Solid state engineering of Bi2S3/rGO nanostrips: an excellent electrode material for energy storage applications.

The study presents a novel, one-pot, and scalable solid-state reaction scheme to prepare bismuth sulphide (Bi2S3)-reduced graphene oxide (rGO) nanocomposites using bismuth oxide (Bi2O3), thiourea (TU), and graphene oxide (GO) as starting materials for energy storage applications. The impact of GO loading concentration on the electrochemical performance of the nanocomposites was investigated. The reaction follows a diffusion substitution pathway, gradually transforming Bi2O3 powder into Bi2S3 nanostrips, concurrently converting GO into rGO. Enhanced specific capacitances were observed across all nanocomposite samples, with the Bi2S3@0.2rGO exhibiting the highest specific capacitance of 705 F g-1 at a current density of 1 A g-1 and maintaining a capacitance retention of 82% after 1000 cycles. The superior specific capacitance is attributed to the excellent homogeneity and synergistic relation between rGO and Bi2S3 nanostrips. This methodology holds promise for extending the synthesis of other chalcogenides-rGO nanocomposites.

Topological phases in nanoparticle monolayers: can crystalline, hexatic, and isotropic-fluid phases coexist in the same monolayer?

Topological phases are stable configurations of matter in 2-dimensions (2D) formed via spontaneous symmetry breaking. These play a crucial role in determining the system properties. Though a number of fundamental studies on topological phase transitions and topological defect dynamics have been conducted with model colloidal systems (typically microns in size), the same is lacking on nanoparticle monolayers (NPMLs, typically made of ligand-coated sub-ten nanometer particles). Here, we show that in an evaporation-driven self-assembly process, the three topological phases, namely crystalline, hexatic, and isotropic-fluid phases, can coexist within the same NPML. We associate this coexistence with the local variation in particle size, which can be described by a unique frequency parameter (p25), quantifying the fraction of NPs that has size deviation greater than or equal to 25% of the mean size (where the deviation,ζ is defined as ζ = ((|Size-mean|)/mean)). The p25-values for the three phases are distinctly different: crystalline arrangement occurs when p25 < ∼0.02, while a hexatic phase exists for 0.02 ≤ p25 ≤ 0.1. For p25 ≥ 0.1, the isotropic-fluid phase occurs. Following KTHNY-theory, we further numerically extrapolate the occurrence of each phase to the accumulated excess planar strain in the NPML due to the presence of various topological defects in the structures.

Correction: Surface functionalization of inorganic nanoparticles with ligands: a necessary step for their utility.

Correction for 'Surface functionalization of inorganic nanoparticles with ligands: a necessary step for their utility' by Kaustav Bhattacharjee et al., Chem. Soc. Rev., 2023, 52, 2573-2595, https://doi.org/10.1039/D1CS00876E.

Surface functionalization of inorganic nanoparticles with ligands: a necessary step for their utility.

The importance of organic ligands in protecting inorganic nanoparticles and thus imparting the needed stabilization as colloidal dispersions was realised many years ago. Currently, the rational preparation of such nanoparticles with designed organic molecules/ligands resulting in the formation of functional nanoparticles (FNPs) that are tuned for a specific application is an area of immense research interest. The preparation of such FNPs for a desired application requires a clear understanding of the interactions at the nanoparticle (NP)-ligand and ligand-solvent interfaces, and demands a deep appreciation of the surface science and coordination chemistry. In this tutorial review, we briefly explore the evolution of surface-ligand chemistry and inform the readers that, apart from protecting the surface, ligands can modulate the physico-chemical properties of the underlying inorganic NPs as well. This review further presents the design principles for the rational preparation of such FNPs, where one or more ligand shells can be added to the nanoparticle surface, thereby improving the adaptability and amenability of the NP exterior towards the environment in which they are present, as required for a specific application.

PRIVEE: A Visual Analytic Workflow for Proactive Privacy Risk Inspection of Open Data.

Open data sets that contain personal information are susceptible to adversarial attacks even when anonymized. By performing low-cost joins on multiple datasets with shared attributes, malicious users of open data portals might get access to information that violates individuals' privacy. However, open data sets are primarily published using a release-and-forget model, whereby data owners and custodians have little to no cognizance of these privacy risks. We address this critical gap by developing a visual analytic solution that enables data defenders to gain awareness about the disclosure risks in local, joinable data neighborhoods. The solution is derived through a design study with data privacy researchers, where we initially play the role of a red team and engage in an ethical data hacking exercise based on privacy attack scenarios. We use this problem and domain characterization to develop a set of visual analytic interventions as a defense mechanism and realize them in PRIVEE, a visual risk inspection workflow that acts as a proactive monitor for data defenders. PRIVEE uses a combination of risk scores and associated interactive visualizations to let data defenders explore vulnerable joins and interpret risks at multiple levels of data granularity. We demonstrate how PRIVEE can help emulate the attack strategies and diagnose disclosure risks through two case studies with data privacy experts.

pH responsive cylindrical MSN for oral delivery of insulin-design, fabrication and evaluation.

OBJECTIVE: The objective of the present study was to develop novel PMV [poly (methacrylic acid-co-vinyl triethoxylsilane)]-coated mesoporous silica nanoparticles (MSN) with improved hypoglycemic effect for oral insulin (INS) delivery. METHODS: MSN was synthesized under acidic condition using Pluronic® P 123 and Tetra ethoxy orthosilane. Surfactant was removed by calcination. Calcined MSN was coated with pH sensitive polymer PMV. Cytotoxicity of this coated MSN was evaluated by MTT assay using CHO-K1 cell line. Different MSN samples were characterized with BET surface area analyzer, FESEM, TEM, FT-IR, XRD, TG-DTA. In vivo study was performed using male rats. Pharmacokinetic study was conducted using HPLC. RESULTS AND DISCUSSION: Highest surface area (304.3921 m2/g) was observed in case of calcined sample. Adsorption pore width of final coated sample was highest (64.7844 nm) compared with others. No noticeable cytotoxicity was observed for this coated support. The entrapment efficiency of insulin was found to be 39.39%. In vitro studies were done at different pH using Franz-diffusion cell. Results showed significant release at pH 7.4. Cumulative drug release over a period of 6 h was more than 48% at this systemic pH. Effect of this MSN-PMV-INS on blood glucose level was retained for 16 h. This novel formulation has shown 73.10% relative bioavailability of insulin. CONCLUSION: A novel-coated mesoporous silica support was successfully developed for delivery of insulin through oral route.

High critical field NbC superconductor on carbon spheres.

Niobium carbide (NbC) nanoparticles embedded on the surface of carbon spheres (CS) were synthesized at 1350 °C by the carbothermal reduction of niobium oxide precursor in flowing argon (Nbc@CS). The morphology, crystal structure, and magnetic properties of the hybrid nanocomposite were investigated by means of electron microscopy, X-ray diffraction and a superconducting quantum interference device. It was found that the NbC@CS nanocomposites exhibit type-II superconductivity with a critical temperature (Tc) of 8-12 K, typical for stoichiometric NbC. The superconducting hysteresis loop reveals several interesting traits, including strong vortex pinning, the presence of asymmetry and a high penetration field. Moreover, the sample shows much improved irreversible (Hirr), lower (Hc1) and upper (Hc2) critical fields. The coherence length (ξ), penetration depth (λ), and Ginzburg-Landau (κ) parameters for the sample were estimated to be 9.78 nm, 33 nm and 3.39, respectively.

In Vitro Evaluation of pH Responsive Doxazosin Loaded Mesoporous Silica Nanoparticles: A Smart Approach in Drug Delivery.

OBJECTIVE: To develop a pH responsive drug delivery system (DDS) for controlled release of therapeutic cargo, Doxazosin Mesylate (DZM) which was loaded into carrier material mesoporous silica nanoparticle (MSN) and subsequently coated with Eudragit S-100(ES-100) to release the drug at pH 7.4. MATERIAL AND METHODS: We have synthesized cylindrical MSN under acidic condition using non-ionic surfactant (Pluronic(®) P 123) and Tetraethoxysilane (TEOS). After post synthesis treatment (PST) surfactant was removed by calcination. To obtain pH sensitive release calcined MSN was coated with ES-100 (MSN-DZMES100). The Brauner-Emmett-Teller (BET) surface area, adsorption isotherm, t-plot, pore volume of MSN were done in surface area analyzer to characterize different MSN samples (as synthesized, calcined, and coated). RESULT AND DISCUSSION: Highest surafce area (427.114 m(2)/g) was observed in case of calcined sample when compared to as synthesized (3.1198m(2)/g) and coated MSN (8.8480m(2)/g). Adsorption pore width of final coated sample was 12.58 nm whereas as synthesized and calcined samples possessed pore width 36.82 nm and 7.32 nm respectively. All uncoated and coated MSN samples were further characterized with FESEM, TEM, FTIR. No significant interaction between drug and MSN was found from FTIR studies. The drug loading into coated mesoporous support was found to be 43.7%. In vitro studies were done at different pH using Franz-diffusion cell. Results showed significant release at pH 7.4 from MSNDZM- ES100. Cumulative drug release over a period of 10 hr was 81% at this systemic pH. CONCLUSION: ES-100 coated mesoporous silica nanoparticle is a smart carrier for pH responsive release of guest molecule.

Influence of spherical assembly of copper ferrite nanoparticles on magnetic properties: orientation of magnetic easy axis.

The magnetic properties of copper ferrite (CuFe2O4) nanoparticles prepared via sol-gel auto combustion and facile solvothermal method are studied focusing on the effect of nanoparticle arrangement. Randomly oriented CuFe2O4 nanoparticles (NP) are obtained from the sol-gel auto combustion method, while the solvothermal method allows us to prepare iso-oriented uniform spherical ensembles of CuFe2O4 nanoparticles (NS). X-ray diffractometry (XRD), atomic absorption spectroscopy (AAS), infra-red (IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), (57)Fe Mössbauer spectroscopy and vibrating sample magnetometer (VSM) are used to investigate the composition, microstructure and magnetic properties of as-prepared ferrite nanoparticles. The field-dependent magnetization measurement for the NS sample at low temperature exhibits a step-like rectangular hysteresis loop (M(R)/M(S) ~ 1), suggesting cubic anisotropy in the system, whereas for the NP sample, typical features of uniaxial anisotropy (M(R)/M(S) ~ 0.5) are observed. The coercive field (HC) for the NS sample shows anomalous temperature dependence, which is correlated with the variation of effective anisotropy (K(E)) of the system. A high-temperature enhancement of H(C) and K(E) for the NS sample coincides with a strong spin-orbit coupling in the sample as evidenced by significant modification of Cu/Fe-O bond distances. The spherical arrangement of nanocrystals at mesoscopic scale provokes a high degree of alignment of the magnetic easy axis along the applied field leading to a step-like rectangular hysteresis loop. A detailed study on the temperature dependence of magnetic anisotropy of the system is carried out, emphasizing the influence of the formation of spherical iso-oriented assemblies.

A spectroscopic investigation on the interaction of a magnetic ferrofluid with a model plasma protein: effect on the conformation and activity of the protein.

The understanding of the interaction of nanomaterials with relevant biological targets e.g., proteins is of paramount importance in biological and pharmaceutical fields of research. In a biological fluid, proteins can associate with nanomaterials which can subsequently exert a significant impact on the conformation and functionality of the protein. Here we report the binding interaction of a model plasma protein Bovine Serum Albumin (BSA) with a magnetic nanoparticle of mixed spinel origin (Ni(0.5)Zn(0.5)Fe(2)O(4), abbreviated as NZFO from now and onwards). The thermodynamic parameters (ΔH, ΔS and ΔG) for the protein-nanoparticle binding interaction have been evaluated from the van't Hoff equation to unveil that the binding interaction is enthalpically as well as entropically driven (ΔH < 0 and ΔS > 0), with an overall favorable Gibbs free energy change (ΔG < 0). Also the thermodynamic parameters delineate the predominant role of electrostatic interaction in the BSA-NZFO binding process. The results of temperature dependent fluorescence quenching and time-resolved fluorescence decay measurements indicate a static quenching mechanism in the present case. Steady-state absorption, synchronous fluorescence, three-dimensional (3D) fluorescence and circular dichroism (CD) spectroscopic techniques have been employed to unveil the conformational changes in BSA induced by the binding of NZFO. Disruption of the native conformation of the protein upon binding with NZFO is reflected through a reduced functionality (in terms of esterase activity) of the protein-NZFO conjugate system in comparison to the native protein. Based on the experimental findings the probable binding location of NZFO is argued to be the hydrophilic domain IB. This seems physically realizable since domain I of BSA is characterized by a net negative charge and hence can serve as a favorable binding site for NZFO carrying a positive surface charge. The key role of electrostatic forces in the BSA-NZFO interaction process is further substantiated from chemical denaturation study and measurement of the effect of ionic strength on the interaction process.