One-step Procedure Research Articles

ENGINEERED CHITOSAN NANOPARTICLES FOR ENCAPSULATION OF THYMOL

This study successfully obtained chitosan thymol nanoparticles using an electrohydrodynamic technique, which is a simple one-step procedure. The morphological and physical characterization, antioxidant, and antimicrobial activity assessments of electrosprayed thymol-loaded chitosan nanoparticles (CTNPs) were carried out. The ABTS assay and the agar well diffusion test were used to determine the antioxidant and antimicrobial activities of the CTNP samples, respectively. The results showed that CTNPs possessed efficient antimicrobial capacity against B. cereus, S. aureus, E. coli, and S. typhimurium. CTNPs indicated a radical scavenging activity of 90% regarding the ABTS assay. CTNPs with biological activities could be an effective alternative for practical food safety and health applications. In this study, the use of electrohydrodynamic atomization technique to produce biopolymer nanoparticles present a novel approach for encapsulating thymol-like volatile active agents.

Cholesteryl Phenolipids as Potential Biomembrane Antioxidants

The lipophilization of polyphenols (phenolipids) may increase their affinity for membranes, leading to better antioxidant protection. Cholesteryl esters of caffeic, dihydrocaffeic, homoprotocatechuic and protocatechuic acids were synthetized in a one-step procedure with good to excellent yields of ~50–95%. After evaluation of their radical scavenging capacity by the DPPH method and establishing the anodic peak potential by cyclic voltammetry, their antioxidant capacity against AAPH-induced oxidative stress in soybean PC liposomes was determined. Their interaction with the liposomal membrane was studied with the aid of three fluorescence probes located at different depths in the membrane. The cholesteryl esters showed a better or similar radical scavenging capacity to that of α-tocopherol and a lower anodic peak potential than the corresponding parental phenolic acids. Cholesteryl esters were able to protect liposomes to a similar or greater extent than α-tocopherol. However, despite their antiradical capacity and being able to penetrate and orientate in the membrane in a parallel position to phospholipids, the antioxidant efficiency of cholesteryl esters was deeply dependent on the phenolipid polyphenolic moiety structure. When incorporated during liposome preparation, cholesteryl protocatechuate and caffeate showed more than double the activity of α-tocopherol. Thus, cholesteryl phenolipids may protect biomembranes against oxidative stress to a greater extent than α-tocopherol.

Autologous platelet-rich plasma and fibrin-augmented minced cartilage implantation in chondral lesions of the knee leads to good clinical and radiological outcomes after more than 12 months: A retrospective cohort study of 71 patients.

The treatment of cartilage lesions remains a challenge. Matrix-associated autologous chondrocyte implantation has evolved to become the gold standard procedure. However, this two-step procedure has crucial disadvantages, and the one-step minced cartilage procedure has gained attention. This retrospective study aimed to evaluate the clinical and radiological outcome of an all-autologous minced cartilage technique in cartilage lesions at the knee joint. In this retrospective cohort study, 71 patients (38.6 years ± 12.0, 39,4% female) with a magnetic resonance imaging (MRI) confirmed grade III-IV cartilage defect at the medial femur condyle (n = 20), lateral femur condyle (n = 2), lateral tibia plateau (n = 1), retropatellar (n = 28) and at the trochlea (n = 20) were included. All patients were treated with an all-autologous minced cartilage procedure (AutoCart™). Clinical knee function was evaluated by the Tegner score, visual analogue scale, the subjective and objective evaluation form of the International Knee Documentation Committee and the Knee Injury and Osteoarthritis Outcome Score (KOOS). MRI analyses were performed by magnetic resonance observation of cartilage repair tissue (MOCART) 2.0 knee score. Follow-up examination was 13.7 ± 4.2 (12-24) months postoperative. All clinical scores significantly improved after surgical intervention (p < 0.0001), especially the subgroup sports and recreation of KOOS showed clear changes from baseline in the follow-up examination. In the postoperative MRI evaluation, 39 of 71 patients showed a complete fill of the cartilage defect without subchondral changes in 78% of the patients in the MOCART 2.0 score in the follow-up analysis. None of the patients showed adverse effects, which are linked to the minced cartilage procedure during the time of follow-up. An all-autologous minced cartilage technique for chondral lesions at the knee joint seems to be an effective and safe treatment method with good clinical and radiological short-term results. Level IV.

Influence of gadolinium substitution on the crystal structure of NiO and its maximized photocatalytic degradation activity on tetracycline and direct yellow pollutants

Gadolinium-substituted NiO crystal structures with excellent stability were utilized for the first time to degrade antibiotic and organic dye pollutants. A simple hydrothermal technique was used to synthesize different concentrations of Gd3+ substituted NiO, and the catalysts were thoroughly characterized using sophisticated techniques to explore the influence of Gd3+ on the crystal structure and optical characteristics of NiO. The 1.5% Gd3+ substituted NiO showed outstanding photocatalytic activity on tetracycline and direct yellow degradation, with percentages of 90.72 and 95.5%, respectively. The improvement of photocatalytic degradation efficiency is primarily due to the suppression of photoinduced electron and hole recombination via the creation of Gd3+ as the inner energy band state below the conduction band. The recycling experiments revealed that the catalyst is more stable, with no indication of loss after ten cycles. Scavenging investigations also demonstrated that superoxide and holes were responsible for the efficient degradation of pollutants.

An efficient one-step synthesis of a new series of mutifunctional olefins and direct hydroxymethylation of α-substituted β-keto esters

An efficient one-step procedure for the synthesis of a new series of multifunctional olefins by condensation of α-substituted β-diketones as well as β-phosphonoesters and benzoylated β-ketoesters with formaldehyde, using potassium carbonate in refluxing THF, followed by a deacylation reaction, is herein described. In contrast, the α-substituted β-keto esters, bearing an acyl moiety, only undergo a hydroxymethylation reaction, with no metal catalysts/activating agents, as is usually required for the process, affording the corresponding α-hydroxymethyl β-keto esters in high yields.

In(III) pyridinecarboxylate complexes: Composition, solution equilibria estimation, bioevaluation and interactions with HSA

Two In(III) – pyridinecarboxylates ([In(Pic)2(NO3)(H2O)] (InPic; HPic = picolinic acid), [In(HDpic)(Dpic)(H2O)2]·5H2O (InDpic; H2Dpic = dipicolinic acid), have been synthesized by one-step procedure. The complexes composition was confirmed by physicochemical analyses and X-ray diffraction confirmed molecular structure of both complexes. Moreover, complex species speciation was described in both systems by potentiometry and 1H NMR spectroscopy and mononuclear complex species were determined; [In(Pic)]2+ (logβ011 = 6.94(4)), [In(Pic)2]+ (logβ021 = 11.98(9)), [In(Dpic)]+ (logβ011 = 10.42(6)), [In(Dpic)2]− (logβ021 = 17.58(7)) and [In(Dpic)2(OH)]2− (logβ−121 = 10.18(6)). To confirm the complexes stability in 1 % DMSO, 1H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial and anticancer assays indicate a more significant sensitivity of S. aureus bacteria and MDA-MB-231 cancer cells to the InPic complex (IC50 = 25 and 340.7 μM) than to the InDpic (IC50 = 50 and 975.4 μM). The interaction and binding mechanism of picolinic/dipicolinic acid and their indium(III) complexes with HSA (human serum albumin) were studied using fluorescence and CD spectroscopy. The results confirmed that the studied compounds had bound successfully to HSA, and the binding parameters and constants (KSV, Kq, Kb) were calculated together with the number of binding sites. The binding forces were identified based on calculated thermodynamic parameters (ΔG, ΔH, ΔS). Synchronous spectra were used to study the microenvironment of Tyr and Trp residues and displacement assays revealed that site I was the preferred binding site. After binding, conformational changes were found to have occurred in the HSA molecule and the % α-helical content had decreased.

Development of a Rapid Fluorescence Probe for the Determination of Aqueous Hypochlorite

Chlorine interacts with aqueous environments, including the mucosa and alveolar fluid in the lungs, causing its the immediate transformation to hypochlorous acid (HClO) and hydrochloric acid (HCl) which induces cellular damage and may produce systemic toxicity. There are multiple techniques to monitor hypochlorite (HClO/ClO−) from various matrices, however, they each have significant disadvantages, including limited sensitivity, complexity, and slow response. In this study, we developed a water-soluble fluorescein-based probe, called fluorescein thioacid (FSH), for the rapid and sensitive detection of HClO/ClO− in aqueous solutions via oxidation of FSH to produce fluorescein. FSH was synthesized via a simple, one-step procedure and exhibited excellent selectivity for ClO−, maintaining 82% signal stability for 24 h. FSH performed well over a wide pH range (4–10; optimum pH of 4), produced a linear range from 1 to 100 µM, and had a detection limit of 100 nM. The probe was able to accurately quantify HClO/ClO− concentrations in tap water (13.8 μM) and swimming pool water (56.9 μM) samples. Overall, FSH is simple to synthesize, highly selective, highly sensitive, has excellent water solubility, and produces a fast response for monitoring of aqueous ClO− levels.

Three-Dimensionally Printed Biphasic Calcium Phosphate Ceramic Substrates as the Sole Inducer of Osteogenic Differentiation in Stromal Vascular Fraction Cells.

The stromal vascular fraction (SVF) is a derivate of fat tissue comprising both adipose-derived mesenchymal stem cells and endothelial cells and serves as a promising cell source for engineering vascularized bone tissues. Its combination with osteoconductive biphasic calcium phosphate (BCP) ceramic may represent a point-of-care agent for bone reconstruction. Here we assessed the proliferation and osteogenic differentiation capacities of SVF on 3D printed BCP implants, in comparison with isolated adipose-derived mesenchymal stem cells (AD-MSCs). AD-MSCs and SVF isolated from human donors were seeded on plastic or 3D printed BCP ceramics with sinusoidal or gyroid macrotopography and cultured in the presence or absence of osteogenic factors. Vascular, hematopoietic and MSC surface markers were assessed by flow cytometry whereas osteogenic activity was investigated through alizarin red staining and alkaline phosphatase activity. Osteogenic factors were necessary to trigger osteogenic activity when cells were cultured on plastic, without significant difference observed between the two cell populations. Interestingly, osteogenic activity was observed on BCP implants in the absence of differentiation factors, without significant difference in level activity between the two cell populations and macrotopography. This study offers supportive data for the use of combined BCP scaffolds with SVF in a perspective of a one-step surgical procedure for bone regeneration.

Effect of zinc oxide/graphene oxide nanocomposites on the cytotoxicity, antibacterial and mechanical properties of polymethyl methacrylate

BackgroundEnhancing the antibacterial properties of polymethyl methacrylate (PMMA) dental resins is crucial in preventing secondary infections following dental procedures. Despite the necessity for such improvement, a universally applicable method for augmenting the antibacterial properties of PMMA without compromising its mechanical properties and cytotoxicity remains elusive. Consequently, this study aims to address the aforementioned challenges by developing and implementing a composite material known as zinc oxide/graphene oxide (ZnO/GO) nanocomposites, to modify the PMMA.MethodsZnO/GO nanocomposites were successfully synthesized by a one-step procedure and fully characterized by TEM, EDS, FTIR and XRD. Then the physical and mechanical properties of PMMA modified by ZnO/GO nanocomposites were evaluated through water absorption and solubility test, contact angle test, three-point bending tests, and compression test. Furthermore, the biological properties of the modified PMMA were evaluated by direct microscopic colony count method, crystal violet staining and CCK-8.ResultsThe results revealed that ZnO/GO nanocomposites were successfully constructed. When the concentration of nanocomposites in PMMA was 0.2 wt. %, the flexural strength of the resin was increased by 23.4%, the compressive strength was increased by 31.1%, and the number of bacterial colonies was reduced by 60.33%. Meanwhile, It was found that the aging of the resin did not affect its antibacterial properties, and CCK-8 revealed that the modified PMMA had no cytotoxicity.ConclusionZnO/GO nanocomposites effectively improved the antibacterial properties of PMMA. Moreover, the mechanical properties of the resin were improved by adding ZnO/GO nanocomposites at a lower range of concentrations.

Design a WO3/Zn heterojunction for boosting the photodegradation of Favipiravir in aqueous solutions

ABSTRACT This study was aimed at designing a new type of heterojunction catalyst for the degradation of Favipiravir using visible light. Several WO3–ZnO nanocomposites with different Zn contents varying from 1 to 20 wt% were successfully developed via a simple one-step microwave irradiation procedure. Various analytical methods, including XRD, TEM, FESEM, EDAX, FTIR, and BET, BJH characterised the WO3-Zn catalysts. XRD pattern revealed that the small size of Zn ions is caused by the easy penetration of Zn ions into the WO3 crystalline with a monoclinic phase, which will lead to an increase in the surface area and a decrease in the size of the particles. According to FESEM and TEM images, nanocomposite particles had a non-uniform, irregular shape and a smaller particle size (20 to 40 nm). EDAX analysis related to WO3-Zn synthesised showed the O, W and Zn elements are 10%, 67%, and 23%, respectively. Response surface methodology using R software was used as a tool to optimise the amount of catalyst and Favipiravir concentration, time and pH. Effective parameters in the process, including the amount of catalyst in the range (0.5 to 2.5 g L−1), Favipiravir concentration in the range (1–10 mg L−1), time in the range (10–90 min) and pH in the range (4 to 9) were entered into the software and analysed. Under the optimised conditions of the parameters (pH, 4.96; amount of catalyst, 2 g L−1; amount of Favipiravir concentration, 10 mg L−1; and time, 60 min), the maximum removal efficiency (99.99%) was obtained. Also, 85.8% of the mineralisation of Favipiravir was found under the determined optimum conditions. Quenching experiments were conducted to investigate the reaction mechanism, the results showed that superoxide and hydroxyl oxidising radicals play an essential role in Favipiravir degradation..

Activation of Peroxymonosulfate by Fe, O Co-Embedded Biochar for the Degradation of Tetracycline: Performance and Mechanisms

In recent years, pollution stemming from pharmaceuticals has garnered widespread global concern, which exacerbates the ecological risk to both surface and groundwater. In the current study, Fe and O co-embedded biochar (Fe-O-BC) was synthesized through a one-step pyrolysis procedure with corncob serving as the feedstock. The fabricated Fe-O-BC catalysts were characterized by various techniques and were employed for the activation of peroxymonosulfate (PMS) to degrade tetracycline (TC). TC was rapidly degraded within 40 min, with a degradation rate of 0.1225 min−1, which was much higher than those for O-BC/PMS (0.0228 min−1) and Fe-BC/PMS (0.0271 min−1) under the same conditions. The effects of PMS dosage, Fe-O-BC dose, initial pH value and coexisting anions for TC degradation were investigated. Finally, the mechanism of TC oxidation in the catalytic system was implored through experiments of determining the active sites and radical scavenging experiments. The C-O-Fe bond in the catalyst was confirmed to be the dominant active sites accelerating TC degradation. Free diffused HO•, the surface-bound HO• and SO4•− and O2•−participated in the reaction and absorbed SO4•−, and HO• predominantly contributed to TC degradation. This study provides an efficient and green alternative for pharmaceutical wastewater treatment by Fe and O co-doped catalyst-induced heterogeneous process.

Pure 3D Conducting Polymer Network for an Ultra-Sensitive and Flexible Hydrogen Gas Sensor at Room Temperature

Hydrogen (H2) is considered a next-generation energy source with diverse applications across valuable social, economic, and industrial sectors, including transportation, biomedical, power generation, and space exploration. Due to its low ignition energy and wide flammable range, there is an urgent global demand for ultrasensitive, lightweight, portable, wearable, and flexible hydrogen sensors to identify early gas leaks and prevent environmental and economic implications.In this study, we present a flexible hydrogen gas sensor based on conducting polymers, namely polypyrrole (PPY) with graphene nanoparticles, synthesized by the bi-continuous microemulsion polymerization method. The one-step scalable synthetic procedure enables the design of 1D, 2D, and 3D conducting polymers and their nanocomposites with tunable morphological and electrical properties. The unique multilayered oil-to-water nature of the bi-continuous microemulsion allows the fabrication of pure mesoporous 3D conducting polymers and their composites without the addition of any cross-linkers with excellent electrical properties. The 3D pure porous polymer network acts as a monolithic conducting framework that facilitates electron and ion transport and promotes the diffusion of molecules and ions more efficiently than 1D or 2D structures. The soft and porous nature of the polymer improves the interaction and adsorption of the target gas molecules and sensing material by increasing the number of active sites.This 3D PPY_graphene flexible network synthesized by the bi-continuous microemulsion method is successfully utilized to fabricate an ultra-sensitive flexible gas sensor. The performance of the sensor can be modified based on the reactor design. The sensor exhibits a notable response to 1 ppm of H2 gas. At room temperature, the fabricated sensor displayed 14 and 20 seconds of response and recovery time, respectively. To the best of our knowledge, no study has explored the application of 3D pure conducting polymers and their nanocomposites for hydrogen gas sensors using the bi-continuous microemulsion polymerization method, yielding such exceptional sensing results. Figure 1

Two-step or one-step – are all methods for neonatal incubator decontamination equal?

Healthcare associated pathogens, including Staphylococcus capitis, can contaminate incubator surfaces and are of significant concern in neonatal intensive care units (NICUs). Effective incubator decontamination is essential for infection prevention and control, with submersion decontamination often recommended. This may not always be achievable, with wipe decontamination seen as an alternative. Here we compare the ability of a two-step (submersion in enzymatic detergent followed by wiping with hypochlorite-based wipes) with a one-step (wiping with quaternary ammonium compound-impregnated wipes) decontamination procedure to remove microbial surrogate markers from neonatal incubator surfaces. Three Cauliflower Mosaic Virus derived microbial surrogate markers were inoculated onto the fan, a mattress seam and the external arm port door clips of two Giraffe™ Omnibed™ Carestation™ incubators. Incubators were decontaminated either by the one-step or two-step decontamination process. Swab samples were collected from 28 sites on each incubator and surrounding environment, with marker presence determined by qPCR. Following two-step decontamination, 3/28 (11%) sample sites were positive for any marker, compared to 12/28 (43%) after one-step decontamination. Markers were transferred to several incubator surfaces and recovered from the originally inoculated sites following one-step decontamination, with the marker inoculated on door clips having the greatest transfer. Markers inoculated onto the mattress persisted through both decontamination strategies. Microbial surrogate markers were not completely removed from incubator surfaces by one-step decontamination alone. Two-step decontamination was the most effective method and removed markers from submergible surfaces, but not from the mattress. These findings indicate microorganisms can persist after incubator terminal decontamination, particularly on mattresses and when a two-step decontamination process is not used. This highlights the importance of effective decontamination practices to mitigate microorganism persistence on incubator surfaces.

Two-Step Conservative Surgery for Complicated Forms of Diabetes-Related Foot Osteomyelitis.

Diabetes-related foot osteomyelitis (DFO) is a common yet complex condition, often complicated by concurrent soft tissue infections (STIs). This study evaluates the efficacy of a two-step conservative surgical approach, hypothesizing that it offers comparable outcomes to a one-step procedure. Conducted on a cohort of 93 patients with DFO, the study categorized cases into two types: OM1 (osteomyelitis without STI) and OM2 (osteomyelitis with STI). OM2 was further subdivided into OM2a (early diagnosis) and OM2b (late diagnosis), with OM2 patients undergoing initial soft tissue debridement followed by elective bone surgery. The results indicated no significant differences in infection recurrence or amputation rates between the two surgical approaches, with recurrence observed in 20.7% of cases and amputations in 10.8%. The two-step procedure was associated with higher inflammatory responses and greater need for antibiotics and hospital admissions. However, these factors did not translate into increased recurrence or amputation compared to the one-step procedure. The study supports the two-step approach as a safe and effective method for managing complicated DFO cases, providing a viable alternative to immediate amputation or single-stage surgery. Despite some limitations, including regional specificity and potential underdiagnosis in late-diagnosed cases, the findings offer valuable insights for clinical management and suggest further research to refine treatment protocols. The study's strengths include confirmed histopathological diagnoses and consistent follow-up, reinforcing the validity of the two-step surgical approach for complex DFO treatment.

Aesthetic synthesis and comparative study of graphitic carbon nitride for energy storage applications

ABSTRACT Graphitic carbon nitride (gCN) has emerged as a suitable 2D material for various applications, such as photocatalysis, energy storage, and conversion. Due to their abundance of active sites, their unique layered structure, metal-free characteristics, high physicochemical stability, generous in nature, being environmentally friendly and having unique electrical characteristics. In this study, we use a one-step pyrolysis procedure to address these limitations and propose robust, low-cost, and scalable ways to synthesise materials. The synthesised gCN material graphitic phase is confirmed by X-ray diffraction analysis, the layered structure of the sp2 hybridised C-N bonding features is shown by FT-IR analysis. FESEM analyses provide insights into the morphology of gCN. Elemental identification and oxidation states were investigated using X-ray photoelectron spectroscopy (XPS). The electrochemical properties of gCN are performed using a two-electrode system with PVA/KOH electrolyte. The gCN nanostructure shows a specific capacitance of 183.20 F/g at a current density (CD) of 2 A/g, an energy density (ED) of 30.44 Wh/kg, and a power density (PD) of 2739.6 W/kg. Furthermore, the gCN nanostructure shows an excellent cycle life with 87.11% capacitance retention and 98.13% coulombic efficiency. These investigations clarify the electrochemical properties of gCN as an electrode material for supercapacitors.

A renewable screen-printed electrode based on magnetic NiCo@N-doped carbon nanotubes derived from Co-MOF for ractopamine detection.

A renewable electrochemical screen-printed electrode (SPE) is proposedbased on magnetic bamboo-like nitrogen-carbon (N-C) nanotubes loaded with nickel-cobalt alloy (NiCo) nanoparticles (NiCo@N-CNTs) for the determination of ractopamine (RAC). During the preparation of NiCo@N-CNTs, Co-MOF-67 (ZIF-67) was firstly synthesized, and then blended with dicyandiamide and nickel acetate, followed by a one-step pyrolysis procedure to prepare NiCo@N-doped carbon nanotubes. The surface morphology, structure, and chemical composition of NiCo@N-CNTs were characterized by SEM, TEM, XRD, XPS, and EDS. The electrocatalytic and electrochemical behavior of NiCo@N-CNTs were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results demonstrated that NiCo@N-CNTs possessed remarkable conductivity and electrocatalysis to the oxidation of ractopamine (RAC). By using screen-printed electrode (SPE), NiCo@N-CNTs, and a designed base support, a magnetic RAC sensor (NiCo@N-CNTs/SPE) was successfully constructed. It presented a detection linear range of 0.05-80μM with a detection limit of 12nM (S/N = 3). It also exhibited good sensitivity, reproducibility, and practicability in spiked real pork samples. Since the adhesion of NiCo/N-CNTs on SPE was controlled by magnet, the NiCo@N-CNTs was easily detached from theSPE surface by magnetism and thus displayed excellent renewability. This work broadened insights into portable devices for on-site and real-time analysis.

Periodic spinodal decomposition in double–strengthened medium–entropy alloy

Achieving an optimal balance between strength and ductility in advanced engineering materials has long been a challenge for researchers. In the field of material strengthening, most approaches that prevent or impede the motion of dislocations involve ductility reduction. In the present study, we propose a strengthening approach based on spinodal decomposition in which Cu and Al are introduced into a ferrous medium–entropy alloy. The matrix undergoes nanoscale periodic spinodal decomposition via a simple one-step aging procedure. Chemical fluctuations within periodic spinodal decomposed structures induce spinodal hardening, leading to a doubled strengthening effect that surpasses the conventional precipitation strengthening mechanism. Notably, the periodic spinodal decomposed structures effectively overcome strain localization issues, preserving elongation and doubling their mechanical strength. Spinodal decomposition offers high versatility because it can be implemented with minimal elemental addition, making it a promising candidate for enhancing the mechanical properties of various alloy systems.

Urea Biosensing through Integration of Urease to the PEDOT-Polyamine Conducting Channels of Organic Electrochemical Transistors: pH-Change-Based Mechanism and Urine Sensing

We present the construction of an organic electrochemical transistor (OECT) based on poly(3,4-ethylendioxythiophene, PEDOT) and polyallylamine (PAH) and its evaluation as a bioelectronic platform for urease integration and urea sensing. The OECT channel was fabricated in a one-step procedure using chemical polymerization. Then, urease was immobilized on the surface by electrostatic interaction of the negatively charged enzyme at neutral pH with the positively charged surface of PEDOH-PAH channels. The real-time monitoring of the urease adsorption process was achieved by registering the changes on the drain–source current of the OECT upon continuous scan of the gate potential during enzyme deposition with high sensitivity. On the other hand, integrating urease enabled urea sensing through the transistor response changes resulting from local pH variation as a consequence of enzymatic catalysis. The response of direct enzyme adsorption is compared with layer-by-layer integration using polyethylenimine. Integrating a polyelectrolyte over the adsorbed enzyme resulted in a more stable response, allowing for the sensing of urine even from diluted urine samples. These results demonstrate the potential of integrating enzymes into the active channels of OECTs for the development of biosensors based on local pH changes.

Oat-seed-like W18O49 mesocrystals for highly sensitive low-temperature NO2 sensing application

Oat-seed-like W18O49 (OSL_W18O49) mesocrystals were synthesized through hydrothermal method based on a facile one-step procedure. The microstructure characterization based on SEM and TEM (scanning electron microscope and transmission electron microscope) shows the self-assembled nanowires for the formation of as-prepared oat-seed-like W18O49 nanomaterials. Gas sensing measurements indicate that the oat-seed-like W18O49 based sensor exhibits good response (2.6 and 9.6 toward 1 ppm NO2 at 25 °C and 90 °C, respectively) with excellent gas selectivity, rapid response speed and fast recovery time. Owing to the enhanced excellent performance, our results demonstrate the application potential of oat-seed-like W18O49 for NO2 detecting at low temperature. This work opens an easy pathway for facile preparation of mesocrystal W18O49 and it is a novel strategy to design gas-sensing materials for sensing volatile organic compounds with high performance.

Synthesis of green nanosorbent from bovine serum albumin and curcumin for magnetic solid phase extraction of pesticides from food samples

For the first time, a magnetic carbon nanocomposite was synthesized using one-step hydrothermal procedure, employing bovine serum albumin, curcumin, and ferric ammonium citrate. Additionally, the application of this novel composite as an adsorbent for magnetic dispersive solid phase extraction of fungicides and pesticides from water and food samples is a unique aspect of this study. Under optimum conditions (salt concentration: 5.0% w/v, pH: 7.0, desorption solvent: ethanol, sorbent amount: 20 mg, extraction time: 20 min, desorption time: 3 min, stirring rate: 500 rpm, sample volume: 30 mL, extraction temperature: room temperature, and desorption solvent volume: 150 μL) linearity (2.5 to 1400 ng mL−1), coefficients of determination (R2 ≥ 0.997), limits of detection (0.75 to 1.5 ng mL−1), and limits of quantification (2.5 to 5.0 ng mL−1) were achieved. The method validation results showed extraction recovery ranging from 71.2% to 93.4%, and preconcentration factors ranging from 142.5 to 186.1.