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In this study, a simple and competent metal–organic framework (MOF)-based nickel foam (NF)-supported three-dimensional (3D) immunosensor (Ab-NH2-MIL-88B(Fe2Co)-MOF/NF) was constructed and utilized for the specific recognition of the biomarker cardiac troponin (I) (cTnI). In the present work, biosensor fabrication was progressed through the modification of the NF substrate with the MOF material (NH2-MIL-88B(Fe2Co)-MOF) to enable an amine-functionalized electrode. This amine-functionalized NF electrodes (NH2-MIL-88B(Fe2Co)-MOF/NF) were then biointerfaced with anti-cTnI antibodies, which ended up as Ab-NH2-MIL-88B(Fe2Co)-MOF/NF electrodes. Analytical executions of the constructed bioelectrode were investigated for the quantitative analysis of cTnI in both buffered and serum solutions. Then, the electrochemical studies were carried out using the electrochemical impedance spectroscopy (EIS) method by monitoring changes concerning the charge transfer resistance (Rct) characteristics. The limit of detection (LOD) of the Ab-NH2-MIL-88B(Fe2Co)-MOF/NF immunosensor was achieved to be 13 fg/mL with great specificity. This kind of immunosensor imparts a new platform for the construction and application of MOF-hybrid 3D electrode materials with enhanced electrochemical behavior in cTnI sensing for the first time.

A Li-rich layered oxide (LLO) cathode with morphology-dependent electrochemical performance with the composition Li1.23Mn0.538Ni0.117Co0.114O2in three different microstructural forms, namely, randomly shaped particles, platelets, and nanofibers, is synthesized through the solid-state reaction (SSR-LLO), hydrothermal method (HT-LLO), and electrospinning process (ES-LLO), respectively. Even though the cathodes possess different morphologies, structurally they are identical. The elemental dispersion studies using energy-dispersive X-ray spectroscopy mapping in scanning transmission electron microscopy show uniform distribution of elements. However, SSR-LLO and ES-LLO nanofibers show slight Co-rich regions. The electrochemical studies of LLO cathodes are evaluated in terms of charging/discharging, C-rate capability, and cyclic stability performances. A high reversible capacity of 275 mA h g–1is achieved in the fibrous LLO cathode which also demonstrates good high-rate capability (80 mA h g–1at 10 C-rate). These capacities and rate capabilities are superior to those of SSR-LLO [210.5 mA h g–1(0.1 C-rate) and 4 mA h g–1(3 C-rate)] and HT-LLO [242 mA h g–1(0.1 C-rate) and 22 mA h g–1(10 C-rate)] cathodes. The ES-LLO cathode exhibits 88% capacity retention after 100 cycles at 1 C-rate. A decrease in voltage on cycling is found to be common in all three cathodes; however, minimal voltage decay and capacity loss are observed in ES-LLO upon cycling. Well-connected small LLO particles constituting fibrous microstructural forms in ES-LLO provide an enhanced electrolyte/cathode interfacial area and reduced diffusion path length for Li+. This, in turn, facilitates superior electrochemical performance of the electrospun Co-low LLO cathode suitable for quick charge battery applications.

Herein, we have reported on the efficiency of inorganic Zn3N2nanoparticles for labeling plant cells and animal cells toward imaging applications with negligible toxicity. We have synthesized zinc nitride (Zn3N2) colloidal nanoparticles with an average size of 25 nm at room temperature. The optical band gap of the prepared Zn3N2nanoparticles is 2.8 eV and gives a visible range emission at 415 nm. With the addition of Zn3N2colloids to organic dyes such as protoporphyrin, flavin adenine dinucleotide, fluorescein, and neutral red, the emission intensity of the organic dyes enhanced from 3 to 20 times. The molecular simulation and lifetime studies evidence the possibility of energy transfer from zinc nitride to organic dyes. The enhancement of dye intensity in the presence of Zn3N2enhanced the vicinity of the cellular environment during confocal imaging of plant cells and animal cells. The detailed results suggested Zn3N2for bioimaging and biosensor applications.

Asphaltene deposition in petroleum refineries is known to be problematic as it reduces efficiency and may lead to structural failure or production downtime. Though several successful approaches have been utilized to limit deposition through the addition of dispersants and inhibitors to petroleum, these methods require constant intervention and are often expensive. In this study, we demonstrate an innovative technique to engineer the surface chemistry of pipeline steels to inhibit asphaltene deposition. Pack aluminization, a standard industrial-scale chemical vapor deposition process, is employed at a low temperature of 600 °C to aluminize API 5L X65 high strength pipe steel substrates. The results showed deposit-free steel surfaces after high-pressure and high-temperature fouling experiments. The improvement is attributed to the formation of an aluminide intermetallic phase of Fe2Al5, which changes the native oxide chemistry to favor alumina over hematite. The continuous passivating oxide scale, acting as a protective barrier, mitigates asphaltene deposition and sulfidic corrosion. Because this process is based on alloying the surface of the steel and is not a coating with a weakly adhered interface, it is not prone to delamination, and it can be re-formed when damaged within the aluminized region. The combination of low-cost processing and improved antifouling characteristics makes surface chemistry modification of steel a promising preventative approach against asphaltene deposition.

As the demand for sustainable energy continues to rise, electrocatalysis has become increasingly prominent in the advancement of clean energy technologies. By scrutinizing the material to function as a multifunctional catalyst, the effectiveness of energy conversion processes is significantly enhanced. This study focuses on harnessing graphene/WS2van der Waals heterostructures for overall water splitting and fuel cell applications, using transition metals (TMs) from Sc–Zn as single-atom catalysts (SACs). Additionally, the research explores the synergistic effect of nitrogen doping combined with SACs to modify the material into multifunctional catalysts. The stability of all TMs as SACs in the vdW heterostructure (TM@GW) and nitrogen-doped TM@GW (TM@NGW) is validated with negative cohesive and formation energies, and thermodynamic stability is also corroborated with ab initiomolecular dynamics (AIMD) analysis at both 300 and 500 K for 5 ps. The observed electrocatalytic performance of TM@GW and TM@NGW depicts that the Ni@NGW system exhibits trifunctional property with the lowest overpotentials {ηHER; ηOER;ηORR= 0.21; 0.42; 0.27 V}. Additionally, the Cr@NGW material displays bifunctional catalytic activity for the OER and ORR, with overpotentials of 0.53 and 0.37 V, respectively. The synergistic effect between N doping and SACs is further studied with the d, p band centers and density of states calculations. Furthermore, the scaling relation between the adsorption of intermediates and reaction kinetics is studied, which validates the coaction of N and SACs in the TM@NGW heterostructure. This study demonstrates that the inclusion of SACs and nitrogen atoms in the GW heterostructure significantly enhances the catalytic performance by approximately 26%, effectively transforming the system into a multifunctional catalyst. These findings emphasize the role of SACs in vdW heterostructures and N doping effects, providing valuable insights to guide the design of advanced catalysts for water splitting and fuel cell applications.

Sialic acid-conjugated nanocarriers have emerged as attractive biomarkers with promising biomedical applications. The translation of these nanocarriers into clinical applications requires in-depth assessment in animal models. However, due to the complexity, ethical concerns, and cost of the high-order animal system, there is an immediate need of information-rich simple animal models to decipher the biological significance. Herein, we performed in vivo head-to-head comparison of Neu5Acα(2–6) and α(2–3)Gal conjugated quantum dots (QDs) toxicity, biodistribution, and sequestration in wild-type zebrafish (Danio rerio) and mouse model (C57BL). The fluorescent properties and cadmium composition of quantum dots were used to map the blood clearance, biodistribution, and sequestration of the sialylated QDs in major organs of both models. We observed that α(2–6) sialylated QDs preferentially have prolonged circulating half-life and broader biodistribution in both models. On the contrary, α(2–3) sialic acid and galactose-conjugated QDs have shortened blood circulation time and are sequestered in the liver, and cleared after several hours in both models. These results demonstrate the applicability of the zebrafish and sialylated QDs to target specific organs, as well as drug delivery and biomedical diagnostics.

Regeneration of full-thickness wounds without scar formation is a multifaceted process, which depends on in situ dynamic interactions between the tissue-engineered skin substitutes and a newly formed reparative tissue. However, the majority of the tissue-engineered skin substitutes used so far in full-thickness wound healing cannot mimic the natural extracellular matrix (ECM) complexity and thus are incapable of providing a suitable niche for endogenous tissue repair. Herein, we demonstrated a simple approach to fabricate porous hybrid ECM sponges (HEMS) using a placental ECM and silk fibroin for full-thickness wound healing. HEMS with retained cytokines/growth factors provided a noncytotoxic environment in vitro for human foreskin fibroblasts (HFFs), human epidermal keratinocytes (HEKs), and human amniotic membrane-derived stem cells to adhere, infiltrate, and proliferate. Interestingly, HEMS-conditioned media accelerated the migration of HFFs and HEKs owing to the presence of cytokines/growth factors. Also, the ex vivo chick chorioallantoic membrane assay of HEMS demonstrated its excellent vascularization potential by inducing and supporting blood vessels. Additionally, HEMS when subcutaneously implanted demonstrated no severe immune response to the host. Furthermore, HEMS implanted in full-thickness wounds in a rat model showed augmented healing progression with well-organized epidermal–dermal junctions via pronounced angiogenesis, accelerated migration of HFFs/HEKs, enhanced granulation tissue formation, and early re-epithelialization. Taken together, these findings show that porous HEMS ornamented with cytokines/growth factors having superior physicomechanical properties may be an appropriate skin substitute for full-thickness cutaneous wounds.

A novel scaffold for effective wound healing treatment was developed utilizing natural product bearing collagen-based biocompatible electrospun nanofibers. Initially, ostholamide (OSA) was synthesized from osthole (a natural coumarin), characterized by 1H, 13C, DEPT-135 NMR, ESI-MS, and FT-IR spectroscopy analysis. OSA was incorporated into polyhydroxybutyrate (PHB) and gelatin (GEL), which serve as templates for electrospun nanofibers. The coating of OSA-PHB-GEL nanofibers with collagen resulted in PHB-GEL-OSA-COL nanofibrous scaffold which mimics extracellular matrix and serves as an effective biomaterial for tissue engineering applications, especially for wound healing. PHB-GEL-OSA-COL, along with PHB-GEL-OSA and collagen film (COLF), was characterized in vitroand in vivoto determine its efficacy. The developed PHB-GEL-OSA-COL nanofibers posed an impressive mechanical stability, an essential requirement for wound healing. The presence of OSA had contributed to antimicrobial efficacy. These scaffolds exhibited efficient antibacterial activity against common wound pathogens, Pseudomonas aeruginosa(P. aeruginosa) and Staphylococcus aureus(S. aureus). The zones of inhibition were observed to be 14 ± 22 and 10 ± 2 mm, respectively. It was observed that nanofibrous scaffold had the ability to release OSA in a controlled manner, and hence, OSA would be present at the site of application and exhibit bioactivity in a sustained manner. PHB-GEL-OSA-COL nanofiber was determined to be stable against enzymatic degradation, which is the most important parameter for promoting proliferation of cells contributing to repair and remodeling of tissues during wound healing applications. As hypothesized, PHB-GEL-OSA-COL was observed to imbibe excellent cytocompatibility, which was determined using NIH 3T3 fibroblast cell proliferation studies. PHB-GEL-OSA-COL exhibited excellent wound healing efficacy which was confirmed using full thickness excision wound model in Wistar rats. The rats treated with PHB-GEL-OSA-COL nanofibrous scaffold displayed enhanced healing when compared to untreated control. Both in vitroand in vivoanalysis of PHB-GEL-OSA-COL presents a strong case of therapeutic biomaterial suiting wound repair and regeneration.

A detail study concerning the strain (tensile) dependent electrical conductivity of elastomeric composites is reported in this present paper. Multiwall carbon nanotubes (CNT), conducting carbon black (CB), and their combinations were considered as conducting filler in cross-linked natural rubber matrix. The loadings of the fillers were considered from 3 to 11 phr (filler concentration close to their percolation threshold). Without hindering the elastic nature of the composite (reversible stretchability up to several 100%), the change of relative resistance, ΔR/R0(ΔRis the change in the resistance with respect to strain and R0is the initial resistance of the sample) of the CB filled composites was found to be as much as ∼1300 at around 120% elongation. This value is much higher than any other reported values obtained from conducting polymeric composites. It was found that CNT offered a strong strain dependent character in the regime 100% to 150% elongation, whereas, the carbon black filled natural rubber showed strong strain dependencies at 50% to 100% elongation strain. The combination of two different fillers could be exploited to tailor and manipulate the sensing operating regime from 50% to 150% strain depending on the ratios of the two filler system. Additionally, after several loading–unloading cycles, the conductivity of the sample was very stable for CB filled system but for CNT filled system the conductivity of the sample was altered. This type of elastic materials could be used in structural health monitoring, sensors in different dynamic elastomeric parts like tires, valves, gaskets, engine mounts, etc.

Materials which possess high specific capacitance in device configuration with low cost are essential for viable application in supercapacitors. Herein, a flexible high-energy supercapacitor device was fabricated using porous activated high-surface-area carbon derived from aloe leaf (Aloe vera) as a precursor. The A. veraderived activated carbon showed mesoporous nature with high specific surface area of ∼1890 m2/g. A high specific capacitance of 410 and 306 F/g was achieved in three-electrode and symmetric two-electrode system configurations in aqueous electrolyte, respectively. The fabricated all-solid-state device showed a high specific capacitance of 244 F/g with an energy density of 8.6 Wh/kg. In an ionic liquid electrolyte, the fabricated device showed a high specific capacitance of 126 F/g and a wide potential window up to 3 V, which results in a high energy density of 40 Wh/kg. Furthermore, it was observed that the activation temperature has significant role in the electrochemical performance, as the activated sample at 700 °C showed best activity than the samples activated at 600 and 800 °C. The electron microscopic images (FE-SEM and HR-TEM) confirmed the formation of pores by the chemical activation. A fabricated supercapacitor device in ionic liquid with 3 V could power up a red LED for 30 min upon charging for 20s. Also, it is shown that the operation voltage and capacitance of flexible all-solid-state symmetric supercapacitors fabricated using aloe-derived activated carbon could be easily tuned by series and parallel combinations. The performance of fabricated supercapacitor devices using A. veraderived activated carbon in all-solid-state and ionic liquid indicates their viable applications in flexible devices and energy storage.

A bioinorganic nanohybrid catalyst was synthesized by combining esterase with a platinum nanoparticle (PtNP). The combination of two catalysts resulted in enhanced catalytic activities, esterase hydrolysis, and hydrogenation in PtNPs, as compared to each catalyst alone. This hybrid catalyst can be successfully used in the multistep synthesis of acetaminophen (paracetamol), an analgesic and antipyretic drug, in a one-pot reaction with high yield and efficacy within a short time, demonstrating that the nanobiohybrid catalyst offers advantages in the synthesis of fine chemicals in industrial applications.

Current strategies of bilayer technology have been aimed mainly at the enhancement of bioactivity, mechanical property and corrosion resistance. In the present investigation, the electropolymerization of poly(3,4-ethylenedioxypyrrole-co-3,4-ethylenedioxythiophene) (P(EDOP-co-EDOT)) with various feed ratios of EDOP/EDOT on surgical grade stainless steel (316L SS) and the successive electrodeposition of strontium (Sr2+), magnesium (Mg2+) and cerium (Ce3+) (with 0.05, 0.075 and 0.1 M Ce3+) substituted porous hydroxyapatite (M-HA) are successfully combined to produce the bioactive and corrosion resistance P(EDOP-co-EDOT)/M-HA bilayer coatings for orthopedic applications. The existence of as-developed coatings was confirmed by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), proton nuclear magnetic resonance spectroscopy (1H NMR), high resolution scanning electron microscopy (HRSEM), energy dispersive X-ray analysis (EDAX) and atomic force microscopy (AFM). Also, the mechanical and thermal behavior of the bilayer coatings were analyzed. The corrosion resistance of the as-developed coatings and also the influence of copolymer (EDOP:EDOT) feed ratio were studied in Ringer’s solution by electrochemical techniques. The as-obtained results are in accord with those obtained from the chemical analysis using inductively coupled plasma atomic emission spectrometry (ICP-AES). In addition, the antibacterial activity, in vitrobioactivity, cell viability and cell adhesion tests were performed to substantiate the biocompatibility of P(EDOP-co-EDOT)/M-HA bilayer coatings. On account of these investigations, it is proved that the as-developed bilayer coatings exhibit superior bioactivity and improved corrosion resistance over 316L SS, which is potential for orthopedic applications.

The utilization of hydrogen (H2) as a fuel source is hindered by the limited infrastructure and storage requirements. In contrast, ammonia (NH3) offers a promising solution as a hydrogen carrier due to its high energy density, liquid storage capacity, low cost, and sustainable manufacturing. NH3has garnered significant attention as a key component in the development of next-generation refueling stations, aligning with the goal of a carbon-free economy. The electrochemical nitrogen reduction reaction (ENRR) enables the production of NH3from nitrogen (N2) under ambient conditions. However, the low efficiency of the ENRR is limited by challenges such as the electron-stealing hydrogen evolution reaction (HER) and the breaking of the stable N2triple bond. To address these limitations and enhance ENRR performance, we prepared Au@Cu2–xSe electrocatalysts with a core@shell structure using a seed-mediated growth method and a facile hot-injection method. The catalytic activity was evaluated using both an aqueous electrolyte of KOH solution and a nonaqueous electrolyte consisting of tetrahydrofuran (THF) solvent with lithium perchlorate and ethanol as proton donors. ENRR in both aqueous and nonaqueous electrolytes was facilitated by the synergistic interaction between Au and Cu2–xSe (copper selenide), forming an Ohmic junction between the metal and p-type semiconductor that effectively suppressed the HER. Furthermore, in nonaqueous conditions, the Cu vacancies in the Cu2–xSe layer of Au@Cu2–xSe promoted the formation of lithium nitride (Li3N), leading to improved NH3production. The synergistic effect of Ohmic junctions and Cu vacancies in Au@Cu2–xSe led to significantly higher ammonia yield and faradaic efficiency (FE) in nonaqueous systems compared to those in aqueous conditions. The maximum NH3yields were approximately 1.10 and 3.64 μg h–1cm–2, with the corresponding FE of 2.24 and 67.52% for aqueous and nonaqueous electrolytes, respectively. This study demonstrates an attractive strategy for designing catalysts with increased ENRR activity by effectively engineering vacancies and heterojunctions in Cu-based electrocatalysts in both aqueous and nonaqueous media.

Nanostructured silicon hybrid solar cells are promising candidates for a new generation photovoltaics because of their light-trapping abilities and solution processes. However, the performance of hybrid organic/Si nanostructure solar cells is hindered because of carrier recombination at surface and poor coverage of organic material poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on nanostructures. Here we demonstrate low-pressure-assisted coating method of PEDOT:PSS on surface-modified silicon nanotips with broadband light-trapping characteristics to improve interface property and to achieve high-efficiency hybrid solar cells through a solution process. The approach enhances the effective minority-carrier lifetime and the coverage of PEDOT:PSS on the surface of nanostructures. Hybrid solar cells fabricated with surface-modified nanotips exhibit a high fill factor of 70.94%, short-circuit current density of 35.36 mA/cm2, open-circuit voltage of 0.528 V, and power conversion efficiency of 13.36%. The high efficiency and the high fill factor are achieved because of conformal coating of PEDOT:PSS via a low-pressure-assisted coating process, excellent light harvesting without sacrificing the minority-carrier lifetime, and efficient charge separation/collection of photogenerated carriers.

Ammonia is a suitable hydrogen carrier with each molecule accounting for up to 17.65% of hydrogen by mass. Among various potential ammonia production methods, we adopt the photoelectrochemical (PEC) technique, which uses solar energy as well as electricity to efficiently synthesize ammonia under ambient conditions. In this article, we report MoS2@La2Zr2O7heterostructures designed by incorporating two-dimensional (2D)-MoS2nanoflakes on La2Zr2O7nanofibers (MoS2@LZO) as photoelectrocatalysts. The MoS2@LZO heterostructures are synthesized by a facile hydrothermal route with electrospun La2Zr2O7nanofibers and Mo precursors. The MoS2@LZO heterostructures work synergistically to amend the drawbacks of the individual MoS2electrocatalysts. In addition, the harmonious activity of the mixed phase of pyrochlore/defect fluorite-structured La2Zr2O7nanofibers generates an interface that aids in increased electrocatalytic activity by enriching oxygen vacancies in the system. The MoS2@LZO electrocatalyst exhibits an enhanced Faradaic efficiency and ammonia yield of approximately 2.25% and 10.4 μg h–1cm–2, respectively, compared to their corresponding pristine samples. Therefore, the mechanism of improving the PEC ammonia production performance by coupling oxygen-vacant sites to the 2D-semiconductor-based electrocatalysts has been achieved. This work provides a facile strategy to improve the activity of PEC catalysts by designing an efficient heterostructure interface for PEC applications.