Effects of surface fluoride modification on TiO2 for the photocatalytic oxidation of toluene.

In the present study, we investigated the influence of surface fluorine (F) on TiO2 for the photocatalytic oxidation (PCO) of toluene. TiO2 modified with different F content was prepared and tested. It was found that with the increasing of F content, the toluene conversion rate first increased and then decreased. However, CO2 mineralization efficiency showed the opposite trend. Based on the characterizations, we revealed that F substitutes the surface hydroxyl of TiO2 to form the structure of Ti-F. The presence of the appropriate amount of surface Ti-F on TiO2 greatly enhanced the separation of photogenerated carriers, which facilitated the generation of ·OH and promoted the activity for the PCO of toluene. It was further revealed that the increase of only ·OH promoted the conversion of toluene to ring-containing intermediates, causing the accumulation of intermediates and then conversely inhibited the ·OH generation, which led to the decrease of the CO2 mineralization efficiency. The above results could provide guidance for the rational design of photocatalysts for toluene oxidation.

Cu/TiO2 adsorbents modified by air plasma for adsorption-oxidation of H2S.

In this study, non-thermal plasma (NTP) was employed to modify the Cu/TiO2 adsorbent to efficiently purify H2S in low-temperature and micro-oxygen environments. The effects of Cu loading amounts and atmospheres of NTP treatment on the adsorption-oxidation performance of the adsorbents were investigated. The NTP modification successfully boosted the H2S removal capacity to varying degrees, and the optimized adsorbent treated by air plasma (Cu/TiO2-Air) attained the best H2S breakthrough capacity of 113.29 mg H2S/gadsorbent, which was almost 5 times higher than that of the adsorbent without NTP modification. Further studies demonstrated that the superior performance of Cu/TiO2-Air was attributed to increased mesoporous volume, more exposure of active sites (CuO) and functional groups (amino groups and hydroxyl groups), enhanced Ti-O-Cu interaction, and the favorable ratio of active oxygen species. Additionally, the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results indicated the main reason for the deactivation was the consumption of the active components (CuO) and the agglomeration of reaction products (CuS and SO42-) occupying the active sites on the surface and the inner pores of the adsorbents.

Highly efficient catalytic transfer hydrogenation for the conversion of nitrobenzene to aniline over PdO/TiO2: The key role of in situ switching from PdO to Pd.

The reduction of nitrobenzene to aniline is very important for both pollution control and chemical synthesis. Nevertheless, difficulties still remain in developing a catalytic system having high efficiency and selectivity for the production of aniline. Herein, it was found that PdO nanoparticles highly dispersed on TiO2 support (PdO/TiO2) functioned as a highly efficient catalyst for the reduction of nitrobenzene in the presence of NaBH4. Under favorable conditions, 95% of the added nitrobenzene (1 mmol/L) was reduced within 1 min with an ultra-low apparent activation energy of 10.8 kJ/mol by using 0.5%PdO/TiO2 as catalysts and 2 mmol/L of NaBH4 as reductants, and the selectivity to aniline even reached up to 98%. The active hydrogen species were perceived as dominant species during the hydrogenation of nitrobenzene by the results of isotope labeling experiments and ESR spectroscopic. A mechanism was proposed as follows: PdO activates the nitro groups and leads to in-situ generation of Pd, and the generated Pd acts as the reduction sites to produce active hydrogen species. In this catalytic system, nitrobenzene prefers to be adsorbed on the PdO nanoparticles of the PdO/TiO2 composite. Subsequently, the addition of NaBH4 results in in-situ generation of a Pd/PdO/TiO2 composite from the PdO/TiO2 composite, and the Pd nanoclusters would activate NaBH4 to generate active hydrogen species to attack the adsorbed nitro groups. This work will open up a new approach for the catalytic transfer hydrogenation of nitrobenzene to aniline in green chemistry.

Spatial confinement: An effective strategy to improve H2O and SO2 resistance of the expandable graphite-modified TiO2-supported Pt nanocatalysts for CO oxidation.

The expandable graphite (EG) modified TiO2 nanocomposites were prepared by the high shear method using the TiO2 nanoparticles (NPs) and EG as precursors, in which the amount of EG doped in TiO2 was 10 wt.%. Followed by the impregnation method, adjusting the pH of the solution to 10, and using the electrostatic adsorption to achieve spatial confinement, the Pt elements were mainly distributed on the exposed TiO2, thus generating the Pt/10EG-TiO2-10 catalyst. The best CO oxidation activity with the excellent resistance to H2O and SO2 was obtained over the Pt/10EG-TiO2-10 catalyst: CO conversion after 36 hr of the reaction was ca. 85% under the harsh condition of 10 vol.% H2O and 100 ppm SO2 at a high gaseous hourly space velocity (GHSV) of 400,000 hr-1. Physicochemical properties of the catalysts were characterized by various techniques. The results showed that the electrostatic adsorption, which riveted the Pt elements mainly on the exposed TiO2 of the support surface, reduced the dispersion of Pt NPs on EG and achieved the effective dispersion of Pt NPs, hence significantly improving CO oxidation activity over the Pt/10EG-TiO2-10 catalyst. The 10 wt.% EG doped in TiO2 caused the TiO2 support to form a more hydrophobic surface, which reduced the adsorption of H2O and SO2 on the catalyst, greatly inhibited deposition of the TiOSO4 and formation of the PtSO4 species as well as suppressed the oxidation of SO2, thus resulting in an improvement in the resistance to H2O and SO2 of the Pt/10EG-TiO2-10 catalyst.

Bacterial reduction and temperature increase of titanium dental implant models treated with a 445 nm diode laser: an in vitro study.

In this in vitro study, the use of a 445 nm diode laser was investigated for the decontamination of titanium dental implants. Different irradiation protocols and the effect of repetitive laser irradiation on temperature increase and decontamination efficacy were evaluated on titanium implant models. An automated setup was developed to realize a scanning procedure for a full surface irradiation to recapitulate a clinical treatment. Three irradiation parameter sets A (continuous wave, power 0.8 W, duty cycle (DC) 100%, and 5 s), B (pulsed mode, DC 50%, power 1.0 W, and 10 s), and C (pulsed mode, DC 10%, power 3.0 W, and 20 s) were used to treat the rods for up to ten consecutive scans. The resulting temperature increase was measured by a thermal imaging camera and the decontamination efficacy of the procedures was evaluated against Escherichia coli and Staphylococcus aureus, and correlated with the applied laser fluence. An implant's temperature increase of 10 °C was set as the limit accepted in literature to avoid thermal damage to the surrounding tissue in vivo. Repeated irradiation of the specimens resulted in a steady increase in temperature. Parameter sets A and B caused a temperature increase of 11.27 ± 0.81 °C and 9.90 ± 0.37 °C after five consecutive laser scans, respectively, while parameter set C resulted in a temperature increase of only 8.20 ± 0.53 °C after ten surface scans. The microbiological study showed that all irradiation parameter sets achieved a complete bacterial reduction (99.9999% or 6-log10) after ten consecutive scans, however only parameter set C did not exceed the temperature threshold. A 445 nm diode laser can be used to decontaminate dental titanium rods, and repeated laser irradiation of the contaminated areas increases the antimicrobial effect of the treatment; however, the correct choice of parameters is needed to provide adequate laser fluence while preventing an implant's temperature increase that could cause damage to the surrounding tissue.

Enhanced tooth bleaching with a hydrogen peroxide/titanium dioxide gel.

BACKGROUND: This study aimed to explore the effects of the titanium dioxide (TiO2) concentration and particle size in hydrogen peroxide (HP) on tooth bleaching effectiveness and enamel surface properties. METHODS: TiO2 at different concentrations and particle sizes was incorporated into 40% HP gel to form an HP/TiO2 gel. The specimens were randomly divided into 8 groups: C1P20: HP + 1% TiO2 (20 nm); C3P20: HP + 3% TiO2 (20 nm); C5P20: HP + 5% TiO2 (20 nm); C1P100: HP + 1% TiO2 (100 nm); C3P100: HP + 3% TiO2 (100 nm); C5P100: HP + 5% TiO2 (100 nm); C0: HP with LED; and C0-woL: HP without LED. Bleaching was conducted over 2 sessions, each lasting 40 min with a 7-day interval. The color differences (ΔE00), whiteness index for dentistry (WID), surface microhardness, roughness, microstructure, and composition were assessed. RESULTS: The concentration and particle size of TiO2 significantly affected ΔE00 and ΔWID values, with the C1P100 group showing the greatest ΔE00 values and C1P100, C3P100, and C5P100 groups showing the greatest ΔWID values (p < 0.05). No significant changes were observed in surface microhardness, roughness, microstructure or composition (p > 0.05). CONCLUSIONS: Incorporating 1% TiO2 with a particle size of 100 nm into HP constitutes an effective bleaching strategy to achieve desirable outcomes.

In-Situ Grown Nanocrystal TiO2 on 2D Ti3C2 Nanosheets with Anti-Tumor Activity from Photo-Sonodynamic Treatment and Immunology.

Introduction: Traditional cancer treatment strategies often have severe toxic side effects and poor therapeutic efficacy. To address the long-standing problems related to overcoming the complexity of tumors, we develop a novel nanozyme based on the in situ oxidation of 2D Ti3C2 structure to perform simultaneous phototherapy and sonodynamic therapy on tumors. Ti3C2 nanozymes exhibit multi-enzyme activity, including intrinsic peroxidase (POD) activities, which can react with H2O2 in the tumor microenvironment. This new material can construct Ti3C2/TiO2 heterostructures in vivo. Methods: Photothermal (PTT), sonodynamic (SDT) effects, and photoacoustic (PA) image-guided synergy therapy can be achieved. Finally, anticancer immune responses occur with this nanozyme. In vivo experiments revealed that the Ti3C2/TiO2 heterostructure inhibited tumor growth. Results: Complementarily, our results showed that the Ti3C2/TiO2 heterostructure enhanced the immunogenic activity of tumors by recruiting cytotoxic T cells, thereby enhancing the tumor ablation effect. Mechanistic studies consistently indicated that Reactive Oxygen Species (ROS) regulates apoptosis of HCC cells by modulating NRF2/OSGIN1 signaling both in vitro and in vivo. As a result, Ti3C2 nanozyme effectively inhibited tumor through its synergistic ability to modulate ROS and enhance immune infiltration of cytotoxic T cells in the tumor microenvironment. Discussion: These findings open up new avenues for enhancing 2D Ti3C2 nanosheets and suggest a new way to develop more effective sonosensitizers for the treatment of cancer.

Biological Effects of Double-Layered Hydroxyapatite and Zirconium Oxide Depositions on Titanium Surfaces.

Purpose: This study aimed to confirm the synergy effect of these two materials by evaluating osteoblast and antibacterial activity by applying a double-layered hydroxyapatite(HA) zirconium oxide(ZrO2) coating to titanium. Methods: The specimens used in this study were divided into four groups: a control group (polished titanium; group T) and three experimental groups: Group TH (RF magnetron sputtered HA deposited titanium), Group Z (ZrO2 ALD deposited titanium), and Group ZH (RF magnetron sputtered HA and ZrO2 ALD deposited titanium). The adhesion of Streptococcus mutans (S.mutans) to the surface was assessed using a crystal violet assay. The adhesion, proliferation, and differentiation of MC3T3-E1 cells, a mouse osteoblastic cell line, were assessed through a WST-8 assay and ALP assay. Results: Group Z showed a decrease in the adhesion of S. mutans (p < 0.05) and an improvement in osteoblastic viability (p < 0.0083). Group TH and ZH showed a decrease in adhesion of S. mutans (p < 0.05) and an increase in osteoblastic cell proliferation and cell differentiation (p < 0.0083). Group ZH exhibited the highest antibacterial and osteoblastic differentiation. Conclusion: In conclusion double-layered HA and ZrO2 deposited on titanium were shown to be more effective in inhibiting the adhesion of S. mutans, which induced biofilm formation, and increasing osteoblastic differentiation involved in osseointegration by the synergistic effect of the two materials.

Design and application of an ultrasensitive and selective tobromycin electrochemiluminescence aptasensor using MXene /Ni/Sm-LDH-based nanocomposite.

Using a chemiluminescence reaction between luminol and H2O2 in basic solution, an ultrasensitive electrochemiluminescence (ECL) aptasensor was developed for the determination of tobramycin (TOB), as an aminoglycoside antibiotic. Ti3C2/Ni/Sm-LDH-based nanocomposite effectively catalyzes the oxidation of luminol and decomposition of H2O2, leading to the formation of different reactive oxygen species (ROSs), thus amplifying the ECL signal intensity of luminol, which can be used for the determination of TOB concentration. To evaluate the performance of the electrochemiluminescence aptasensor and synthesized nanocomposite, different methods such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses were performed. The considerable specific area, large number of active sites, and enhanced electron transfer reaction on this nanocomposite led to the development of an ECL aptasensor with high sensitivity and electrocatalytic activity. After optimizing the preparation method and analysis conditions, the aptasensor revealed a wide linear response ranging from 1.0 pM to 1.0 µM with a detection limit of 18 pM, displaying outstanding accuracy, specificity, and response stability. The developed ECL sensor was found to be applicable to the determination of TOB in human serum samples and is anticipated to possess excellent clinical potentials for detecting other antibiotics, as well.

Recent advances and future trends in metal oxide photocatalysts for removal of pharmaceutical pollutants from wastewater: a comprehensive review.

The rapid and widespread increase in pharmaceutical micropollutants (PMPs) poses a significant and immediate threat to ecosystems and human health globally. With the demand for clean water becoming increasingly critical, particularly amid escalating global water scarcity challenges, there is an urgent need for innovative approaches. Among the potential solutions, metal oxide photocatalysts such as titanium dioxide-based (TiB) and zinc oxide-based (ZnB) have garnered attention due to their cost-effectiveness, efficient photodegradation capabilities, and inherent stability. This comprehensive review explores recent advancements in the application of TiB and ZnB for the removal of PMPs from wastewater. It examines the multifaceted impacts of PMPs on environmental and public health, evaluates various techniques for their removal, and assesses design strategies aimed at maximizing the photocatalytic efficiency of TiB and ZnB. The mechanisms responsible for the photocatalytic degradation of pharmaceutical micropollutants using TiB and ZnB photocatalysts are comprehensively detailed. Finally, the review outlines the prospects and challenges associated with the use of TiB and ZnB photocatalysts for the removal of PMPs from wastewater. It emphasizes their potential to effectively mitigate PMP contaminants and make substantial contributions to sustainable water management practices in the face of escalating environmental and public health concerns.

Self-powered sensing platform for monitoring uric acid in sweat using cobalt nanocrystal-graphene quantum dot-Ti3C2TX monolithic film electrode with excellent supercapacitor and sensing behavior.

The synthesis of cobalt nanocrystal-graphene quantum dot-Ti3C2TX monolithic film electrode (Co-GQD-Ti3C2TX) is reported via self-assembly of Ti3C2TX nanosheets induced by protonated arginine-functionalized graphene quantum dot and subsequent reduction of cobalt (III). The resulting Co-GQD-Ti3C2TX shows good monolithic architecture, mechanical property, dispersibility and conductivity. The structure achieves excellent supercapacitor and sensing behavior. The self-charging supercapacitor produced by printing viscous Co-GQD-Ti3C2TX hydrogel on the back of flexible solar cell surface provides high specific capacitance (296 F g-1 at 1 A g-1), high-rate capacity (153 F g-1 at 20 A g-1), capacity retention (98.1% over 10,000-cycle) and energy density (29.6 W h kg-1 at 299.9 W kg-1). The electrochemical chip produced by printing Co-GQD-Ti3C2TX hydrogel on paper exhibits sensitive electrochemical response towards uric acid. The increase of uric acid between 0.01 and 800 µM causes a linear increase in differential pulse voltammetry signal with a detection limit of 0.0032 µM. The self-powered sensing platform integrating self-charging supercapacitor, electrochemical chip and micro electrochemical workstation was contentedly applied to monitoring uric acid in sweats and shows one broad application prospect in wearable electronic health monitoring device.

Biomimetic HA-GO implant coating for enhanced osseointegration via macrophage M2 polarization-induced osteo-immunomodulation.

The pro-inflammatory/anti-inflammatory polarized phenotypes of macrophages (M1/M2) can be used to predict the success of implant integration. Hence, activating and inducing the transformation of immunocytes that promote tissue repair appears to be a highly promising strategy for facilitating osteo-anagenesis. In a previous study, titanium implants were coated with a graphene oxide-hydroxyapatite (GO-HA) nanocomposite via electrophoretic deposition, and the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was found to be significantly enhanced when the GO content was 2wt%. However, the effectiveness of the GO-HA nanocomposite coating in modifying the in vivo immune microenvironment still remains unclear. In this study, the effects of GO-HA coatings on osteogenesis were investigated based on the GO-HA-mediated immune regulation of macrophages. The HA-2wt%GO nanocomposite coatings exhibited good biocompatibility and favored M2 macrophage polarization. Meanwhile, they could also significantly upregulate IL-10 (anti-inflammatory factor) expression and downregulate TNF-α (pro-inflammatory factor) expression. Additionally, the microenvironment, which was established by M2 macrophages, favored the osteogenesis of BMSCs both in vivo and in vitro. These findings show that the GO-HA nanocomposite coating is a promising surface-modification material. Hence, this study provides a reference for the development of next-generation osteoimmunomodulatory biomaterials.

Coconut husk waste products valorization for fabrication of luminescent titanium dioxide NPs as powerful tool for photodecomposition and food born infection: A sustainable strategy.

Fabricating metal oxide nanoparticles has garnered much attention lately because creating safe chemicals, sustainable materials, economic processes, and renewable resources is becoming increasingly important. This research shows how TiO2 nanoparticles (NPs) could be generated in an ecologically responsible way using waste coconut husk with the help of tender coconut. This extract functions as both a reducing agent and a sealing agent. The investigation of TiO2 NPs exploited ultraviolet (UV), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and field-emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray (EDX) methods. The germicidal properties of TiO2 NPs against food-borne pathogenic strains were studied using the agar well method. Employing Congo red pigment, the photodecomposition behavior was investigated. The TiO2 NPs produced had a crystallite size measuring 16.2 nm. The average grain size of the sample, as measured by FE-SEM inspection, falls within the range of 15 to 25 nm. Impressive anti-germ effects against food-borne germs like Gram-positive (Staphylococcus aureus and Listeria monocytogenes), Gram-negative (Salmonella typhimurium and Escherichia coli) bacteria, and fungi (Candida albicans and Aspergillus niger) have been proved by the sustainable fabrication of TiO2 NPs. The catalytic effectiveness of Congo red decreased by 88% after 90 min. The findings suggest that sustainable synthesis of TiO2 NPs is an effective tool for food-borne germicides and photodecomposition behaviors.

Tailored Bioactive Glass Coating: Navigating Devitrification Toward a Superior Implant Performance.

The development of well-adherent, amorphous, and bioactive glass coatings for metallic implants remains a critical challenge in biomedical engineering. Traditional bioactive glasses are susceptible to crystallization and exhibit a thermal expansion mismatch with implant materials. This study introduces a novel approach to overcome these limitations by employing systematic Na2O substitution with CaO in borosilicate glasses. In-depth structural analysis (MD simulations, Raman spectroscopy, and NMR) reveals a denser network with smaller silicate rings, enhancing thermal stability, reducing thermal expansion, and influencing dissolution kinetics. This tailored composition exhibited optimal bioactivity (in vitro formation of bone-like apatite within 3 days) and a coefficient of thermal expansion closely matching Ti-6Al-4V, a widely used implant material. Furthermore, a consolidation process, meticulously designed with insights from crystallization kinetics and the viscosity-temperature relationship, yielded a crack-free, amorphous coating on Ti-6Al-4V substrates. This novel coating demonstrates excellent cytocompatibility and strong antibacterial action, suggesting superior clinical potential compared with existing technologies.

Preparation and properties of silver-carrying nano-titanium dioxide antimicrobial agents and silicone composite.

The characteristics of dopamine self-polymerization were used to cover the nano-titanium dioxide (TiO2) surface and produce nano-titanium dioxide-polydopamine (TiO2-PDA). The reducing nature of dopamine was then used to reduce silver nitrate to silver elemental particles on the modified nano-titanium dioxide: The resulting TiO2-PDA-Ag nanoparticles were used as antimicrobial agents. Finally, the antibacterial agent was mixed with silicone to obtain an antibacterial silicone composite material. The composition and structure of antibacterial agents were analyzed by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron energy spectroscopy, and X-ray diffraction. Microscopy and the antibacterial properties of the silicone antibacterial composites were studied as well. The TiO2-PDA-Ag antimicrobial agent had good dispersion versus nano-TiO2. The three were strongly combined with obvious characteristic peaks. The antibacterial agents were evenly dispersed in silicone, and the silicone composite has excellent antibacterial properties. Bacillus subtilis (B. subtilis) adhesion was reduced from 246 × 104 cfu/cm2 to 2 × 104 cfu/cm2, and colibacillus (E. coli) reduced from 228 × 104 cfu/cm2 leading to bacteria-free adhesion.

Controllable synthesis of TiO2/graphene composites for human voice recognition in strain sensor.

Low-dimensional materials have demonstrated strong potential for use in diverse flexible strain sensors for wearable electronic device applications. However, the limited contact area in the sensing layer, caused by the low specific surface area of typical nanomaterials, hinders the pursuit of high-performance strain-sensor applications. Herein, we report an efficient method for synthesizing TiO2-based nanocomposite materials by directly using industrial raw materials with ultrahigh specific surface areas that can be used for strain sensors. A kinetic study of the self-seeded thermal hydrolysis sulfate process was conducted for the controllable synthesis of pure TiO2 and related TiO2/graphene composites. The hydrolysis readily modified the crystal form and morphology of the prepared TiO2 nanoparticles, and the prepared composite samples possessed a uniform nanoporous structure. Experiments demonstrated that the TiO2/graphene composite can be used in strain sensors with a maximum Gauge factor of 252. In addition, the TiO2/graphene composite-based strain sensor showed high stability by continuously operating over 1,000 loading cycles and aging tests over three months. It also shows that the fabricated strain sensors have the potential for human voice recognition by characterizing letters, words, and musical tones.

Enhancing Bactericidal Properties of Ti6Al4V Surfaces through Micro and Nano Hierarchical Laser Texturing.

Orthopedic and dental implants made from Ti6Al4V are widely used due to their excellent mechanical properties and biocompatibility. However, the long-term performance of these implants can be compromised by bacterial infections. This study explores the development of hierarchically textured surfaces with enhanced bactericidal properties to address such challenges. Hierarchical surface structures were developed by combining microscale features produced by a microsecond laser and superimposed submicron features produced using a femtosecond laser. Microscale patterns were produced by the pulsed laser surface melting process, whereas submicrometer laser-induced periodic surface structures were created on top of them by femtosecond laser processing. Escherichia coli bacterial cells were cultured on the textured surface. After 24 h, a staining analysis was performed using SYTO9 and PI dyes to investigate the samples with a confocal microscope for live dead assays. Results showed bacterial colony formation onto the microscale surface textures with live bacterial cells, whereas the hierarchical surface textures display segregated and physically damaged bacterial cell attachments on surfaces. The hierarchical surface textures showed ∼98% dead bacterial cells due to the combined effect of its multiscale surface features and oxide formation during the laser processing steps. The efficacy of hierarchical surface textures in enhancing the antibacterial behavior of Ti6Al4V implants is evident from the conducted research. Such laser-based surface treatments can find potential applications in different industrial sectors.

Insights on the efficiency and contribution of single active species in photocatalytic degradation of tetracycline: Priority attack active sites, intermediate products and their toxicity evaluation.

Photocatalysis has been proven to be an excellent technology for treating antibiotic wastewater, but the impact of each active species involved in the process on antibiotic degradation is still unclear. Therefore, the S-scheme heterojunction photocatalyst Ti3C2/g-C3N4/TiO2 was successfully synthesized using melamine and Ti3C2 as precursors by a one-step calcination method using mechanical stirring and ultrasound assistance. Its formation mechanism was studied in detail through multiple characterizations and work function calculations. The heterojunction photocatalyst not only enabled it to retain active species with strong oxidation and reduction abilities, but also significantly promoted the separation and transfer of photo-generated carriers, exhibiting an excellent degradation efficiency of 94.19 % for tetracycline (TC) within 120 min. Importantly, the priority attack sites, degradation pathways, degradation intermediates and their ecological toxicity of TC under the action of each single active species (·O2-, h+, ·OH) were first positively explored and evaluated through design experiments, Fukui function theory calculations, HPLC-MS, Escherichia coli toxicity experiments, and ECOSAR program. The results indicated that the preferred attack sites of ·O2- on TC were O20, C7, C11, O21, and N25 atoms with high f+ value. The toxicity of intermediates produced by ·O2- was also lower than those produced by h+ and ·OH.

Nanosensors Based on Bimetallic Plasmonic Layer and Black Phosphorus: Application to Urine Glucose Detection.

This paper presents a new biosensor design based on the Kretschmann configuration, for the detection of analytes at different refractive indices. Our studied design consists of a TiO2/SiO2 bi-layer sandwiched between a BK7 prism and a bimetallic layer of Ag/Au plasmonic materials, covered by a layer of black phosphorus placed below the analyte-containing detection medium. The different layers of our structure and analyte detection were optimized using the angular interrogation method. High performance was achieved, with a sensitivity of 240 deg/RIU and a quality factor of 34.7 RIU-1. This biosensor can detect analytes with a wide refractive index range between 1.330 and 1.347, such as glucose detection in urine samples using a refractive index variation of 10-3. This capability offers a wide range of applications for biomedical and biochemical detection and selectivity.

Gas-Sensing Performance of Metal Oxide Heterojunction Materials for SF6 Decomposition Gases: A DFT Study.

The online monitoring of GIS equipment can be realized through detecting SF6 decomposition gasses. Metal oxide heterojunctions are widely used as gas-sensing materials. In this study, the structural and electrical properties of In2O3-ZnO and TiO2-ZnO heterojunctions were analyzed based on density functional theory calculations. After heterojunction structural optimization, the electrical conductivity of these two heterojunctions was enhanced compared to each intrinsic model, and the electrical conductivity is ranked as follows: In2O3-ZnO heterojunction > TiO2-ZnO heterojunction. The gas-sensing response of these two heterojunctions to four SF6 decomposition gasses, H2S, SO2, SOF2, and SO2F2, was investigated. For gas adsorption systems, the adsorption energy, charge transfer, density of states, charge difference density, and frontier molecular orbitals were calculated to analyze the adsorption and gas-sensing performance. For gas adsorption on the In2O3-ZnO heterojunction surface, the induced conductivity changes are in the following order: H2S > SO2F2 > SOF2 > SO2. For gas adsorption on the TiO2-ZnO heterojunction surface, H2S and SOF2 increase conductivity, and SO2 and SO2F2 decrease conductivity.