UV Absorption Peak Research Articles

In silico and in vitro investigation of the role of Asparagus racemosus lead compound Shatavarin IV and associated silver nanoparticles

Antibiotic-resistant microbes are a global threat, necessitating the need for new antibacterials. Bioactive compounds obtained from Asparagus racemosus and silver nanoparticles synthesized from it were tested for antibacterial activity. The nanoparticles exhibited a UV absorbance peak at 415nm. SEM image revealed elliptical nanoparticles from 32.6 nm to 78.6 nm while the FTIR study of aromatic amine N-H and C-O stretching indicates the stability of the silver nanoparticle. Zeta potential and XRD tests confirmed the presence of silver nanoparticles in the root extract under stable conditions. Methanolic root extract and silver nanoparticles were found to be very effective against Bacillus subtilis (20mm), Salmonella typhimurium (20mm), Escherichia coli (20mm), Klebsiella pneumoniae (18mm), Staphylococcus aureus (17mm) and Pseudomonas aeruginosa (15mm) in comparison to ampicillin. AutoDock Tools 1.5.7 was used to perform molecular docking of Shatavarin IV against target proteins involved in breast cancer (PDB ID: 3O96), bacterial infections (PDB ID: 2ZCO), viral infections angiotensin (PDB ID: 4APH) and inflammation (PDB ID: 7PHS). The respective best docking scores are -18.66, -18.07 -14.57 and -15.84 Kcal/Mol respectively. Sarsasapogenin and Kaempferol also showed favorable docking scores with specific target proteins. Shatavarin IV is found to target amino acid(s) and the standard drugs of each category such as Remdesivir for viral, Diclofenac for inflammation, Tamoxifen for cancer and Plazomicin for bacterial infections. This study reveals that Asparagus racemosus bioactive compound Shatavarin IV is a suitable lead compound for the treatment of cancer, viral, bacterial infections and inflammatory conditions.

Green synthesis and biophysical characterization of silver and palladium nanoparticles using Laureliopsis philippiana: A potent eco-friendly larvicide with negligible impact on zebrafish (Danio rerio)

Green nanoparticles represent a sustainable and eco-friendly approach to developing larvicides targeted at controlling mosquito populations. These nanoparticles are synthesized using natural, non-toxic materials and environmentally benign processes, emphasizing their potential to combat mosquito larvae while minimizing adverse effects on the ecosystem. This approach aligns with the growing need for sustainable solutions in vector control, providing an effective alternative to traditional larvicides with reduced environmental impact. The aim of the present investigation we have utilized the leaf from Laureliopsis philippiana (LP) to synthesize silver (Ag) and palladium (Pd) nanoparticles (NPs) and studied toxicity on deadly disease vectors larvae of Aedes aegypti and Anopheles stephensi. Biosynthesized Ag and Pd NPs were extensively characterized through physical and chemical methods. Gas chromatography–mass spectrometry analysis of L. philippiana assisted in identifying the secondary metabolites of the extract's total flavonoid and phenolic compounds, which are in the reactants of the bio-reduction process during the production of NPs. The in-silico analysis was conducted on mosquito sterol carrier protein-2 (1PZ4) and mosquito odorant binding protein (2L2C). The biosynthesized Ag and Pd NPs revealed the UV absorption peak at 417 and 370 nm, and X-ray diffraction results showed the crystalline structure of NPs. At the same time, in transmission electron microscopy representation, the Ag and Pd NPs were spherical, clustered, and exhibited a noticeable average size of Ag NPs: 13.25 ± 2.53 nm and Pd NPs: 4.07 ± 1.64 nm. The biogenic Ag and Pd NPs showed concentration-dependent larvicidal mortality at 12 and 24-hour exposure with LC50 values of 29.596, 17.804, and 23.915, 14.878 µg/mL on Ae. aegypti and 23.946, 13.938, 19.457, and 12.876 µg/mL against An. stephensi, correspondingly. In-silico studies proved that Laureliopsine A and isoterpinolene showed significant docking scores compared to permethrin on mosquito proteins (1PZ4 and 2L2C). Besides, the LP-Ag and Pd NPs non-toxicity analysis was carried out on zebrafish (Danio rerio) embryos at 72 h post-fertilization. Overall, the findings clearly demonstrated the green synthesized Ag and Pd NPs from L. philippiana to develop environmentally secure and safe larvicides.

Chemical Detoxification of Therapeutic Hybrid Complexes Prepared by the Compatible Combination of Ayurvedic Herb and Allopathic Drug

Background & Objective: The treatment of diseases and good health maintenance are the common fundamental aims of ayurvedic and allopathic medical systems. Limited information is available in the public domain for the concept of symbiohealth, i.e., the symbiotic interaction of ayurveda and allopathy, that needs to be explored for an efficient and robust health system. Therefore, an attempt has been made to reduce the toxicity of therapeutic drugs via the integration approach of ayurveda and allopathy. Methods: Three different categories of allopathy and ayurvedic medicines, such as antacids (omeprazole, ranitidine, and sooktybhasma), antibacterial (amoxicillin trihydrate, ciprofloxacin hydrochloride, Curcuma longa, and Datura stramonium) and antiviral (acyclovir, efavirenz, Echinacea, Calendula, Allium sativum, and Citrullus colocynthis) were targeted. Results: Best therapeutic hybrid combination was obtained on the basis of their UV absorption maxima and peak shift. Acyclovir with A. sativum (1-6%), sooktybhasma 20% with rantidine, Ciprofloxacin HCl (2%) with 10% aqueous datura and Ciprofloxacin HCl (0.02-0.2%) with 0.02-0.06% acetonitrile turmeric showed best integration result. This drug integration can be applied to improve the potential results or detoxification of hybrid drugs that target the drug moiety results in reduced side effects or the dose of important drugs, which might be due to the chelation pattern of their functional group, absorption, bonding, and pi-pi interaction. Conclusion: This study will provide the leadership for the betterment of a therapeutic hybrid drug complex that might be useful as an allopathic drug and less harmful than its ayurvedic component. The proposed integration fusion of different medication therapies, such as Ayurvedic and allopathic, has the potential for a scientific merger.

A new SERS quantitative analysis method for trace malathion with recognition and catalytic amplification difunctional MOFTb@Au@MIP nanoprobe

New multifunctional nanomaterial preparation and its application to trace pollutant analysis are interesting to peoples. Using terbium metal-organic framework loaded gold nanoparticles (MOFTb@Au) as the nanosubstrate and 3-aminopropyltriethoxysilane (APTES) as the functional monomer, a new bifunctional nanosurface molecularly imprinted polymer nanoprobe of MOFTb@Au@MIP with strongly recognition and catalytic amplification functions was prepared by the microwave sol-gel procedure. It was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier infrared spectroscopy (FTIR) and other techniques. The nanoprobe was found to specifically recognize malathion (MAL) and catalyze the L-cysteine (Cys)-HAuCl4 nanogold indicator reaction to amplify the molecular spectral signal. The gold nanoparticles (AuNPs) generated in the system show a strong surface-enhanced Raman scattering (SERS) effect, resonant Rayleigh scattering (RRS) peak and UV absorption (Abs) peak at 1615 cm−1, 370 nm and 520 nm, respectively. Based on this, a new SERS/RRS/Abs trimode method for the detection of MAL can be established. It has been applied to the analysis of cereal samples with satisfactory recoveries of 95.2–107.4% and precision of 3.76–9.06%.

Fabrication of Ag-CaCO3 Nanocomposites for SERS Detection of Forchlorfenuron.

In this study, Ag-CaCO3 nanocomposites were synthesized using silver nitrate as the precursor solution based on calcium carbonate nanoparticles (CaCO3 NPs). The synthesis involved the reaction of calcium lignosulphonate and sodium bicarbonate. The properties of Ag-CaCO3 nanocomposites were studied by various technologies, including an ultraviolet-visible spectrophotometer, a transmission electron microscope, and a Raman spectrometer. The results showed that Ag-CaCO3 nanocomposites exhibited a maximum UV absorption peak at 430 nm, the surface-enhanced Raman spectroscopy (SERS) activity of Ag-CaCO3 nanocomposites was evaluated using mercaptobenzoic acid (MBA) as the marker molecule, resulting in an enhancement factor of 6.5 × 104. Additionally, Ag-CaCO3 nanocomposites were utilized for the detection of forchlorfenuron. The results demonstrated a linear relationship in the concentration range of 0.01 mg/mL to 2 mg/mL, described by the equation y = 290.02x + 1598.8. The correlation coefficient was calculated to be 0.9772, and the limit of detection (LOD) was determined to be 0.001 mg/mL. These findings highlight the relatively high SERS activity of Ag-CaCO3 nanocomposites, making them suitable for analyzing pesticide residues and detecting toxic and harmful molecules, thereby contributing to environmental protection.

Multifunctional Probe Based on CTAB-Cu Nanoparticles for Fluorescence and Colorimetric Dual-Read-Out Determination of p-Nitrophenol and Glyphosate

The quantitative analysis of glyphosate has significant implications for the evaluation of food quality and environmental safety risks. First, copper nanoparticles (Cu NPs) were synthesized using cetyltrimethylammonium bromide (CTAB) as a stabilizing agent, which resolved the limitation associated with atmospheric oxidation of Cu NPs and provided excellent fluorescence stability. Interestingly, the fluorescence of blue-emitting CTAB-Cu NPs was quenched by pH-responsive p-nitrophenol (p-NP) via Förster resonance energy transfer. Herein, a dual read-out sensor based on CTAB-Cu NPs and p-NP was constructed for glyphosate detection. Specifically, acetic acid (HAc) from acetylcholine (ACh) via hydrolysis catalyzed by acetyl cholinesterase (AChE) reduced the pH of the mixed solution and prevented the loss of protons from p-NP, which allowed the fluorescence emission by CTAB-Cu NPs. The presence of glyphosate inhibited the activity of AChE, and the increased pH resulted in proton loss. The fluorescence intensity of CTAB-Cu NPs was quenched, and the solution color changed from colorless to yellow with a UV absorption peak at 400 nm. The sensor can detect ultra-trace levels of glyphosate residues with a limit of detection of 5.43 ng/L. The obtained biosensor was successfully utilized to monitor the degradation of glyphosate in the roots of cabbage and cultivated soil.

Effect of interaction between catechin and glycated porcine hemoglobin on its antioxidant functional and structural properties

This study aimed to investigate the interaction between catechins and glycated porcine hemoglobin (G-PHb). The effects of the interaction on the antioxidant function and structural characteristics of the complex (CG-PHb) of catechin and G-PHb were discussed. Porcine hemoglobin (PHb) and G-PHb were used as controls. The solubility, turbidity, emulsifying property, surface hydrophobicity, and oxidation resistance of CG-PHb were studied. The structural characteristics of the CG-PHb were analyzed via UV–visible spectroscopy, fluorescence spectrometry, fourier transform infrared spectroscopy, scanning electron microscope and molecular docking technology. Compared with the control group, these properties of the CG-PHb are significantly improved. The UV absorption peak of CG-PHb had a larger peak and a slight red shift. The fluorescence peak intensity was in the following order: CG-PHb > PHb > G-PHb. The β-sheet content of CG-PHb increased significantly (P < 0.05). Moreover, SEM showed that the structure of CG-PHb had changed. The surface pore structure increased, which facilitated its functional properties. Molecular docking showed that catechin likely interacted with PHb residues HEM-950, PHE-41, GLU-43, ARG-40 and LEU-96. Catechin and PHb formed a more stable complex because of hydrogen bonds. This study can provide new ideas for protein modification research and provide theoretical basis and reference for the property changes of the CG-PHb during food processing.

Nitrogen dioxide gas-sensing properties of hydrothermally synthesized WO3 · nH2O nanostructures.

Nitrogen dioxide (NO2) has been identified as a serious air pollutant that threats to our environment, human life and world ecosystems. Therefore, detection of this air pollutant is crucial. Metal oxide semiconductor is one of the best approaches frequently used to detect NO2 at relatively low temperatures. Hydrated tungsten trioxide (WO3 · H2O), an n-type semiconductor, is regarded to be a promising material for fabricating gas sensors, which are widely used in environmental and safety monitoring. In this work, WO3 · nH2O nanoparticles have been synthesized using a polyfunctional surfactant-mediated hydrothermal approach in the addition of H2C2O4 and K2SO4 at a molar ratio of 1 : 1. This paper has also reported the effect of reaction temperature (120°C to 200°C) on morphological changes and gas-sensing performance. The characterization of these synthesized nanostructures was carried out by UV-Vis absorption spectroscopy, X-ray diffraction and field-emission scanning electron microscopy (FESEM). The UV absorption peak was obtained around 300 nm. FESEM analysis showed sheet-like structures come together to form flower-type morphology. The synthesized WO3 · nH2O flower-like structures was then used for NO2 gas-sensing application. The prepared sensors showed considerably better sensor response (R g/R a = 17.48) at 185°C for 25 ppm NO2.

Synthesis of novel coordination polymer Cd-MOF and fluorescence recognition of tryptophan

The coordination polymer Cd-MOF with three-dimensional network structure was successfully synthesized by conventional solvothermal method, which possesses excellent chemical and structural stability. Among the 20 amino acids, only tryptophan (Trp) showed a significant fluorescence enhancement effect on Cd-MOF, which was attributed to the large overlap between the UV absorption peak of tryptophan and the fluorescence excitation spectrum of Cd-MOF, indicating that the UV absorption of them is competitive, which enhanced the UV absorption of Cd-MOF and thus enhanced the luminescence intensity simultaneously. The Cd-MOF was further found to have a low detection limit of 1.7µM, a relatively wide linear range (0-100µM) and a stable response time for the recognition of tryptophan, as well as a good resistance to the interference of other amino acids. The method has been successfully applied to the spiked recovery determination of tryptophan in milk with the recoveries of 99.6%-101% and RSD≤1.50%. Therefore, this work demonstrated that Cd-MOF can be used as a fluorescent probe for the selective detection of tryptophan, and also may provide new opportunities for the rational design of future tryptophan fluorescent probes.

Poly(3-amino-carbazole) derivatives containing 1,10-phenanthroline and 8-hydroxyquinoline ligands: Synthesis, properties and application as ion sensors

As we know, excessive metal ions can even damage human health. Herein, two novel kinds of fluorescent sensing materials Poly(3-amino-carbazole) derivatives containing 1,10-phenanthroline and 8-hydroxyquinoline were synthesized and further applied to fluorescence detection for ions. The results show that Ni2+, Cu2+, and Pd2+ have excellent quenching effects on the fluorescence of Poly[9-(1,10-phenanthroline-2-yl)-9H-carbazol-3-amine] (PPNC), the LOD for these ions reaches 5.2 nM, 12.7 nM, 33.5 nM respectively. In the process of ion response, there is no shift of UV absorption peak, combined with IR spectra and theoretical calculation simulation, the quenching is considered to be caused by the coordination between metal ions and the second amine (–NH-) or 1,10-phenanthroline ligand of PPNC, which leads to the charge transfer from ligands to metal ions. In addition, an acid test was done for PPNC to verify and detect the presence of secondary amine (–NH-), and the results show that PPNC has good acid sensing ability which also supports the secondary amine (–NH-) structure. Finally, the paper test was performed on PPNC, indicating that PPNC has the potential for visual application.

Synthesis of 4-Amino-N-[2 (diethylamino)Ethyl]Benzamide Tetraphenylborate Ion-Associate Complex: Characterization, Antibacterial and Computational Study.

The 4-amino-N-[2 (diethylamino) ethyl] benzamide (procainamide)-tetraphenylborate complex was synthesized by reacting sodium tetraphenyl borate with 4-amino-N-[2 (diethylamino) ethyl] benzamide, chloride salt, and procainamide in deionized water at room temperature through an ion-associate reaction (green chemistry) at room temperature, and characterized by several physicochemical methods. The formation of ion-associate complex between bio-active molecules and/or organic molecules is crucial to comprehending the relationships between bioactive molecules and receptor interactions. The solid complex was characterized by infrared spectra, NMR, elemental analysis, and mass spectrometry, indicating the formation of ion-associate or ion-pair complex. The complex under study was examined for antibacterial activity. The ground state electronic characteristics of the S1 and S2 complex configurations were computed using the density functional theory (DFT) approach, using B3LYP level 6-311 G(d,p) basis sets. R2 = 0.9765 and 0.9556, respectively, indicate a strong correlation between the observed and theoretical 1H-NMR, and the relative error of vibrational frequencies for both configurations was acceptable, as well. HOMO and LUMO frontier molecular orbitals and molecular electrostatics using the optimized were used to obtain a potential map of the chemical. The n → π* UV absorption peak of the UV cutoff edge was detected for both configurations of the complex. Spectroscopic methods were structures used to characterize the structure (FT-IR and 1HNMR). In the ground state, DFT/B3LYP/6-311G(d,p) basis sets were used to determine the electrical and geometric properties of the S1 and S2 configurations of the title complex. Comparing the observed and calculated values for the S1 and S2 forms, the HOMO-LUMO energy gap of compounds was 3182 and 3231 eV, respectively. The small energy gap between HOMO and LUMO indicated that the compound was stable. In addition, the MEP reveals that positive potential sites were around the PR molecule, whereas negative potential sites were surrounding the TPB site of atoms. The UV absorption of both arrangements is comparable to the experimental UV spectrum.

A dual-signal fluorometric and colorimetric sensing platform based on gold-platinum bimetallic nanoclusters for the determination of β-galactosidase activity

Herein, a novel dual-signal sensing system for the determination of β-galactosidase (β-Gal) activity was established, which was based on a dual-emission probe assembled from gold-platinum bimetallic nanoclusters (Au–Pt NCs) and rhodamine B. Under the catalysis of β-Gal, 4-nitrophenyl β-D-galactopyranoside (PNPG) was rapidly hydrolyzed to generate p-nitrophenol (PNP), which has an obvious UV absorption peak at 400 nm. The hydrolyzed product PNP can quench the fluorescence of Au–Pt NCs effectively by inner filter effect (IFE), and PNP had no impact on the fluorescence of rhodamine B, which will change the emission intensity ratio of Au–Pt NCs and rhodamine B. Therefore, the ratiometric fluorescent and colorimetric dual-signal sensor based on Au–Pt NCs and rhodamine B was successfully constructed for sensitive detection of β-Gal activity. The linear detection range for the ratiometric fluorescence and colorimetric methods were 2.5–25 U/L and 15–55 U/L with detection limits of 1.2 U/L and 5.2 U/L, respectively. The developed assay method has been used for quantitative detection of β-Gal in spiked serum samples and showed good performance. And the detection platform has high reliability and excellent selectivity, which opens a new avenue for the further application of Au–Pt NCs in chemical sensing and biological analysis.

Green synthesis of gold nanoparticles via Capsicum annum fruit extract: Characterization, antiangiogenic, antioxidant and anti-inflammatory activities

Biological synthesis of gold nanoparticles (AuNPs) is gaining attention of researchers because of their varieties of biomedical applications. This study reported the novel, eco-friendly synthesis of AuNPs using dried fruit extract of Capsicum annum (C. annum). Biosynthesized gold nanoparticles (Ca-AuNPs) showed UV absorption peak at 540 nm and were found to be stable for up to three months. The nanoparticles were further characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FT-IR), Energy Dispersive X-ray Analysis (EDAX) and X-ray diffraction (XRD) analysis. The nanoparticles were spherical in shape with size range of 20–30 nm and zeta potential study confirmed the surface charge of -26.5 mV. The Ca-AuNPs were tested for anti-angiogenic activity using Chorioallantoic membrane (CAM) assay that implied a significant anti-angiogenic efficiency of Ca-AuNPs at 100 µg/mL concentration. The antioxidant activity of Ca-AuNPs studied by 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay was found to be significant with 86.0% radical scavenging activity. These nanoparticles also revealed anti-inflammatory activity at concentration range 100–1200 µg/mL with IC-50 value619.4 µg/mL. The present study includes synthesis of Ca-AuNPs by using phytoconstituents of plant material as reducing agents to efficiently exploit the biomedical applications of the nanoparticles.

Optical properties of carbon dots derived from table sugar via gamma irradiation

Gamma irradiation is the only approach for green environmental synthesis that does not require further waste treatment. Therefore, gamma irradiation was employed for carbon dot production at room temperature in this study. The table sugar was utilized as a raw material without the addition of any hazardous additives. Using sugar concentrations of 4, 20, and 40% by weight, carbon dots were produced using gamma irradiation at 25 kGy. The as-synthesized carbon dots were characterized using Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Utilizing UV-Visible absorption and fluorescence spectroscopy, the optical characteristics of carbon dots were investigated. The carbon dots as synthesized had a high UV absorption peak at 271 nm and adjustable fluorescence emission.

A dual-mode ratiometric fluorescence and smartphone-assisted colorimetric sensing platform based on bifunctional Fe,Co-CQD for glucose analysis at physiological pH

Diabetes is a common and fatal chronic metabolic disease characterized by hyperglycemia, and thus monitoring blood glucose level is essential for early screening and timely control of disease. Herein, we have prepared the bifunctional iron and cobalt co-doped carbon quantum dot (Fe,Co-CQD) with good optical properties and peroxidase-mimetic catalytic activity toward specific substrate o-phenylenediamine (OPD) under alkaline condition. Glucose oxidase (GOx) specifically catalyzes the oxidation of glucose into H2O2, and Fe,Co-CQD subsequently triggers a reaction between H2O2 and OPD to form yellow product DAP with a distinct UV absorption peak at 420 nm. Simultaneously, the generated DAP also appears a well-defined fluorescence signal at 555 nm, which can suppress the intrinsic fluorescence peak of Fe,Co-CQD (439 nm) owing to the inner filter effect (IFE). Based on this principle, a dual-mode ratiometric fluorescence and colorimetric sensing platform has been constructed for glucose analysis at physiological pH, which reveals the advantages of excellent accuracy, high throughput, simple operation, and low cost. More importantly, a smartphone-assisted colorimetric sensing system based on a portable visual detection kit and a 3D printing smartphone-based device has been constructed, which enables on-site detection of glucose in complex serum samples without laboratory instruments, indicating its potential practical application prospect.

Citrate-Capped AuNP Fabrication, Characterization and Comparison with Commercially Produced Nanoparticles

Gold nanoparticles (AuNPs) were synthesized using citrate reduction, also known as the Turkevich method. The AuNPs were compared with the commercially available product and later subjected to characterization. The AuNPs were 13 nm in diameter with a 2.7 × 108 M−1cm−1 extension coefficient. The calculated concentration was 5.1 nM through the Beer–Lambert law using UV–vis absorbance spectra. Further detailed characterization was applied, such as scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), elemental analysis using electro and DLS instruments, energy-dispersive X-ray spectroscopy (EDS), XRD, and Zeta potential. The synthesized AuNPs had a higher UV-absorbance peak of 0.93 in comparison to commercially available nanoparticles at 5.8 identical conditions. The characterization confirmed successful fabrication of colloidal-citrate-capped AuNPs and their dispersed and aggregated state with induced salt concentration. The shape and morphology were confirmed through XRD, showing a face-centered cubic lattice of {111}, confirmed at 38.1 round shape, and a crystalline lattice. AuNPs tend to be applied in sensing, detection, drug delivery, pharmaceuticals, and other applications in the environment and materials. Other applications include environmental contaminant detection, colorimetric sensors, antimicrobial applications, biosensing and drug delivery, tissue engineering, nanomedicines, optoelectronics, and catalysts.

Augmented anticancer effect and antibacterial activity of silver nanoparticles synthesized by using Taxus wallichiana leaf extract.

Taxus wallichiana is an evergreen tree species found in the Himalayan region of Pakistan. The tree possesses important secondary metabolites such as Taxol that has been implicated in treating breast, ovarian and colon cancer. Therefore keeping in view the importance of this plant species, silver nanoparticles were synthesized using Taxus wallichiana aqueous leaf extract and evaluated for their anti-bacterial and anti-cancer properties. Silver (Ag) nanoparticles (NPs) were characterized for their optical, morphological and structural features using techniques such as UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) and were evaluated for their antibacterial activity and anti-cancer activity using U251 cell line. The study showed that the UV-absorbance peak of Ag2O NPs at 450 nm shifted to 410 nm, affirming the formation of leaf extract Ag NPs. Similarly structural studies revealed the crystalline nature of the cubic structure of the Ag crystal with an average crystallite size of 29 nm. FTIR analysis exhibited the existence of different functional elements including O-H and N-H and phenolic groups. Non-spherical glomerular shaped Taxus wallichiana Ag NPs were observed from SEM studies and EDX profile showed Ag as the main element along with constituent of biological origin. The synthesized Ag NPs showed significant antibacterial activity against Salmonella typhi, and Staphylococcus aureus. The cytotoxic activity of Ag NPs on U251 brain cancer cells showed a synergistic effect with 10 ug/mL concentration after 48 and 72 h incubation based on cell viability assay indicating promising glioblastoma drug potential.

Zn-ZrMOF containing Lewis acid-base catalytic sites for hydrolysis and visual detection of profenofos

A colorimetric method for the catalysis hydrolysis of profenofos (C11H15BrClO3PS) was designed based on Zn-ZrMOF. Zn-ZrMOF has the catalytic activity of organophosphorus hydrolase and contains Lewis acid-base catalytic sites, which can catalyze the cleavage of P-O bond of profenofos to obtain hydrolysate (4-bromo-2-chlorophenol). As a phenolic substance, 4-bromo-2-chlorophenol can react with the chromogenic agent 4-aminoantipyrine (4-AAP) and produce a pink product (4-((3-chloro-4-oxocyclohexa-2,5-dien-1-ylidene)amino)− 1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one) in the presence of oxidizer K3[Fe(CN)6] under the weak alkalinity. The pink product has a strong UV absorption peak at 508 nm. The solution color gradually changed from colorless to pink with the increase of the concentration of profenofos. The concentration of profenofos could be semi-quantitatively analyzed by naked eye. The linear range of this method was 0.01–1000 μg mL−1, and the detection limit was 6.33 × 10−3 μg mL−1. Additionally, the method has good selectivity and accuracy for the determination of profenofos. This study provides a feasible strategy for the design of a metal-organic framework material with organophosphorus hydrolase-like catalytic activity for the determination of profenofos in vegetables.

Physicochemical and functional properties of the muscle protein fraction of Hypomesus olidus.

The physicochemical and functional properties of myofibrillar protein (MP), sarcoplasmic protein (SP), and myostromin (MY) in Hypomesus olidus muscle were evaluated and reported in this study. These fractions are rich in Glu. Three proteins exhibited significantly different morphologies, colors, and particle sizes. The main protein bands of MP, SP, and MY are 15-220kDa, 26-60kDa, and 15-245kDa, respectively. In particular, MP is more hydrophobic. Three proteins exhibited a maximum UV absorption peak at 270nm, and all amide I secondary structures were shown to be composed of repetitive units (e.g., α-helices and β-sheets). The three proteins demonstrated a predominantly amorphous halo, with Td values of 52.22°C, 59.16°C, and 58.09°C. Regarding their properties in water/oil absorption, emulsification, and foaming, MP is the most preferred, followed by SP and MY. In conclusion, Hypomesus olidus muscle proteins are novel and potential functional nutrition ingredients for the food industry.

Separation of the overlapped humic acid and BGP characteristic peaks using two-dimensional correlation fluorescence-UV-vis spectroscopy

Fluorescence spectroscopy has been widely used to detect polycyclic aromatic hydrocarbons (PAHs) in the environment. However, the interference of coexisting humic acids (HA) in the environment poses a great challenge to the qualitative and quantitative detection of PAHs using fluorescence spectroscopy. In this study, the spectral properties of benzo [ghi] perylene (BGP) and HA were investigated based on fluorescence and UV–vis spectroscopy combined with two-dimensional (2D) correlation analysis. Under the external disturbance of HA concentration, the homo-2D (fluorescence, UV–visible) correlation and hetero-2D fluorescence-UV–visible correlation spectral characteristics of the mixed samples of HA and BGP were studied, and the effect of HA on the fluorescence of BGP was investigated. It can be inferred that the fluorescence peak at 478 nm come from BGP, and the fluorescence peaks at 442 nm and 533 nm, UV absorption peak at 233 nm come from HA. Meanwhile, asynchronous two-trace two-dimensional (2T2D) fluorescence correlation slice spectra at 533 nm were obtained. The slice spectral intensity at 478 nm was extracted to quantify the BGP concentration in mixture. The results showed that the slice spectral intensity and BGP concentration had a good linear relationship with the coefficient of determination R2 = 0.96. This research provides a way to further study the separation method of HA and PAHs or explore the correction method of the effect of HA on PAHs.