(E)-2-((4-methoxy-2-oxidobenzylidene)ammonio)ethane-1-sulfonato potassium as a potential antibacterial agent.

Schiff bases, which have intriguing properties in many areas, have been studied extensively in recent years due to their structural properties and biological activities. In this research, a novel water-soluble Schiff base complex, Catena-((μ6-(E)-2-((4-methoxy-2-oxidobenzylidene) ammonio) ethane-1-sulfonato potassium, C10H14KNO6S (CMOAESP), was synthesized by a one-step condensation reaction of 2-hydroxy-4-methoxy benzaldehyde and taurine with the yield of 65%, 0.333g. Spectral analysis of water-soluble crude product showed equilibria keto-enol tautomerism, by a resulting Zwitterionic form of the structure. The ADMET prediction showed that the CMOAESP obeys Lipinski's rule and was in bioavability range. The molecular docking results showed an inhibition ability for 1JIJ and MBT1 proteins which play an important role in antibacterial studies. The experimental end theoretical calculations were in a good agreement that CMOASP has inhibition efficiency against Escherichia coli and has inhibition at high concentrations against Staphylococcaceae aureus. The WinGX software system SHELXS direct technique was used to solve the structure, and SHELXL full-matrix least-squares approach on F2 was used to refine the results. The Gaussian 09W program was used to carry out the DFT calculations. The gap values for CMOAESP were calculated by using the B3LYP/6- 311 + + G(d,p) method in order to predict its reactivities and behaviors in the gas phase. The frontier orbitals, LUMO and HOMO together with some global parameters as electronegativity (μ), chemical potential (χ), hardness (η), electrophilicity index (ω), and softness (S) values were predicted from DFT calculations.

Efficient electrochemical water oxidation catalyzed by a novel nickel complex: Critical effect of the flexibility of pyridine-amine based pentadentate ligand on catalytic property

Efficient electrochemical water oxidation can be realized by reasonable modulation of the ligand structure of metal complex-based molecular water oxidation catalysts (WOCs). Herein, the synthesis and prowess in electrocatalytic water oxidation of a mononuclear water-soluble nickel complex, [Ni(tmbptu)(OH2)](ClO4)2 (1, tmbptu = 2,6,10-trimethyl-1,11-bis(2-pyridyl)-2,6,10-triazaundecanone), is reported for the first time. Complex 1 is found to be an efficient homogeneous WOCs under near neutral condition with long-term catalytic stability by a series of characterizations, including dynamic light scattering (DLS) measurement, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX) analysis, chelation experiment, and Fe3+ test. Electrochemical tests reveal that water oxidation is accomplished via the generation of NiIV species generated by two successive e−/H+ proton coupled electron transfer (PCET) processes. Astonishingly, compared to the homologous complex [Ni(tmbptn)(OH2)](ClO4)2 (2, tmbptn = 2,5,8-trimethyl-1,9-bis(2-pyridyl)-2,5,8-triazanonane), which is a well-defined molecular WOC with high catalytic onset overpotential, 1 displays lower onset overpotential and much higher catalytic activity. This work suggesting that though the tertiary amine coordination environment have gain effect on the redox potential of metal center due to its poor sigma-donor effect, resulting in high onset overpotential of metal complex for water oxidation, this negative impact of the pyridine-amine ligand on the catalytic properties of complex can be weaken by adjusting the flexibility of backbone of those ligands.

Preparation of Water-Soluble Polyion Complex (PIC) Micelles with pH-Responsive Carboxybetaine Block.

A dual zwitterionic diblock copolymer (M100C100) consisting of poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC, M) and poly(3-((2-(methacryloyloxy)ethyl) dimethylammonio) propionate) (PCBMA, C) is synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. A double hydrophilic diblock copolymer (M100S100) consist of PMPC and anionic poly(3-sulfopropyl methacrylate potassium salt) (PMPS, S) is synthesized via RAFT. The degrees of polymerization of each block are 100. The charges of PMPC are neutralized intramolecularly. At neutral pH, the charges in PCBMA are also neutralized intramolecularly due to its carboxybetaine structure. Under acidic conditions, PCBMA exhibits polycation behavior as the pendant carboxy groups become protonated, forming cationic tertiary amine groups. PMPS shows permanent anionic nature independent of pH. Charge neutralized mixture of cationic M100C100 and anionic M100S100 in acidic aqueous solution forms water-soluble polyion complex (PIC) micelle owing to electrostatic attractive interactions. The core is composed of the cationic PCBMA and anionic PMPS blocks, with the PMPC blocks serving as shells that covered the core surface, forming spherical core-shell PIC micelles. Above pH 4 the pendant carboxy groups in PCBMA undergo deprotonation, transitioning to a zwitterionic state, thereby eliminating the cationic charge in PCBMA. Therefore, above pH 4 the PIC micelles are dissociated due to the disappearance of the charge interactions.

Rapid release of high-valent silver ions from water-soluble porphyrin complexes to enhance the direct killing of Methicillin-Resistant Staphylococcus aureus

The emergence of multidrug-resistant (MDR) bacteria represented by MRSA (Methicillin-resistant Staphylococcus aureus) poses a great challenge to current anti-infection treatment. It is critical to develop efficient MRSA anti-bacteria drugs and explore simple therapeutic strategies with low MDR risk. Herein, we synthesized high-valent (AgII/AgIII) water-soluble porphyrins (cationic AgTMPyP and anionic AgTMPPS) and investigated their direct bactericidal property for MRSA without photoactivation in vitro and in vivo. The cationic porphyrin AgTMPyP exhibits well oxidase-like activity and has 100% sterilizing rate at 8 μmol/L concentration. Besides, AgTMPyP can effectively destroy biofilms in vitro, mediate the polarization of macrophages from M1 to M2, and promote wound healing in vivo. Combined with DFT calculation, the related antibacterial mechanism is further discussed. High-valent silverporphyrins can maintain stable in water for at least 200 days. The moment they encounter MRSA, high-valent silver ions from AgTMPyP can be immediately released from the porphyrin ring and attack the MRSA with efficient sterilization. Together with the hemolysis, blood routine and blood biochemistry tests, it is proved that AgTMPyP can have great prospects in the direct treatment of bacterial infections in skin diseases in the future. Statement of significance: The emergence of multidrug-resistant (MDR) bacteria represented by MRSA poses a great challenge to current anti-infection treatment. It has become critical to develop efficient MRSA anti-bacteria drugs and explore simple therapeutic strategies with low MDR risk. We synthesized high-valent (AgII/AgIII) water-soluble silver porphyrins (AgTMPyP and AgTMPPS), which can be stable for long periods in aqueous solutions. AgTMPyP can directly and efficiently kill bacteria and destroy biofilms without photoactivation in vitro and in vivo. Combined with DFT calculation, the related antibacterial mechanism is further discussed. AgTMPyP is a superior antimicrobial agent with good biocompatibility and it can have great prospects in the direct treatment of bacterial infections and wound healing in the future.

Study of Host-Guest Interaction and In Vitro Neuroprotective Potential of Cinnamic Acid/Randomly Methylated β-Cyclodextrin Inclusion Complex.

Cinnamic acid (CA) has many beneficial effects on human health. However, its poor water solubility (0.23 g/L, at 25 °C) is responsible for its poor bioavailability. This drawback prevents its clinical use. To overcome the solubility limits of this extraordinary natural compound, in this study, we developed a highly water-soluble inclusion complex of CA with randomly methylated-β-cyclodextrin (RAMEB). The host-guest interaction was explored in liquid and solid states by UV-Vis titration, phase solubility analysis, FT-IR spectroscopy, and 1H-NMR. Additionally, molecular modeling studies were carried out. Both experimental and theoretical studies revealed a 1:1 CA/RAMEB inclusion complex, with a high apparent stability constant equal to 15,169.53 M-1. The inclusion complex increases the water solubility of CA by about 250-fold and dissolves within 5 min. Molecular modeling demonstrated that CA inserts its phenyl ring into the RAMEB cavity with its propyl-2-enoic acid tail leaning from the wide rim. Finally, a biological in vitro study of the inclusion complex, compared to the free components, was performed on the neuroblastoma SH-SY5Y cell line. None of them showed cytotoxic effects at the assayed concentrations. Of note, the pretreatment of SH-SY5Y cells with CA/RAMEB at 10, 30, and 125 µM doses significantly counteracted the effect of the neurotoxin MPP+, whilst CA and RAMEB alone did not show any neuroprotection. Overall, our data demonstrated that inclusion complexes overcome CA solubility problems, supporting their use for clinical applications.

Sulfur in Tephra of Opala Volcano Eruption ca. 1500 years ago, Kamchatka

Sulfur-bearing compounds of Plinian-type volcanic eruptions can be transferred with ash particles of distal tephra over considerable distances. Average sulfur content in tephra of Opala volcano (Kamchatka, eruption ca. 1500 years ago) comprises 310 ppm with maximum concentration up to 800 ppm. Connection detected between sulfur content in bulk samples and the particle size distribution – sulfur is predominantly contained in the fraction 0.25‒0.50 mm represented by elongated ash particles with elongated gas pores 1.0‒10.0 mkm in diameter. The most likely reason for the dependence of sulfur content on the texture of ash particles is preservation of sulfur compounds of the water-soluble complex inside gas pores. Sulfur-containing compounds deposited on the surface of ash particles were removed by precipitation in the process of existing tephra in continental environment. Ingress of ash particles into bottom sediments containing sulfur compounds on the inner surface of gas pores during plinian type eruptions similar to the eruption of Opala volcano ca. 1500 years ago, may influence the geochemistry of lithogenesis and lead to redistribution of elements sensitive to the presence of acid-forming agents in the sediment at the stage of diagenesis.

Water-soluble lanthanide complexes with bispidine-substituted benzoic acid for luminescent thermometry in a physiological range

A novel material based on europium and terbium complexes with a bispidine-substituted benzoate anion for luminescent thermometry in the physiological temperature range was obtained. The obtained complexes demonstrated intense visible luminescence with quantum yields up to 75%, high water solubility, and high luminescence sensitivity toward temperature (Sr = 2.1% K–1).

Water-soluble neutral octahedral chalcogenide tungsten and molybdenum {M6Q8} clusters with P(C2H4CONH2)3 ligand

Developing the chemistry of octahedral chalcogenide molybdenum and tungsten cluster complexes in the context of applications in biology and medicine, in this work a series of water-soluble neutral cluster complexes [{M6Q8}(P(C2H4CONH2)3)6] (M = Mo, W; Q = S, Se) have been obtained by simultaneous replacement of inner and terminal halide ligands in [{M6I8}I6]2− with chalcogenide and organic phosphine ligands and characterized by single-crystal X-ray diffraction analysis, 1H and 31P NMR spectroscopies, elemental analysis, and UV–vis spectroscopy. The amide groups of the organic ligands, on the one hand, contribute to the solubility of the resulting clusters in water and, on the other hand, are able to form an extensive network of hydrogen bonds, leading to the crystallization of the complexes from aqueous solutions. Despite this fact, the complexes have sufficient solubility and stability in aqueous solutions, which made it possible to demonstrate their low cytotoxicity on Hep-2 cells (IC50 were not reached even at concentration up to 4 mM). The resulting clusters are among the most biocompatible of the octahedral clusters studied to date and are the starting point for the development of a new family of X-ray contrast agents.

Neutral water-soluble µ-S nitrosyl iron complex with acetylcysteine non-silent in EPR spectra

The water-soluble neutral binuclear nitrosyl iron complex with N-acetyl-L-cysteine was synthesized. As follows from X-ray analysis, the complex crystallizes in the monoclinic crystal system, space group P2(1). The distance between iron atoms is 2.7 Å The complex belongs to Roussin's red salt esters (RRE) and is expected to be diamagnetic. However, in the EPR-spectrum there is a broad line with a g-factor of 2.010, which disappears upon the dissolution of the complex in water or alcohol. However, dissolution of the complex in DMSO leads to an increase in the classical signal for mononuclear nitrosyl iron complex with a g-factor of 2.03. The IR-spectrum of the crystalline sample of the complex shows an atypical pattern among RREs. This behaviour was studied with quantum-chemical calculations. The magnetic properties of the complex are also unusual for a complex of this structural type. The complex was also studied by Mössbauer and UV-spectroscopy.

From Simple Probe to Smart Composites: Water-Soluble Pincer Complex With Multi-Stimuli-Responsive Luminescent Behaviors.

Water-soluble smart materials with multi-stimuli-responsiveness and ultra-long room-temperature phosphorescence (RTP) have garnered broad attention. Herein, a water-soluble terpyridine zinc complex (MeO-Tpy-Zn-OAc), featuring a simple donor-π-acceptor (D-π-A) structure is presented, which responds to a variety of stimuli, including changes in solvents, pH, temperature, and the addition of amino acids. Notably, MeO-Tpy-Zn-OAc functions as a fluorescence probe, capable of visually and selectively discriminating aspartate or histidine among other common amino acids in water. Additionally, when incorporated into polyvinyl alcohol (PVA) to form the composite MeO-Tpy-Zn-OAc@PVA, the material exhibits reversible writing, photochromism, and a prolonged RTP with a 14 s afterglow. These unique properties enable the composite to be utilized in potential applications such as secure data encryption and inkless printing.

Pd-imidate@SBA-15: a multifunctional heterogeneous catalyst for the aqueous room temperature hydrogenation of CO2 to formic acid.

The incorporation of hydrophilic and basic sites from phosphotriazaadamantane and saccharine in a water-soluble Pd complex and the subsequent confinement into mesoporous silica support increases the activity and stability of the palladium catalytic species for the room-temperature aqueous hydrogenation of either bicarbonate or CO2 into formic acid. The use of low Pd loadings (<0.1mmolPd·g-1) of the well-dispersed complex on SBA-15 mesoporous silica allows performing the reaction under room temperature, and aqueous conditions, exhibiting TON of ca. 40-100, for the CO2 or bicarbonate hydrogenation, respectively, which is one order of magnitude higher than the homogeneous case, allowing the easy isolation and recycling of the solid catalyst.

Improving the Photodynamic Activity of Water-Soluble Porphyrin-Polysaccharide Complexes by Folic Acid Modification.

Studies have shown that folate receptors are highly expressed in various cancer cells. Here, we synthesized folic acid-conjugated pullulan (FAPL) as a solubilizing agent to improve the photodynamic activity of porphyrin derivative-polysaccharide complexes. The porphyrin derivative-FAPL complex exhibited long-term stability in an aqueous solution, attributed to the folic acid modification. Furthermore, in vitro and in vivo experiments highlighted the enhanced photodynamic activity of the porphyrin derivative-FAPL complex toward 4T1 breast-cancer cells, compared with the activities of the porphyrin derivative-pullulan complex and Photofrin. This enhanced activity is attributed to the improvement of intracellular uptake by the folate receptor.

Characterization and biological activity evaluation of water-soluble resveratrol complexes obtained by spray drying, ball milling and jet milling

To increase the water solubility of resveratrol (RES) and explore the possibility of solid-phase preparation technology as an alternative to traditional spray drying technology. In this study, herein, three resveratrol-stevia glycoside-hydroxypropyl-β-cyclodextrin (RES-STE-HP-β-CD) complexes were prepared by jet milling, ball milling and spray drying. The three complexes were subjected to saturation solubility determination, characterization (SEM, XRD, FT-IR and 1H NMR), antioxidant activity evaluation and in vitro cytotoxicity assay. The results demonstrated that RES was successfully complexed with STE and HP-β-CD, and the crystalline state of RES was changed after the complexation. The water solubility of RES increased about 30 times, and the saturated solubility of the complexes prepared by jet milling reached the highest of 993.32 μg/mL. Meanwhile, RES could interact with STE through hydrogen bonding, and also could be probably inserted into the cavities of HP-β-CD. Moreover, the complexes prepared by different methods possessed good antioxidant activity and did not exhibit significant cytotoxicity. In conclusion, STE&HP-β-CD can effectively solubilize RES, and solid-phase preparation technologies (e.g., jet milling) have the potential to prepare water-soluble complexes. The complex powders can be used as raw materials for nutraceuticals or pharmaceuticals.

Water-soluble Schiff base ligands and metal complexes: an overview considering green solvent.

The water-soluble metal complexes with Schiff base (SB) ligands are of great interest to green chemistry researchers due to their stability, cost-effectiveness, eco-friendly, electron-donating ability, and various applications. They have high potential to express their biological activity including anti-inflammatory, anticancer, antibacterial, antifungal, antioxidant, and DNA binding and cleavage. In the recent era, transition metal complexes have played a significant role in different processes such as hydrogenation, carbonylation, oxidation, reduction, epoxidation, hydrolysis, decomposition, and polymerization reactions in industry. However, their limited aqueous solubility may be the major limitation to their potential catalytic, industrial, and clinical applications. In industrial catalytic processes, it has been proven that water can be used as a solvent to minimize the environmental effect of different reactions as well as simple and complete separation. Water is a green solvent, flexible, non-toxic, safe, readily available, environmentally harmless, and inexpensive. Attaching different substituents on Schiff bases enhances the water solubility and catalytic activity. Studies on water-soluble SB complexes will explore these aspects and their prospects for the future evolution of their diverse applications.

Curcumin- β-Cyclodextrin Molecular Inclusion Complex: A Water-Soluble Complex in Fast-dissolving Tablets for the Treatment ofNeurodegenerative Disorders.

Orally disintegrating tablets (ODTs) have become an excellent choice for delivering drugs as their palatability is greatly improved. In this work, β-cyclodextrin has been used to improve the solubility of curcumin by encapsulating it into the hydrophobic cavity for the treatment of neurodegenerative disorders. The current study aimed to present the design, formulation, and optimisation of fastdissolving oral tablets of curcumin- β-cyclodextrin molecular inclusion complex using a 32-factorial design. The drug-excipient compatibility was studied by FTIR spectroscopy. The inclusion complex of curcumin-β-cyclodextrin was prepared using solvent casting and confirmed using XRD studies. Powder blends were evaluated for flow properties. Tablets prepared by direct compression were evaluated for post-compression parameters. Further, the effect of formulation variables, such as sodium starch glycolate (X1) and Neusilin® ULF2 (X2), on various responses, including disintegration time and dissolution at 2 hours, was studied using statistical models. Post-compression parameters, i.e., hardness (4.4-5 kg/cm2), thickness (3.82-3.93 mm), weight variation (±7.5%), friability (< 1%), wetting time (51-85 seconds) and drug content (96.28- 99.32%) were all found to be within the permissible limits and the disintegration time of tablets with super-disintegrants ranged between 45-58 seconds. The in-vitro dissolution profile of tablets showed that higher SSG and Neuslin® ULF2 levels promoted drug release. For statistical analysis, the 2FI model was chosen. Optimised variables for formulation have been determined and validated with the experimental findings based on the significant desirability factor. The current study reveals the validated curcumin-β-cyclodextrin inclusion complex fastdissolving tablets with SSG and Neusilin® ULF2 to be an ideal choice for effectively treating neurodegenerative disorders.

Synthesis and crystal structure of new Mn (III) complex; a target catalyst for direct conversion of thiols after heterogenization

In this study, we are interested in the synthesizing of a new water-soluble complex of Mn (III) formulated as [Mn(pzo)(dipic)(H2O)2]2·3H2O; hereafter referred to as complex 1 where pzo− = pyrazonate and dipic2− = pyridine-2,6-dicarboxylate, under hydrothermal conditions. The molecular structure of complex 1 is primarily determined by single crystal X-ray diffraction (SC-XRD) which shows two mono-nuclear complexes of Mn (III) with three lattice water molecules. According to SC-XRD, complex 1 crystallizes in space group P1¯ of a triclinic system. The center of Mn (III) is seven-coordinated with a distorted pentagonal-bipyramidal geometry with three oxygen atoms and two nitrogen atoms in the equatorial plane. Two oxygen atoms of two water molecules are coordinated in the axial positions. In addition, the structure of complex 1 has been studied by elemental analysis (CHN), Fourier-transform infrared spectroscopy (FT-IR (, thermogravimetric analysis/differential thermal analysis/differential thermogravimetry (TGA/DTA/DTG). Complex 1 has been immobilized on the silica-coated Fe3O4 nanoparticles to produce an efficient and recyclable heterogeneous catalyst formulated as Fe3O4@SiO2@1; hereafter referred to as catalyst 1. Catalyst 1 was characterized by inductively coupled plasma optical emission spectrometry (ICP-OES), energy-dispersive X-ray spectrometer (EDS), FT-IR, scanning electron micrograph (SEM), powder X-ray diffraction pattern (PXRD), and Brunner-Emmet-Teller (BET). 1 was used as a new heterogeneous catalyst for the oxidative coupling of thiols to their corresponding disulfides using 30 % H2O2. Under optimum reaction conditions, catalyst 1 exhibited high catalytic activity. 1 can be recovered by a magnet and reused for at least 7 consecutive cycles without significant loss of catalytic performance.

Stress Management Practices in Rainfed Sorghum (K12) on Yield, Economics and Plant Nutrient Uptake Through Foliar Plant Nutrition Under Typical Vertisols (Typic chromusterts) of Semiarid Region

ABSTRACT Foliar fertilization has great potential to give higher yields under intensive cropping system and in enhancing the crop tolerance to drought conditions. Different responses of yield to foliar fertilization are probably associated with incorrect timing of application, use of inappropriate fertilizer and lack of concern of soil available nutrients and environmental conditions. Though soil application of nutrients cannot be replaced totally with foliar fertilization, but under various situations like rainfed condition, foliar nutrition can play very important role in enhancing crop yield and nutrient use efficiency. Focusing on this, a field experiment was conducted in the Agricultural Research Station, Kovilpatti, under rainfed situation from 2017 to ‘20 to evaluate the response of foliar application of plant nutrients sprayed during moisture stress condition and to improve the growth and yield of sorghum under rainfed condition. This experiment was laid out in split plot design with replicated thrice and the treatments consisted of main plots: M1 – foliar spray during dry spell, M2 – foliar spray after relieving of stress/dry spell (with favorable soil moisture) and subplots: S1 – urea@1%, S2 – urea@2%, S3 – water soluble complex fertilizer (19:19:19)@0.5%, S4 – water soluble complex fertilizer (19:19:19)@0.5% + recommended dose of micronutrient for foliar spray (to be decided based on soil test: zinc, boron, iron, manganese, etc.), S5 – ZnSO4@0.5%, S6 – water spray, S7 – control (no spray of any material/water) under rainfed vertisols of semiarid region. The obtained results showed that the application of water soluble complex fertilizer (19:19:19)@0.5% sprayed during the dry spell significantly increased the plant height, earhead length and grain test weight. This attributes resulted in higher grain yield (1448 kg ha−1), stover yield (2288 kg ha−1), net returns (Rs. 8748 ha−1), B:C (1.16) and rainwater use efficiency (3.85 kg ha−1-mm) when compared to other practices in rainfed sorghum. There is a gradual increase in total major plant nutrient uptake, viz. nitrogen (22.3 kg ha−1), phosphorus (4.56 kg ha−1) and potassium uptake (26.0 kg ha−1) with the foliar application of water soluble complex fertilizer (19:19:19)@0.5% applied during the dry spell condition (S3) during drought stress condition (M1). Foliar application of nutrients along with soil application has several advantages in supplementing the nutritional requirements of crops such as rapid and efficient response by the plants, less product needed and independence of soil conditions. Foliar nutrition designed to eliminate the problems like fixation and immobilization of nutrients. Hence, foliar nutrition is recognized as an important method of fertilization during the dry spell under rainfed condition in modern agriculture.

Development of Highly Sensitive and Selective Electrochemical Glucose Sensors Based on the Modification of the Surface, Structural, and Morphological Properties of ZnO Using Vitamin-B Complexes

Non-enzymatic electrochemical glucose sensors are particularly advantageous because of their simplicity, low cost, efficiency, and long storage life. ZnO structures were modified with water-soluble vitamin B12, B9, and B6 complexes in alkaline 0.1 M NaOH solutions to enhance glucose sensing. ZnO samples were hydrothermally synthesized using 5 mg fixed masses of B12, B9, and B6 complexes. X-ray diffraction, scanning electron microscopy, UV-visible spectrometry, and Fourier transform infrared spectroscopy were used to determine crystalline properties, morphology, and optical band gap. Zinc oxide obtained from vitamin B complexes had a hexagonal structure similar to wurtzite, modified nanorods on its surface, and a reduced optical band gap. The molecular weight, size, and number of functional groups vitamins also influenced surface and structural characteristics of ZnO. Zinc oxide from the B12 complex proved excellent for non-enzymatic glucose sensing in alkaline conditions. B12-derived ZnO glucose sensors have a linear range of 0.1 to 10 mM with a detection limit of 0.005 mM. In the glucose sensing process, a satisfactory level of stability, reproducibility, and selectivity was observed. Furthermore, it was found that ZnO derived from B12 had a high electrical conductivity, which facilitated electron transfer during glucose oxidation.