Search Results (324)

Background/Objectives: 16S ribosomal RNA sequencing has, for several years, been the main means of identifying bacterial and archaeal species. Low-throughput Sanger sequencing is often used for the detection and identification of microbial species, but this technique has several limitations. The use of high-throughput sequencers may be a good alternative to improve patient identification, especially for polyclonal infections and management. Kraken 2 and KrakenUniq are free, high-throughput tools providing a very rapid and accurate classification for metagenomic analyses. However, Kraken 2 can present false-positive results relative to KrakenUniq, which can be limiting in hospital settings requiring high levels of accuracy. The aim of this study was to establish an alternative next-generation sequencing technique to replace Sanger sequencing and to confirm that KrakenUniq is an excellent analysis tool that does not present false results relative to Kraken 2. Methods: DNA was extracted from reference bacterial samples for Laboratory Quality Controls (QCMDs) and the V2-V3 and V3-V4 regions of the 16S ribosomal gene were amplified. Amplified products were sequenced with the Illumina 16S Metagenomic Sequencing protocol with minor modifications to adapt and sequence an Illumina 16S library with a small 500-cycle nano-flow cell. The raw files (Fastq) were analyzed on a commercial Smartgene platform for comparison with Kraken 2 and KrakenUniq results. KrakenUniq was used with a standard bacterial database and with the 16S-specific Silva138, RDP11.5, and Greengenes 13.5 databases. Results: Seven of the eight (87.5%) QCMDs were correctly sequenced and identified by Sanger sequencing. The remaining QCMD, QCMD6, could not be identified through Sanger sequencing. All QCMDs were correctly sequenced and identified by MiSeq with the commercial Smartgene analysis platform. QCMD6 contained two bacteria, Acinetobacter and Klebsiella. KrakenUniq identification results were identical to those of Smartgene, whereas Kraken 2 yielded 25% false-positive results. Conclusions: If Sanger identification fails, MiSeq with a small nano-flow cell is a very good alternative for the identification of bacterial species. KrakenUniq is a free, fast, and easy-to-use tool for identifying and classifying bacterial infections. Full article

Under elevated loading conditions, the aggregation of fillers emerges as a pivotal factor driving the degradation of separation performance in mixed matrix membranes. The two-dimensional (2D) modification of fillers, aimed at enhancing interfacial contact with polymers, has been recognized as an effective strategy to improve interphase compatibility and increase filler loading capacity. However, it is worth noting that the BET surface area of 2D fillers is typically relatively low. In this study, a two-step approach was developed. First, a “diffusion-mediated” process was combined with a solvent optimization strategy based on first-principles (DFT) calculations, achieving a 20-fold suppression in ZIF-67 nucleation-crystallization rate. This enabled the successful synthesis of a 2D amorphous nanoflower structure. Subsequently, the processing parameters were fine-tuned to enhance the specific surface area of ZIF-67 to 403 m²/g while preserving its 2D structural integrity. Ultimately, the as-prepared 2D ZIF-67 was incorporated into a hydrogenated styrene-butadiene block copolymer (SEBS) matrix to fabricate a mixed matrix membrane. Remarkably, at a filler loading of 20 wt%, the CH₄ permeability coefficient increased significantly from 11.7 barrer to 35.3 barrer, while the CH₄/N₂ selectivity was maintained at 3.21, indicating minimal interfacial defects and demonstrating the feasibility and effectiveness of the proposed methodology. Full article

Aiming to address the key challenges of poor enzyme stability, difficult recovery, and difficult synergistic optimization of catalytic efficiency in high-value conversion of biomass, this study utilizes mineralization self-assembly technology to combine laccase with Fe₃O₄@SiO₂-PMIDA-Cu²⁺ composite, constructing magnetic laccase nanoflower (MLac-NFs) materials with a porous structure and superparamagnetism. This synthetic material can efficiently catalyze the selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). The characterization results indicated that MLac-NFs exhibit optimal catalytic activity (63.4 U mg⁻¹) under conditions of pH 6.0 and 40 °C, with significantly enhanced storage stability (retaining 94.26% of activity after 30 days of storage at 4 °C). Apparent kinetic analysis reveals that the substrate affinity and maximum reaction rate of MLac-NFs were increased by 38.3% and 439.6%, respectively. In the laccase–mediator system (LMS), MLac-NFs mediated by 30 mM TEMPO could achieve complete conversion of HMF to FDCA within 24 h. Moreover, due to the introduction of magnetic nanoparticles, the MLac-NFs could be recovered and reused via an external magnetic field, maintaining 53.26% of the initial FDCA yield after six cycles. Full article

Human cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) braziliensis is a complex parasitic disease marked by dynamic host–parasite interactions and immunomodulation. Extracellular vesicles (EV) derived from immune cells have emerged as key mediators of intercellular communication and potential biomarkers in infectious diseases. In this study, we combined a modified lymphocyte proliferation assay with nano-flow cytometry to quantify and phenotype EV released by CD4⁺, CD8⁺, and CD14⁺ cells in PBMC cultures from CL patients at different clinical stages: before treatment (PBT), during treatment (PDT), and post-treatment (PET) with antimonial. Healthy individuals (HI) were included as physiological controls. Upon stimulation with L. (V.) braziliensis antigens, we observed a distinct modulation of EV subsets. In the PBT group, CD4⁺ and CD14⁺ EV were significantly reduced, while CD8⁺ EV remained elevated. During PDT and PET, EV concentrations were restored across all subsets. These findings suggest that L. (V.) braziliensis selectively modulates the release of immune cell–derived EV, possibly as an immune evasion mechanism. The restoration of EV release following antimonial therapy highlights their potential as sensitive biomarkers for disease activity and treatment monitoring. This study offers novel insights into the immunoregulatory roles of EV in CL and underscores their relevance in host–parasite interactions. Full article

The lateral flow immunoassay (LFIA) is a widely utilized, rapid diagnostic technique characterized by its short analysis duration, cost efficiency, visual result interpretation, portability and suitability for point-of-care applications. However, conventional LFIAs have limited sensitivity, a challenge that can be overcome by the introduction of gold nanoparticles, which provide enhanced sensitivity and selectivity (compared, for example, to latex beads or carbon nanoparticles) for the detection of target analytes, due to their optical properties, chemical stability and ease of functionalization. In this work, gold nanoparticle-based LFIAs are developed for the detection of aflatoxin B1, and the relative performance of different morphology particles is evaluated. LFIA using gold nano-labels allowed for aflatoxin B1 detection over a range of 0.01 ng/mL–100 ng/mL. Compared to spherical gold nanoparticles and gold nano-flowers, star-shaped gold nanoparticles show increased antibody binding efficiency of 86% due to their greater surface area. Gold nano-stars demonstrated the highest sensitivity, achieving a limit of detection of 0.01ng/mL, surpassing the performance of both spherical gold nanoparticles and gold nano-flowers. The use of star-shaped particles as nano-labels has demonstrated a five-fold improvement in sensitivity, underscoring the potential of integrating diverse nanostructures into LFIA for significantly improving analyte detection. Moreover, the robustness and feasibility of gold nano-stars employed as labels in LFIA was assessed in detecting aflatoxin B1 in a wheat matrix. Improved sensitivity with gold nano-stars holds promise for applications in food safety monitoring, public health diagnostics and rapid point-of-care diagnostics. This work opens the pathway for further development of LFIA utilizing novel nanostructures to achieve unparallel precision in diagnostics and sensing. Full article

Rapid screening of foodborne pathogens is critical for food safety, yet current detection techniques often suffer from low efficiency and complexity. In this study, we developed a sliding microfluidic colorimetric biosensor for the fast, sensitive, and multiplex detection of Salmonella. First, the target bacteria were specifically captured by antibody-functionalized magnetic nanoparticles in the microfluidic chip, forming magnetic bead–bacteria complexes. Then, through motor-assisted sliding of the chip, manganese dioxide (MnO₂) nanoflowers conjugated with secondary antibodies were introduced to bind the captured bacteria, generating a dual-antibody sandwich structure. Finally, a second sliding step brought the complexes into contact with a chromogenic substrate, where the MnO₂ nanoflowers catalyzed a colorimetric reaction, and the resulting signal was used to quantify the Salmonella concentration. Under optimized conditions, the biosensor achieved a detection limit of 10 CFU/mL within 20 min. In spiked pork samples, the average recovery rate of Salmonella ranged from 94.9% to 125.4%, with a coefficient of variation between 4.0% and 6.8%. By integrating mixing, separation, washing, catalysis, and detection into a single chip, this microfluidic biosensor offers a user-friendly, time-efficient, and highly sensitive platform, showing great potential for the on-site detection of foodborne pathogens. Full article

Cell-penetrating peptides offer a promising strategy for intracellular delivery; however, non-specific uptake and off-target cytotoxicity limit their clinical utility. To address these limitations, a cold atmospheric plasma-responsive delivery platform was developed in which the membrane activity of a peptide was transiently suppressed upon complexation with a DNA-based nanostructure. Upon localized plasma exposure, DNA masking was disrupted, restoring the biological functions of the peptides. Transmission electron microscopy revealed that the synthesized DNA nanoflower structures were approximately 150–250 nm in size. Structural and functional analyses confirmed that the system remained inert under physiological conditions and was rapidly activated by plasma treatment. Fluorescence recovery, cellular uptake assays, and cytotoxicity measurements demonstrated that the peptide activity could be precisely controlled in both monolayer and three-dimensional spheroid models. This externally activatable nanomaterial-based system enables the spatial and temporal regulation of peptide function without requiring biochemical triggers or permanent chemical modifications. This platform provides a modular strategy for the development of potential peptide therapeutics that require precise control of activation in complex biological environments. Full article

This review synthesized the current knowledge on the effect of TiO₂ photocatalysts on the degradation of microplastics (MPs) and nanoplastics (NPs) under visible light, highlighting the state-of-the-art techniques, main challenges, and proposed solutions for enhancing the performance of the photocatalysis technique. The synthesis of TiO₂-based photocatalysts and hybrid nanostructured TiO₂ materials, including those coupled with other semiconductor materials, is explored. Studies on TiO₂-based photocatalysts for the degradation of MPs and NPs under visible light remain limited. The degradation behavior is influenced by the composition of the TiO₂ composites and the nature of different types of MPs/NPs. Polystyrene (PS) MPs demonstrated complete degradation under visible light photocatalysis in the presence of α-Fe₂O₃ nanoflowers integrated into a TiO₂ film with a hierarchical structure. However, photocatalysis generally fails to achieve the full degradation of small plastic pollutants at the laboratory scale, and its overall effectiveness in breaking down MPs and NPs remains comparatively limited. Full article

The electrocatalytic decomposition of ammonia represents a promising route for sustainable hydrogen production, yet current systems rely heavily on noble metal catalysts with prohibitive costs and limited durability. A critical challenge lies in developing non-noble electrocatalysts that simultaneously achieve high active site exposure, optimized electronic configurations, and robust structural stability. Addressing these requirements, this study strategically engineered Cu-doped ZIF-8 architectures via in situ growth on nickel foam (NF) substrates through a facile room-temperature hydrothermal synthesis approach. Systematic optimization of the Cu/Zn molar ratio revealed that Cu_0.7Zn_0.3-ZIF/NF achieved optimal performance, exhibiting a distinctive nanoflower-like architecture that substantially increased accessible active sites. The hybrid catalyst demonstrated superior electrocatalytic performance with a current density of 124 mA cm⁻² at 1.6 V vs. RHE and a notably low Tafel slope of 30.94 mV dec⁻¹, outperforming both Zn-ZIF/NF (39.45 mV dec⁻¹) and Cu-ZIF/NF (31.39 mV dec⁻¹). Combined XPS and EDS analyses unveiled a synergistic electronic structure modulation between Zn and Cu, which facilitated charge transfer and enhanced catalytic efficiency. A gas chromatography product analysis identified H₂ and N₂ as the primary gaseous products, confirming the predominant occurrence of the ammonia oxidation reaction (AOR). This study not only presents a noble metal-free electrocatalyst with exceptional efficiency and durability for ammonia decomposition but also demonstrates the significant potential of MOF-derived materials in sustainable hydrogen production technologies. Full article

A three-dimensional Bi-enriched Bi₂O₃/Bi₂MoO₆ Z-scheme heterojunction photocatalyst was successfully synthesized via a facile one-step hydrothermal method for efficient phenol degradation under visible light. Structural and morphological characterizations (SEM, TEM, and XRD) confirmed the formation of a nanoflower-like architecture with a high specific surface area of 81.27 m²/g. Optical and electrochemical analyses revealed efficient charge separation and extended visible-light response. Under visible-light irradiation (λ > 420 nm), this heterojunction (Bi₂O₃:Bi₂MoO₆ = 3:7) demonstrated exceptional performance, degrading 97.06% of phenol (30 mg/L) within 60 min. XPS analysis confirmed the Z-scheme charge transfer mechanism: Photogenerated electrons in the conduction band of Bi₂O₃ (−0.59 eV) facilitated the generation of ·O₂⁻ radicals, while holes in the valence band of Bi₂MoO₆ (2.44 eV) predominantly produced ·OH radicals. This synergistic effect resulted in highly efficient mineralization and degradation of phenol. Full article

In the present investigation, an eco-friendly biocatalyst was developed using Pleurotus eryngii laccase (PeLac) through a copper (Cu)-based protein–inorganic hybrid system for the degradation of bisphenol A, a representative xenobiotic. After partial purification, the specific activity of crude PeLac was 92.6 U/mg of total protein. Immobilization of PeLac as Cu₃(PO₄)₂–Lac (Cu–PeLac) nanoflowers (NFs) at 4 °C resulted in a relative activity 333% higher than that of the free enzyme. The Cu–PeLac NFs exhibited greater pH and temperature stability and enhanced catalytic activity compared to free laccase. This enhanced activity was validated through improved electrochemical properties. After immobilization, Cu–PeLac NFs retained up to 8.7-fold higher residual activity after storage at 4 °C for 30 days. Free and immobilized laccase degraded bisphenol A by 41.6% and 99.8%, respectively, after 2 h of incubation at 30 °C. After ten cycles, Cu–PeLac NFs retained 91.2% degradation efficiency. In the presence of potent laccase inhibitors, Cu–PeLac NFs exhibited a 47.3-fold improvement in bisphenol A degradation compared to free PeLac. Additionally, the synthesized Cu–PeLac NFs demonstrated lower acute toxicity against Vibrio fischeri than Cu nanoparticles. This study presents the first report of PeLac immobilization through an eco-friendly protein–inorganic hybrid system, with promising potential for degrading bisphenol A in the presence of inhibitors to support sustainable development. Full article

Growing demand for chemically resistant, thermally stable, and anti-icing coatings has intensified interest in boron nitride (BN)-based materials and surface coatings. In this study, BN coatings were developed on mild steel (MS) via chemical vapour deposition (CVD) at 1200 °C for 15, 30, and 60 min, and their structural, surface, and water-repellent characteristics were evaluated. X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy confirmed the successful formation of BN, while water contact angle measurements indicated high hydrophobicity, demonstrating excellent barrier properties. Scanning electron microscopy (SEM) revealed morphological evolution from flower- and needle-like BN structures in the sample placed in the CVD furnace for 15 min to dense, coral-like, and tubular networks in the samples placed for 30 and 60 min. These findings highlight that BN coatings, particularly the one obtained after 30 min of deposition, have a high hydrophobic character following the Cassie–Baxter model and can be used for corrosion resistance and anti-icing on MS, making them ideal for industrial applications requiring long-lasting protection. Full article

In this study, Bi₂MoO₆ nanoflowers with different molybdenum sources were in situ grown on the surface of g-C₃N₄ nanosheets (OCN) by a simple one-step solvothermal method. The effects of doping and different molybdenum sources on the photocatalytic degradation and bactericidal activity of Bi₂MoO₆/OCN were discussed. Among them, the solvothermal preparation of P-Bi₂MoO₆/OCN using phosphomolybdic acid as molybdenum source can make up for the shortcomings caused by the destruction of OCN structure by generating more lattice defects to promote charge separation and constructing Lewis acid/base sites to effectively improve the photocatalytic performance. In addition, by adding phosphoric acid to increase the P-doped content, more exposed alkaline active sites are induced on the surface of P-Bi₂MoO₆/OCN, as well as larger specific surface area and charge transfer efficiency, which further improve the photocatalytic performance. Finally, the optimized 16P-Bi₂MoO₆/OCN showed a degradation rate of 99.7% for 20 mg/L rhodamine B (RhB) within 80 min under visible light, and the antibacterial rates against E. coli, S. aureus and P. aeruginosa within 300 min were 99.58%, 98.20% and 97.48%, respectively. This study provides a reference for optimizing the synthesis of environmentally friendly, solar-responsive, photocatalytic sterilization materials from the perspective of preparation, raw materials and structure. Full article

A nanoflower-like nickel-molybdenum alloy was synthesized by hydrothermal in situ growth of NiMoO₄ nanorod arrays on nickel foam (NF) followed by gas-phase re-reduction at 600 °C. The resulting structure has a uniform porosity and high specific surface area, which improves the availability of active sites and facilitates efficient electron and mass transport. SEM and XPS analyses confirm that the formed NiMoO₄ nanorods are uniformly distributed, which leads to significant optimization of their electronic structure. The electrochemical measurements revealed that the sample exhibited excellent hydrogen evolution reaction (HER) performance, with an overpotential as low as 127 mV at 100 mA cm⁻² and a Tafel slope of 124 mV dec⁻¹. CV and EIS showed that the sample had the largest electrochemically active surface area (121.3 mF cm⁻²) among the samples treated at different temperatures, with the smallest charge transfer resistance. In addition, the catalyst maintained high stability after 45 h of continuous operation. These results highlight the potential of NiMo/NF as a highly efficient and durable HER catalyst to help advance hydrogen energy technology. Full article

MoS₂ has emerged as a highly promising catalyst for the hydrogen evolution reaction (HER) owing to its exceptional catalytic properties. However, there is a pressing need to further enhance its reactivity and integrate oxygen evolution reaction (OER) capabilities to facilitate its industrial implementation. In this context, a dual-metal doping approach presents a straightforward and effective strategy to achieve superior catalytic performance. Systematic characterization and electrochemical evaluations reveal that the synergistic effects of Co and Fe doping significantly enhance both HER and OER activities, demonstrating remarkable potential for practical applications in energy conversion and storage systems. The unique flower-like architecture of the material endows it with a substantially enlarged surface area, which significantly increases the exposure of active sites and facilitates enhanced catalytic activity. Specifically, it achieves the low overpotentials of −127 and 292 mV at 10 mA cm⁻² for HER and OER in alkaline media, respectively, and demonstrates excellent stability over a 10 h test. This research provides valuable insights into the development of advanced materials capable of efficiently performing both HER and OER processes, paving the way for potential applications in sustainable energy technologies. Full article