UV-vis Absorption Spectroscopy Research Articles

Surfactant Composition Dependent Evolution of Electronic/Structural Properties of P3HT Nanoparticle Colloids Synthesized via Mini-Emulsion Technique

: This study investigates the influence of surfactant (sodium dodecyl sulfate, SDS) concentration on the size and optoelectronic properties of poly(3-hexylthiophene) (P3HT) nanoparticles (NPs) synthesized via the mini-emulsion technique. P3HT NPs were fabricated with varying SDS concentrations. The size dependent optoelectronic properties, including the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) levels, were analyzed through photoelectron spectroscopy in air, UV-Vis absorption spectroscopy and cyclic voltammetry. A clear trend of decreasing NP size with increasing SDS concentration was observed. Higher SDS levels resulted in smaller NPs with enhanced pi-pi stacking and shorter conjugation lengths. This structural change led to a noticeable shift in HOMO and LUMO levels, indicating a direct correlation between surfactant concentration and the electronic properties of the P3HT NPs. The absorption spectra revealed a decrease in the A0-0/A0-1 ratio with smaller NP size, suggesting a transition towards more pronounced H-aggregate characteristics. As the size of the P3HT NPs decreases, there is a notable increase in H-aggregate formation. This increase can be attributed to enhanced interchain interactions between the polymer chains. In smaller NPs, the surface area-to-volume ratio is higher, leading to more significant interactions between adjacent polymer chains. These interactions promote the formation of H-aggregates, characterized by their interchain pi-pi stacking, which differs from the intrachain coupling observed in J-aggregates.

Strategies for Effective Degradation of Methyl Orange Dye in Aqueous Solution via Electrochemical Treatment with Copper/Graphite Electrodes

This study investigated the electrochemical degradation of methyl orange dye (MO) in aqueous solution using copper/graphite electrodes as anode and cathode respectively. The process parameters such as electrolyte concentrations, current density, pH and temperature were analyzed. The results proved that copper/graphite electrodes were effective for MO degradation and the reaction followed the first-order kinetic model. The degradation efficiency decreased with increasing MO concentration and increased steadily with current density. The pH trend with degradation efficiency was pH 9 (98%) > pH 7 (96%) > pH 3 (77%) after 70 min of electrolysis time, which shows that the alkaline conditions favoured the degradation process. Fourier transform infrared spectroscopy (FTIR) and UV–Vis absorption spectroscopy confirmed the dye degradation process, with the formation of degradation intermediates. The FTIR results revealed that the oxidative degradation of MO may be initiated at the N=N azo bond, which was confirmed by quantum chemical modelling of the electronic structure parameters of MO.

Composite membranes from bio-inspired catechol-amine coatings for pervaporation desalination

Compared with reverse osmosis, pervaporation is less influenced by the osmosis pressure of the feed solution, which endows it as an attractive desalination technology. Many researches focus on developing high-performance pervaporation desalination membranes. Bio-inspired polyphenol coatings are versatile tools for engineering membrane surfaces. Here, catechol-amine chemistry was the first time applied to construct dense composite pervaporation desalination membranes via a stepwise coating method. Tannic acid (TA) and polyethyleneimine (PEI) were chosen as typical materials. Fabrication parameters, including TA and PEI concentrations in the coating solution, pH, and thermal annealing, are crucial to the desalination performance of the resulting membranes. The TA-PEI interactions were studied by the UV–Vis absorption spectroscopy method. The membrane prepared at optimal conditions exhibits excellent desalination performance. The water flux was 43 kg/(m2·h) at 50 °C for the feed of 3.5 wt% NaCl solution (95 kg/(m2·h) at 70 °C). The intrinsic hydrophilicity of the selective layer material ensures the membrane processes of good antifouling performance. This work demonstrates the possibility and potential of applying bio-inspired catechol-amine chemistry to prepare pervaporation desalination membranes.

Teaching Experimental Instrumental Analytical Chemistry Are we forming professionals, training operators or illuding students (and ourselves)?

Teaching Experimental Instrumental Analytical Chemistry Are we forming professionals, training operators or illuding students (and ourselves)?

Development of chitosan by using a zeolite‐supported CaO derived from waste chicken eggshell to remove Acid Red 1 dye from the aqueous solution

AbstractZSM‐5 zeolite modified with acetic acid eggshell and chitosan was impregnated in three distinct proportions. As nanocomposites (NCs), the purpose of the composites was to adsorb Acid Red 1 dye (AR‐1) from an aqueous solution. The characterization of chitosan@CaO/zeolite NCs included (CHT)1@(CaO/ZT)1, (CHT)1.5@(CaO/ZT)1, and (CHT)1@(CaO/ZT)1.5, as determined by FTIR, XRD, EDX, BET, TGA, and UV–Visible absorption spectroscopy. In a bulk system, the adsorption of the AR‐1 dye onto (CHT)1@(CaO/ZT)1.5 was analyzed in terms of solution temperature, pH, contact time, and NCs dosage. The most favorable parameters for achieving efficient dye adsorption were: a pH of 2, an adsorbent dosage of 0.05 g/25 mL of dye solution, and 20 mg/L of dye concentration at 22°C temperature. The reaction reached equilibrium after 120 min. The estimated adsorption efficiency of the AR‐1 dye by the prepared NCs is 99.70%. The mechanism by which the dye was sequestered onto (CHT)1@(CaO/ZT)1.5 was exothermic. The correlation coefficient (R2) for the pseudo‐second‐order adsorption kinetic model held true at different temperatures with a value of 0.99, indicating that the model accurately described the chemical interaction between the adsorbent and Acid Red (AR‐1). Adsorption processes are characterized as exothermic, feasible, and spontaneous when the Gibbs free energy (ΔG°) and enthalpy (ΔH°) changes have negative values, respectively. It was determined that the Langmuir model best described the isotherm behavior of AR‐1 dye adsorption onto (CHT)1@ (CaO/ZT)1.5. Under ideal conditions, the surface was found to be homogeneous and had a maximum adsorption capacity (qm) of 84.03 mg/g.

Simultaneous synthesis of carbon quantum dots and porous carbon using one step hydrothermal method for supercapacitor applications

The present work reports a one-step hydrothermal carbonization process used to simultaneously produce carbon quantum dots and porous carbon. The synthesized materials were characterized by using a Fourier transform infrared spectrometer (FT-IR) to study the chemical interactions, the optical properties were studied with the help of UV-visible absorption spectroscopy, and the morphology analysis of CQDs and porous carbon was examined using FESEM, in which spherical morphology confirms the formation of CQDs, while XRD confirms the amorphous nature of the porous carbon. The application of CQDs and porous materials is evaluated as a supercapacitor material by using the cyclic voltammetry technique. The specific capacitance of porous carbon was 161.33 Fg−1 at 0.01mVs−1 scan rate. This makes CQDs and porous carbon a promising candidate for applications in energy storage devices such as supercapacitors.

Insights into the binding of buspirone to human serum albumin using multi-spectroscopic and molecular docking techniques

Buspirone is an anxiolytic drug that plays a significant role in managing anxiety disorders and alleviating their symptoms as well. Several techniques were utilized to study the interaction between buspirone and human serum albumin under physiological conditions, including UV–vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism, Fourier transform infrared spectroscopy (FT-IR), equilibrium dialysis, and molecular docking. The results of this study demonstrated that buspirone quenched the intrinsic fluorescence of human serum albumin through a mixed mechanism. Moreover, the binding constants (Kb), the quenching constants (Ksv), and thermodynamic parameters were calculated at various temperatures. The binding process of buspirone to human serum albumin showed a cooperative binding pattern, confirmed by the Scatchard diagram and Hill coefficient. Molecular docking results showed that buspirone interacted with the IIA, IIIA, and IIB subdomains of human serum albumin and slightly changed its conformation. It was also found that hydrophobic forces played a major role in this interaction. This study consequently proves that BSH as a drug can be transported by blood albumin. Additionally, due to its ratiometric response in absorbance upon binding to a biological target, HSA can be used as a molecular probe to follow biomolecular interactions.

High‐Performance of Self‐Powered UV–Visible CdS (PVP)/PbI2 Heterojunction Photodetector

Herein, the Polyvinyl pyrrolidone (PVP)‐assisted CdS/PbI2 heterojunction UV–visible photodetector is constructed by the sol–gel spin coating method. The X‐ray diffraction, scanning electron microscopy, and energy dispersive spectrometer demonstrate the synthesis and successful complexation of PVP, CdS, and PbI2. The UV–visible absorption spectroscopy and UV photoelectron spectroscopy measurements of CdS and PbI2 are carried out to prove that the CdS and PbI2 form a type II heterojunction. Compared with pure CdS film photodetector, the CdS (PVP)/PbI2 heterojunction photodetector has self‐powered characteristics, and exhibits excellent photoconductivity in the UV–visible with higher switching ratios, detection rates, and faster response times of 1.1 × 105, 9.77 × 1011 Jones, and 20 ms, respectively, which has great potential in the field of UV–visible self‐powered photodetector.

Fabrication of flexible paper-based conducting molecularly imprinted polymer as analytical devices: Electrochemically assisted solid phase microextraction and selective flexible sensor for determination of naproxen

An electrochemical method is presented for the preparation of paper-based conductive molecular imprinted polymer (CMIP) film as a recognition element of a sensor and a selective absorber in separation methods. The paper became conductive by chemically incorporating polypyrrole (PPy) doped with anion dopant. The effects of the anion dopant and oxidant type on the conductivity of the modified paper were studied. Afterward, a CMIP film based on PPy and an anionic drug as a template was electrochemically synthesized on conductive paper surface, which was then utilized as a selective sorbent for electrochemically assisted solid phase microextraction (EC-SPME) and a recognition element in fabricating flexible drug-selective sensor. Factors affecting the performance of the paper-based EC-SPME device were studied in naproxen (NAP) analysis. All quantitative analytical parameters in the EC-SPME device were obtained by UV–vis absorption spectroscopy. Under the optimal conditions, linearity was achieved within the range of 2.0 × 10−7–2.0 × 10−5 mol/L with determination coefficient (R2 = 0.99) and the limit of detection (LOD) was 0.6 × 10−7mol/L. Moreover, a fabricated paper-based NAP-selective sensor, showed Nernstian response slopes of −61.6 ± 0.5 mV decade−1 over the linear range of 4.0 × 10−7–1.0 × 10−2 mol/L and LOD was 2.0 × 10−7 mol/L. The applicability and efficiency of the paper-based analytical devices were investigated for NAP determination as a model drug in human serum samples. The recoveries were obtained in the range of 90.0–103.0 %. Accordingly, paper-based CMIPs were found to be a novel fabrication method for efficient, selective, flexible and cost-effective material for analytical devices.

Synthesis of inorganic/organic hybrid-shell antibacterial polyurea microcapsules loaded with Ag/TiO2 nanoparticles

Silver/titanium dioxide (Ag/TiO2) nanoparticles, renowned as effective inorganic antibacterial agents with a wide spectrum of activity and minimal resistance induction, encounter challenges when incorporated into organic substrates. This integration often leads to particle aggregation, resulting in a substantial reduction in antibacterial efficacy. This study devised a novel approach involving loading Ag/TiO2 nanoparticles onto polyurea microcapsules (PUMC), forming hybrid-shelled microcapsules (Ag/TiO2-PUMC) using silane coupling agents. The preparation of polyurea microcapsules offers the advantages of rapid synthesis and mild reaction conditions, facilitating industrial-scale production. Additionally, loading Ag/TiO2 nanoparticles onto polyurea microcapsules helps alleviate the aggregation issue, and the organic nature of polyurea microcapsules enhances compatibility with organic substrates. Characterization techniques, including SEM, TEM, FTIR, XRD, UV–visible absorption spectroscopy, EPR and thermogravimetric analysis, were employed to confirm the successful grafting of Ag/TiO2 nanoparticles onto the PUMC. A comparative analysis between the two silane coupling agents, KH550 and KH792, revealed that the dual amino-functional silane coupling agent, KH792, played a pivotal role in chain extension during the microcapsule self-polymerization process. The antibacterial activity of the Ag/TiO2-PUMC was evaluated against Escherichia coli and Staphylococcus aureus. Remarkably, the hybrid-shelled microcapsules exhibited outstanding antibacterial efficacy, achieving a 99.99% antibacterial rate within just 0.5 hours. This performance surpassed unmodified Ag/TiO2 nanoparticles, highlighting the enhanced antibacterial efficacy of the hybrid-shelled microcapsule structure. This study presents a successful synthesis strategy for inorganic/organic hybrid-shelled antibacterial microcapsules and provides valuable insights for refining inorganic antibacterial agents. The demonstrated approach holds substantial promise for advancing the field of organic antibacterial materials.

Novel fluorescent probes based on sulfur and nitrogen co-doped carbon dots for determination of three N-substituted phenothiazine derivatives in dosage forms

In the current work, sulfur and nitrogen co-doped carbon dots (S,N-CDs) as simple, sensitive, and selective turn-off fluorescent nanosensors were utilized for analysis of three phenothiazine derivatives, including acetophenazine (APZ), chlorpromazine (CPH), and promethazine (PZH). S,N-CDs were synthesized through a green one-pot microwave-assisted technique using widely available precursors (thiourea and ascorbic acid). HRTEM, EDX, FTIR spectroscopy, UV–Vis absorption spectroscopy, and fluorescence spectroscopy were used to characterize the as-synthesized CDs. When excited at 330 nm, the carbon dots produced a maximum emission peak at 410 nm. The cited drugs statically quenched the S,N-CDs fluorescence as revealed by the Stern-Volmer equation. The current method represents the first spectrofluorimetric approach for the determination of the studied drugs without the need for chemical derivatization or harsh reaction conditions. The importance of the proposed work is magnified as the cited drugs do not have any fluorescent properties. The fluorescence of the developed sensor exhibited a linear response to APZ, CPH, and PZH in the concentration ranges of 5.0–100.0, 10.0–100.0, and 10.0–200.0 μM with detection limits of 1.53, 1.66, and 2.47 μM, respectively. The developed fluorescent probes have the advantages of rapidity and selectivity for APZ, CPH, and PZH analysis in tablets with acceptable % recoveries of (98.06–101.66 %). Evaluation of the method's greenness was performed using the Complementary Green Analytical Procedure Index (ComplexGAPI) and Analytical GREEnness metric (AGREE) metrics, indicating that the method is environmentally friendly. Validation of the proposed method was performed according to ICHQ2 (R1) guidelines.

Rhodamine B Hazardous Dye Removal via Adsorption Using Hg(II) Coordination Polymer

Herein, we have reported the Hg(II) coordination polymer ,(Hg-CP), formulated {[Hg(L)](Cl2)](CH3CN)2}n, behaved as adsorbent against Rhodamine B dye stuff. UV-Vis absorption spectroscopy was used to conduct dye adsorption investigations on coordination polymers. Adsorption experiments were carried out in acidic (pH=3) and neutral (pH=6) media and the results showed that the compound removed the cationic Rhodamine B from water. In acidic media, the adsorption capacity of the Hg-CP was more than neutral media. Also, Hg-CP could selectively adsorb Rhodamine B dye from the Rhodamine B/Methyl orange dye mixture. The colour of the Hg-CP was white before adsorption, whereas it changed after adsorption as Rhodamine B adhered to the surface of Hg-CP.

Structural, spectroscopic, DFT studies, Hirshfeld surface analysis and antibacterial activity of Z-3-(4-bromophenyl)-3-chloroacrylaldehyde

The present paper describes the single-crystal X-ray structure of Z-3-(4-bromophenyl)-3-chloroacrylaldehyde (BCA). Hirshfeld Surface analysis was performed, providing insight into intermolecular interactions for the first time. The compound crystalizes in the monoclinic system with a space group P21/c and unit cell dimensions of a =3.9327(4) Å, b=18.5517(19), c=12.2749(14) and V=894.77(16)Å3. Z-3-(4-bromophenyl)-3-chloroacrylaldehyde was characterized using 13C and 1H NMR spectroscopy, and its thermal stability assessed with a thermogravimetric analyzer. Optical properties were investigated through UV-Visible absorption and emission spectroscopy. Density Functional Theory (DFT) calculations were performed using B3LYP theory with a basis set of SDD. HOMO-LUMO calculations, conceptual DFT and its global reactivity descriptors like hardness, electronegativity and electrophilicity of molecule were studied using G16W software. The energy gap of 4.17eV obtained from HOMO-LUMO molecular orbital energy shows that the compound is hard, stable and reactive. Further, Z-3-(4-bromophenyl)-3-chloroacrylaldehyde also exhibited significant antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with a zone of inhibition of 13 ± 1 mm against E. coli and 14 ± 1 mm against S. aureus and the MIC value was found to be 0.55 mg/mL against S. aureus and 1.1 mg/mL against E. coli. The integration of experimental and theoretical approaches in this study enhances the understanding of the versatile applications of BCA across various fields.

Novel short Agave americana based biocomposite and nanobiocomposites for automotive applications

Short fibers of Agave Americana (AA) was extracted from its plant leaf, was chemically treated with Ac2O, HCOOH, H2O2, KMnO4 and NaOH, and then characterized by Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), thermo-gravimetric/differential thermo-gravimetric (TGA/DTG), and field emission-scanning electron microscopy (FE-SEM). PVA stabilized copper nanoparticles from chemical reduction method was characterized using field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDAX), powder X-ray diffraction (PXRD), Dynamic light scattering analysis (DLS), UV–visible absorption spectroscopy, Fourier Transform infrared (FT-IR) spectroscopy and Thermogravimetric analysis/differential thermogravimetry (TGA/DTG). Bio-composites (AA + Polyester Resin (PE) and hybrid nano bio-composites (AA + Polyester Resin (PE) + Cu) were prepared from the untreated and treated AA fibers and further characterized. The synergistic effect of chemical treatment on morphological (SEM), thermal (TGA/DTG), mechanical properties (flexural, tensile, impact and compressive strength) followed by % water absorption were examined. The average surface roughness values (Ra) of chemical treated fiber was identified to be in decreasing manner along with compression strength of biocomposite in the order of untreated (10.74 μm, 44.01 MPa) > NaOH (8.55 μm, 45.07 MPa) > HCOOH (3.49 μm, 24.10 MPa) Ac2O (3.24 μm, 22.10 MPa) > H2O2 (2.51um, 17.9 MPa) > KMnO4 (1.52 μm, 15.1 MPa) treated fibers. Subsequently, the addition of 2s@PVA led to reverse the order namely, the compressive strength of the bionanocomposites were Untreated (10.74 μm, 9.0 MPa) < NaOH (8.55 μm, 0.1 MPa) < HCOOH (3.49 μm, 3.6 MPa) < Ac2O (3.24 μm, 7.6 MPa) < H2O2 (2.51um, 13.3 MPa) < KMnO4 (1.52 μm, 44.1 MPa) treated fibers. Similarly, the biocomposite where the fibres were treated with NaOH, HCOOH were more rough and had, good interconnection between fiber/PE matrix along with enhanced mechanical properties. On addition of nanobiocomposite, only KMnO4 treated fiber composite possed significant mechanical properties. Therefore, mixing CuNPs@PVA with KMnO4 treated fibers led to significant boost to the mechanical properties and minimised the % water absorption properties when compared to the untreated AA/PE biocomposites. The KMnO4 treatment of the AA fiber and addition of copper nanoparticles caused the enhancement of thermal properties, tensile strength and flexural strength. But, these nanobiocomposites were observed to have low impact strength; while, H2O2 treated nanobiocomposites had highest impact strength. The chemical treatment of the AA fiber with NaOH, Ac2O and KMnO4 developed the water resistance of the respective biocomposites. All the nanobiocomposites with chemically treated AA fibers (except Ac2O) were found to have high water resistance. So, they can be used in automotive industry for non-structural applications.

The Role of PbCoS Quantum Dots in Improved Photovoltaic Efficiency

&lt;p&gt;The quest for efficient, sustainable solar energy solutions has propelled the exploration of novel materials with enhanced photovoltaic properties. This study delves into the synthesis, characterization, and photovoltaic application of cobalt-doped lead sulfide (PbCoS) quantum dots (QDs) deposited on titanium dioxide (TiO2) substrates. Employing a hot-injection method, we synthesized PbCoS QDs and characterized their structural, compositional, and optical properties using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and UV-Visible absorption spectroscopy. The QDs demonstrated a cubic crystal structure with an average size of 20.12 nm and exhibited a direct band gap of 1.91 eV, indicative of quantum confinement effects and improved absorption in the visible spectrum. The photovoltaic performance of quantum dot-sensitized solar cells (QDSSCs) incorporating PbCoS QDs was assessed through current density-voltage (J-V) measurements, revealing a power conversion efficiency (PCE) of 2.17%. This efficiency highlights the potential of PbCoS QDs to enhance the performance of QDSSCs, partly attributed to the impact of cobalt doping on the electronic structure and photovoltaic properties of the material. The study identifies gaps in current research, such as the optimization of cobalt doping levels and the exploration of interface engineering between QDs and substrates, pointing towards future directions for enhancing the efficiency and applicability of PbCoS-based photovoltaic devices.&lt;/p&gt;&#x0D;

Fabrication of ZnO Scaffolded CdS Nanostructured Photoanodes with Enhanced Photoelectrochemical Water Splitting Activity under Visible Light.

CdS, characterized by its comparatively narrow energy band gap (∼2.4 eV), is an appropriate material for prospective use as a photoanode in photoelectrochemical water splitting. Regrettably, it encounters several obstacles for practical and large-scale applications, including issues such as bulk carrier recombination and diminished conductivity. Here, we have tried to address these challenges by fabricating a novel photoelectrode (ZnO/CdS) composed of one-dimensional ZnO nanorods (NRs) decorated with two-dimensional CdS nanosheets (NSs). A facile two-step chemical method comprising electrodeposition along with chemical bath deposition is employed to synthesize the ZnO NRs, CdS NSs, and ZnO/CdS nanostructures. The prepared nanostructures have been investigated by UV-visible absorption spectroscopy, X-ray diffraction, Raman spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy. The fabricated ZnO/CdS nanostructures have shown enhanced photoelectrochemical properties due to the improvement of the semiconductor junction surface area and thereby enhanced visible light absorption. The incorporation of CdS NSs has been further found to promote the rate of the charge separation and transfer process. Subsequently, the fabricated ZnO/CdS photoelectrodes achieved a photocurrent conversion efficiency 3 times higher than that of a planar ZnO NR photoanode and showed excellent performance under visible light irradiation. The highest applied bias photon-to-current conversion efficiency (% ABPE) of about ∼0.63% has been obtained for the sample with thicker CdS NSs on ZnO NRs with a photocurrent density of ∼1.87 mA/cm2 under AM 1.5 G illumination. The newly synthesized nanostructures further demonstrate that the full photovoltaic capacity of nanomaterials is yet to be exhausted.

Mononuclear η6-arene ruthenium(II) complexes with pyrazolyl-pyridazine ligands: synthesis, CT-DNA binding, reactivity towards glutathione, and cytotoxicity.

Organometallic η6-arene ruthenium(II) complexes with 3-chloro-6-(1H-pyrazol-1-yl)pyridazine (Ru1, Ru2, and Ru5) and 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine (Ru3-4) N,N' heterocyclic and η6-arene (cymene (Ru1-4) or toluene (Ru 5)) have been synthesized. The ruthenium(II) complexes have common "three-legged piano-stool" pseudo-octahedral structures known for half-sandwich complexes. Evolution of their UV-Visible absorption spectra in PBS buffer or DMSO over 24h confirmed their good solvolysis stability. Titrations of the complexes with the calf thymus DNA (CT-DNA) were monitored using UV-Visible absorption and fluorescence spectroscopies. The complexes interact moderately with CT-DNA and their binding constants are in the order of 104M-1. Competitive binding of the complexes to a DNA-Hoechst 33,258 depicted competitive displacement of Hoechst from DNA's minor grooves. These complexes bind to glutathione forming GSH-adducts through S coordination by replacement of a halide, with the iodo-analogues having higher binding constants than the chloro-complexes. Cyclic voltammograms of the complexes exhibited one electron-transfer quasi-reversible process. Trends in the molecular docking data of Ru1-5/DNA were similar to those for DNA binding constants. Of the five, only Ru1, Ru3 and Ru5 showed some activity (moderate) against the MCF-7 breast cancer cells with IC50 values in the range of 59.2-39.9 for which Ru5 was the most active. However, the more difficult-to-treat cell line, MDA-MB 231 cell was recalcitrant to the treatment by these complexes.

Gold nanoparticles spectral CT imaging and limit of detectability in a new materials contrast-detail phantom

This study involves the synthesis, characterization, and spectral photon counting CT (SPCCT) imaging of gold nanoparticles tailored for enhancing the contrast of small cancer lesions. We used the modified Turkevich method to produce thiol-capped gold nanoparticles (AuNPs) at different concentrations (20, 15, 10, 5, 2.5, 1.25, 0.6 mg/ml). We thoroughly characterized the AuNPs using Transmission Electron Microscopy (TEM), X-ray diffraction spectroscopy (XRD), Dynamic Light Scattering (DLS), and UV–visible absorption spectroscopy. To assess the AuNPs contrast enhancing performance, we designed and built a new material contrast detail phantom for CT imaging and determined the minimum detectable concentrations of AuNPs in simulated lesions of small diameters (1, 2, 3, and 5 mm). The synthesized AuNPs are spherical with an average size of approximately 20 ± 4 nm, with maximum UV absorption occurring at 527 nm wavelength, and exhibit a face-centered cubic structure of gold according to XRD analysis. The synthesized gold nanoparticles demonstrated high contrast in SPCCT, suggesting their potential as contrast agents for imaging cancer tissues. The AuNPs image contrast was directly proportional to the AuNPs concentration. We are the first to determine that the lowest visually distinguishable contrast was achieved at a gold concentration of 5 mg/ml for a 2 mm simulated lesion. For 1 mm size lesion the smallest visible concentration was 10 mg/ml. This newly developed phantom can be used for determining the minimal concentration required for various high-Z nanoparticles to produce detectable contrast in X-ray imaging for small-size simulated lesions.

Investigation of structural, morphological, and ionic conduction behaviour of Na+ substituted trimeric strontium silicate Sr3–3xNa3xSi3O9-δ (0.00 ≤ x ≤ 0.20)

Extensive research has been carried out to search new electrolytes for Solid Oxide Fuel Cells (SOFCs) in order to reduce their operating temperature in the intermediate temperature range (500 ̊C < t < 800 ̊C) for wide commercialization. Recently, alkali doped strontium silicates materials have been reported to show adequate ionic conductivity in the intermediate temperature range. Hence, in the present work, we have tried to synthesize trimeric Sr3–3xNa3xSi3O9-δ (0.00 ≤ x ≤ 0.20; SNS) system and did a comprehensive study on this system to examine its applicability as a solid electrolyte for electrochemical devices such as IT-SOFCs. The SNS system was prepared via solid state reaction route and characterized by means of XRD, FT-IR and Raman spectroscopy to authenticate the structural phase formation and to gather its spectroscopic traits. The optical Energy band gap of the system was calculated by means of UV-Visible absorption spectroscopy. Surface morphology, microstructure and elemental confinement of the system was examined via Scanning Electron Microscopy (SEM) and Energy dispersive spectroscopy (EDX) techniques. The ionic transport study of the system has been conducted via AC conductivity analysis and Electrical Impedance Spectroscopy (EIS) technique. The highest total conductivity ∼ 0.46×10−2 Scm−1 at 650 ºC was found for the composition Sr2.40Na0.60Si3O9-δ thru EIS method.

Confinement Effect in Metal-Organic Framework Cu3(BTC)2 for Enhancing Shape Selectivity of Radical Difunctionalization of Alkenes.

The radical difunctionalization of alkenes plays a vital role in pharmacy, but the conventional homogeneous catalytic systems are challenging in selectivity and sustainability to afford the target molecules. Herein, the famous readily available metal-organic framework (MOF), Cu3(BTC)2, has been applied to cyano-trifluoromethylation of alkenes as a high-performance and recyclable heterogeneous catalyst, which possesses copper(II) active sites residing in funnel-like cavities. Under mild conditions, styrene derivatives and various unactivated olefins could be smoothly transformed into the corresponding cyano-trifluoromethylation products. Moreover, the transformation brought about by the active copper center in confined environments achieved regio- and shape selectivity. To understand the enhanced selectivity, the activation manner of the MOF catalyst was studied with control catalytic experiments such as FT-IR and UV-vis absorption spectroscopy of substrate-incorporated Cu3(BTC)2, which elucidated that the catalyst underwent a radical transformation with the intermediates confined in the MOF cavity, and the confinement effect endowed the method with pronounced selectivities.