UV-vis Absorption Spectroscopy Research Articles

The Role of PbCoS Quantum Dots in Improved Photovoltaic Efficiency

<p>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.</p>

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.

Nanocomposite-Supported Polymeric Composites Prepared with Different Deposition Bases: Characterization and Application in X-ray Shielding

This study deals with the preparation of magnetite nanoparticles (NPs) via a coprecipitation method using several precipitation bases: binary precipitator (NH4OH), mono precipitator (NaOH), and weak precipitator (Ca(OH)2). The prepared magnetite NPs were identified using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, surface area analysis, magnetic properties, Fourier-transformed infrared spectra (FT-IR), and ultra-violet UV–visible spectra. As a result, the phases of the produced magnetite NPs were unaffected by the use of various bases, but their crystallite sizes were affected. It was found that the binary base provided the smallest crystallite size, the mono base provided an average size, and the weak base provided the largest crystallite size. The UV–visible absorption spectroscopy investigation revealed that the absorption and the energy gap rose with a reduction in nanoparticle size. The prepared magnetite NPs were used to manufacture polymeric-based nanocomposites employed as protective shields from low-energy X-rays that are light in weight. These samples were identified using XRD, atomic force microscopy (AFM), and FT-IR spectroscopy. The crystallite size was slightly larger than it was in the case of magnetite NPs. This is consistent with the results of AFM. The interference between the two phases was observed in the results of the FT-IR spectra. The effects of the size of the magnetite NPs on the attenuation tests, linear attenuation coefficient, mass attenuation coefficient, half-value layer, and mean free path were investigated. The results showed that the efficiency of using manufactured shields increases with the decrease in the NPs size of the magnetite used as a reinforcement phase for a range of low operating voltages.

Increased antibacterial activity of silver nanoparticles synthesized from leaf extract of Isodon coetsa

Application of nanotechnology for the synthesis of silver nanoparticles using plant extract can be a promising alternative to traditional chemical methods. Products of biological origin have less side effects, thus are safe for human health besides being cost-effective and pollution-free. Keeping in view this, the current work was designed for the environment- friendly production of silver nanoparticles (AgNPs) utilising Isodon coetsa acetone leaf extract. The effect of some important variables including incubation time, pH, AgNO3 concentration, temperature and volume of plant extract were examined for the optimum production of AgNPs. Synthesized nanoparticles were further characterized using atomic force microscopy (AFM), X-ray diffraction spectroscopy (XRD), and UV-visible absorption spectroscopy. In addition, the antibacterial potential of nanoparticles was also determined by agar-well diffusion method. The optimal conditions for synthesis of AgNPs achieved after 24 h of incubation at pH 9.0, 2mM AgNO3, 60°C temperature, and using 10% I. coetsa leaf extract. X-ray diffraction spectroscopy revealed that the size of the strongest peak for AgNPs was 9.5 nm, while atomic force microscopy confirmed their spherical shape with smooth surface without any pinholes or cracks. AgNPs showed excellent antibacterial action against Gram-positive and Gram-negative bacteria. The current study has contributed to the development of a simple and fast bioprocess for the synthesis of AgNPs of the appropriate size and form which also have increased antibacterial activity in comparison to crude extract. Therefore, the process of biogenically synthesised AgNPs from plants is a straightforward, commercially feasible, and environmentally benign approach that can be used in disease control while utilizing their important role as therapeutic agent for treating various ailments caused by pathogenic bacteria.

Nanoscopic hygrometry: Exploiting porous nature zinc-doped tin oxide nanoparticles for enhanced humidity sensing at ambient temperature

This study focuses on zinc-doped tin oxide nanoparticles (Zn-SnO2 NPs) as promising humidity sensors. Through a chemical coprecipitation method, we synthesized Zn-SnO2 NPs and explored the influence of calcination temperature on their properties. X-ray diffraction confirmed the tetragonal rutile structure, and morphological analysis revealed a cauliflower-like morphology with enhanced porosity after calcination. UV-Visible absorption spectroscopy and photoluminescence measurements demonstrated a blue shift in the absorption peak and significant emission peaks related to oxygen vacancies, indicating improved humidity sensing potential as increasing the calcination temperature. The controlled calcination process led to successful outcomes, precisely tuning the NPs structure and optical behavior for enhanced humidity sensing capabilities. Conductivity studies have highlighted the semiconducting behavior of the NPs and observed that an increase in calcination temperature reduces their conductivity. Notably, humidity sensing experiments revealed a remarkable response of 93% and an exceptional response time of 30 seconds for the calcined NPs, surpassing the uncalcined sample. The sensing mechanism involving physisorption, chemisorption, and capillary condensation of water molecules on the NPs surface was validated. Moreover, the stability test over two month demonstrated consistent and highly stable humidity sensing response, reaffirming the NPs potential as effective and reliable humidity sensors.

A review: Comprehensive investigation on bandgap engineering under high pressure utilizing microscopic UV–Vis absorption spectroscopy

Bandgap engineering plays a vital role in material development and device optimization due to its significant impact on the photovoltaic and photoelectricity properties of materials. Nevertheless, it is still a great challenge to accurately control the bandgap of semiconductors to achieve the targeted properties of materials. Recently, pressure-induced bandgap regulation has emerged as a novel and effective tool to regulate bandgap, reveal the intrinsic band nature, and construct the in-depth structure–property relationships therein. In this review, the unique techniques of microscopic in situ steady-state UV–Vis absorption spectroscopy and high-pressure diamond anvil cell are introduced. This technique provides a powerful method to monitor the bandgap behaviors at high pressure. Then, the pressure-triggered bandgap responses are outlined based on several typical semiconductors, including metal halide perovskites, inorganic quantum dots, piezochromic molecular compounds, and two-dimensional semiconductor materials. The summarized structural effects on bandgap evolution and the general principles for bandgap engineering under high pressure are expected to provide guidance for further material design under ambient conditions. Microscopic absorption spectroscopy detection under high pressure is proven to be an ideal platform for developing functional materials and high-performance devices.

Synthesis and Characterization of Copper Nanoparticles Using Plant Extract of Mentha piperita Leaves, Anethum graveolens L., and Calotropis procera

Background: Synthesis of copper nanoparticles needs to be carried out with the use of environmentally safer alternatives. Plant-mediated nano-fabrication is a new area of nanotechnology that is favoured over traditional methods due to its effectiveness with respect to safety, affordability, environmental friendliness, and biocompatibility. Synthesis of copper nanoparticles using natural sources is the demand of this era. Methods: In the present study, the synthesis of copper nanoparticles (CuNPs) was carried out us-ing three different plant extracts, i.e., Mentha piperita, Anethum graveolens L., and Calotropis procera. This synthesis was carried out in different conditions and the visual colour change in the solution confirmed the presence of copper nanoparticles. The nanoparticles were also character-ized with UV-vis absorption spectroscopy and scanning electron microscope (SEM). Conclusion: In comparison to the synthetic route, the current work represents a cost-effective and sustainable way for the synthesis of nanoparticles.

Molecularly imprinted orthophenylenediamine with Ti3C2TxMXene‐based biosensor for sensitive detection of bilirubin

AbstractIn this study, bilirubin (BR) is detected by using a novel molecularly imprinted electrochemical sensor based on a Ti3C2TxMXene‐modified ITO electrode. First, Ti3C2TxMXene is synthesized by chemical etching and deposited at the ITO electrode surface by drop casting. After that, ortho‐phenylenediamine (o‐PD) as monomer is electropolymerized in the presence of a sodium acetate buffer solution containing the BR template to prepare BR‐imprinted electrode. Field emission scanning electron microscopy (FESEM), x‐ray diffraction and UV–visible absorption spectroscopy confirms the MXene synthesis. The molecular imprinted polymer (MIP) formation at the electrode is confirmed by electrochemical methods such as differential pulse voltammetry, electrochemical impedance spectroscopy, and cyclic voltammetry, and FESEM. The linearity range, limit of detection and the limit of quantification are calculated as 0.1 mg/dL to 20 mg/dL, 0.002 mg/dL, and 6.6 mg/dL respectively. Stability and reproducibility are also reported for the prepared MIP sensor.

Automatic Prediction of Peak Optical Absorption Wavelengths in Molecules Using Convolutional Neural Networks.

Molecular design depends heavily on optical properties for applications such as solar cells and polymer-based batteries. Accurate prediction of these properties is essential, and multiple predictive methods exist, from ab initio to data-driven techniques. Although theoretical methods, such as time-dependent density functional theory (TD-DFT) calculations, have well-established physical relevance and are among the most popular methods in computational physics and chemistry, they exhibit errors that are inherent in their approximate nature. These high-throughput electronic structure calculations also incur a substantial computational cost. With the emergence of big-data initiatives, cost-effective, data-driven methods have gained traction, although their usability is highly contingent on the degree of data quality and sparsity. In this study, we present a workflow that employs deep residual convolutional neural networks (DR-CNN) and gradient boosting feature selection to predict peak optical absorption wavelengths (λmax) exclusively from SMILES representations of dye molecules and solvents; one would normally measure λmax using UV-vis absorption spectroscopy. We use a multifidelity modeling approach, integrating 34,893 DFT calculations and 26,395 experimentally derived λmax data, to deliver more accurate predictions via a Bayesian-optimized gradient boosting machine. Our approach is benchmarked against the state of the art that is reported in the scientific literature; results demonstrate that learnt representations via a DR-CNN workflow that is integrated with other machine learning methods can accelerate the design of molecules for specific optical characteristics.

Correlating the Photovoltaic Performance and Stability of the All-Small-Molecule Organic Solar Cells to Their Intermixed Phases Determined by Concentration-Dependent Ultraviolet-Visible Absorption Spectroscopy.

In addition to the donor-acceptor nano phases, the intermixed phase within the organic blends is crucial for the photovoltaic performance and stability of the bulk-heterojunction organic solar cells (OSCs). Here, the intermixed phase of a representative M-PhS:BTP-eC9 all-small-molecule organic solar cell was investigated by a concentration-dependent ultraviolet-visible (UV-vis) absorption spectroscopy method, where a shift of the absorption maximum wavelength was measured for the acceptor component with the increase of the acceptor concentration. The blend ratios of the acceptor to the donor in the intermixed phase, corresponding to the critical concentration for the formation of the acceptor nanophase (CAP), were determined to be 0.35, 0.20, and 0.15 for the as-cast, thermal annealing (TA), and the combined TA and solvent vapor annealing films. These results indicated that M-PhS and BTP-eC9 are kinetically well intermixed during spin coating, whereas TA and the following solvent annealing promote the crystallization of BTP-eC9 molecules out of the intermixed phase. The photovoltaic performance of the M-PhS:BTP-eC9 cells with different blend ratios was investigated. The formation of the BTP-eC9 nano phase in the blend film leads to stable VOC and fast increased JSC, which can be understood by the reduction of bimolecular charge recombination and the formation of electron transporting pathways within the photoactive layer. Similarly, the critical concentration for the formation of the donor phase was estimated to be 0.15 by measuring the stabilized VOC and increased JSC values of the cells with different donor blending ratios. More importantly, after a fast "burn-in" thermal degradation, the M-PhS:BTP-eC9 cell showed excellent thermal stability aging at 85 °C for over 1128 h, which is in good accordance with the unchanged intermixed phases measured by the UV-vis spectra of the annealed films. The current work demonstrates the feasibility of the spectroscopy method to investigate the intermixed phases for organic bulk-heterojunction solar cells and proves that all-small-molecule solar cells can be intrinsically very stable.

Multi-spectroscopic and in silico investigation of gambogic acid–calf thymus DNA interactions

Gambogic acid (GA), a xanthanoid compound, is derived from Garcinia Hanbury gamboge resin. Studying GA's DNA binding and targeting processes is crucial to understanding its tumor-targeting potentiality. This study used spectroscopic and in silico methods to investigate the GA–calf thymus DNA-binding interaction. The results of the UV–visible absorbance spectroscopy revealed that GA binds to DNA and forms a complex. Investigation of fluorescence quenching using ethidium bromide-DNA revealed that GA displaced ethidium bromide, and the type of quenching was static in nature, as determined by Stern–Volmer plot data. Thermodynamic analysis of the DNA–GA complex revealed a spontaneous, favorable interaction involving hydrogen bonding and hydrophobic interactions. Quenching experiments with potassium iodide, Acridine orange, and NaCl verified GA's groove-binding nature and the presence of weak electrostatic interactions. The thermal melting temperature of DNA in its native and bound states with GA did not differ significantly (69.27° C to 71.25° C), validating the binding of GA to the groove region. Furthermore, the groove-binding nature of GA was confirmed by studying its interaction with ssDNA and DNA viscosity. The methods of DSC, FT-IR, and CD spectroscopy have not revealed any structural aberrations in DNA bound with GA. Molecular docking and modeling studies revealed that GA has a groove-binding nature with DNA, which is consistent with prior experimental results. Finally, the findings shed information by which GA attaches to DNA and provide insights into its recognized anticancer effects via topoisomerase inhibition causing DNA cleavage, inhibition of cell proliferation and apoptosis. Communicated by Ramaswamy H. Sarma

Synergistic effects of Core@Shell (CZTS@CZTSe) on photovoltaic & photocathode applications

Nanotechnology has undergone significant advancements attributable to the synthesis of nanoparticles (NPs), reflecting the collaborative endeavours of numerous researchers. This investigation contributes to the field by fabricating core–shell (Csh) NPs composed of CZTS (Cu2ZnSnS4)-CZTSe(Cu2ZnSn(SSe)4), exhibiting potential applications as photocatalysts for water treatment and photocathodes for solar cells. Utilizing the innovative “Hot-Injection” method in NP synthesis represents a noteworthy breakthrough, facilitating a reduction in reaction time and enabling precise control over morphology. Characterization employing diverse techniques has unveiled noteworthy structural and electrochemical properties. This includes the identification of a Kesterite phase with varying S and Se ratios, as well as binary/ternary phases influencing purity. UV–vis absorbance spectroscopy has provided insights into electronic properties, while electrochemical impedance spectroscopy has indicated the low charge transfer resistance (Rct) of the CZTS80Se20 core–shell structure, positioning it as a prime candidate for application procedures. Photocatalytic efficiency assessment involved subjecting the NPs to Methylene blue dye under visible light, resulting in a maximum efficiency of 99.9% within a certain range of catalyst concentrations. This study also demonstrated the NP’s suitability as absorber layers of optimal thickness in solar cells, deposited through the Electrophoretic Deposition (EPD) technique. Linear and symmetric I-V response results indicate the ohmic nature of the contacts. This research represents a significant stride forward, unveiling promising prospects for the utilisation of core–shell CZTS-CZTSe NPs across.

Multifaceted Applications of DNA-Capped Silver Nanoparticles in Photonics, Photocatalysis, Antibacterial Activity, Cytotoxicity, and Bioimaging.

Deoxyribonucleic acid (DNA) capped silver nanoparticles are exceptional nanomaterials, featuring precise size and shape control enabled by DNA as a capping agent. DNA stabilizes these nanoparticles' role leading to uniform structures for diverse applications. These nanoparticles are excellent in photonics and medical applications, enhancing fluorescence and medical imaging. In this study, we explore the multifaceted applications of DNA-capped silver nanoparticles, delving into their optical, photocatalytic, antibacterial, cytotoxic, and bioimaging properties. Employing UV-visible absorption spectroscopy and scanning electron microscopy, we provide an analysis of confirmation of silver nanoparticles. The investigation demonstrates substantial photocatalytic efficacy, photodegradation of methylene blue is higher than rhodamine 6G. The presence of silver nanoparticles enhances the fluorescence of rhodamine 6G doped sol-gel glasses. Furthermore, our findings illustrate significant antibacterial effects, encompassing both Gram-positive and Gram-negative bacteria, with DNA-capped silver nanoparticles exhibiting antibacterial activity. Cytotoxicity assessments on HeLa cells reveal concentration-dependent effects, with an LC50 value of 47 µL. Additionally, thein vitro experiments with HeLa cells suggest the promising utility of DNA-capped silver nanoparticles for bioimaging applications. This comprehensive analysis highlights the multifunctionality and potential of DNA-capped silver nanoparticles, offering promising avenues for further exploration and innovation within various scientific domains, particularly in the realm of nanomaterial research.

Multi-functional nanoscale ZrO2 catalysts for sustainable water treatment

This study aimed to synthesize highly reactive ZrO2 nanoparticles using a straightforward sol-gel method for addressing water contamination from hazardous metal ions and organic dyes. Structural and photocatalytic properties were assessed using X-ray diffraction (XRD), Fourier transmission Infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and UV–visible absorption spectroscopy. XRD analysis confirmed the tetragonal crystal structure of ZrO2. Photodegradation experiments using Eriochrome Black T (EBT) as a model dye revealed nearly 99% degradation under natural sunlight. Investigations into catalyst loading, dye concentration, pH, and irradiation source were conducted. Preliminary tests demonstrated the adsorbent's efficacy in removing Ca2+ ions. Further process optimizations could significantly enhance the potential of this innovative adsorbent for extracting metal ions from complex effluents.

Luminescence properties of (Gd, M)2O2S: Tb3+, Dy3+ (M = Lu, Y, Zn, Ti) phosphors

(Gd, M)2O2S: 3.5 %Tb3+, 0.75 %Dy3+ (M = Lu, Y, Zn, Ti) phosphors were prepared using a molten salt method. The samples were characterized using XRD, SEM, UV–visible absorption spectroscopy, photoluminescence and cathodoluminescence. The XRD results showed that the phosphors introduced by different cations were still hexagonal crystal system although the unit cell shrinks. SEM showed particle sizes between 150∼1000 nm. The doping of Dy3+ can effectively improve the luminescence of Tb3+. The photo- and cathodo-luminescence spectra of (Gd, M)2O2S: 3.5 %Tb3+, 0.75 %Dy3+ indicated the luminescence intensity of Gd2O2S: 3.5 %Tb3+, 0.75 %Dy3+ can be effectively improved that when adding M = Lu, Y, Zn. The same energy transfer mechanism was followed. (Gd, Ti)2O2S: 3.5 %Tb3+, 0.75 %Dy3+ possessed favorable thermal stability. When the temperature rose to 425 K, the luminescence intensity was 74.6 % of that at 300 K. The charge-transfer process of Tb3++Ti4+↔ Tb4++Ti3+ provides new ideas for obtaining high thermal stability sulfur oxide phosphors.

Evidence of direct interaction between cisplatin and the caspase-cleaved prostate apoptosis response-4 tumor suppressor.

Prostate apoptosis response-4 (Par-4) tumor suppressor protein has gained attention as a potential therapeutic target owing to its unique ability to selectively induce apoptosis in cancer cells, sensitize them to chemotherapy and radiotherapy, and mitigate drug resistance. It has recently been reported that Par-4 interacts synergistically with cisplatin, a widely used anticancer drug. However, the mechanistic details underlying this relationship remain elusive. In this investigation, we employed an array of biophysical techniques, including circular dichroism spectroscopy, dynamic light scattering, and UV-vis absorption spectroscopy, to characterize the interaction between the active caspase-cleaved Par-4 (cl-Par-4) fragment and cisplatin. Additionally, elemental analysis was conducted to quantitatively assess the binding of cisplatin to the protein, utilizing inductively coupled plasma-optical emission spectroscopy and atomic absorption spectroscopy. Our findings provide evidence of direct interaction between cl-Par-4 and cisplatin, and reveal a binding stoichiometry of 1:1. This result provides insights that could be useful in enhancing the efficacy of cisplatin-based and tumor suppressor-based cancer therapies.