Enhancing the sustainable immobilization of laccase by amino-functionalized PMMA-reinforced graphene nanomaterial.

Human health and the environment are negatively affected by endocrine-disrupting chemicals (EDCs), such as bisphenol A. Therefore, developing appropriate remediation methods is essential for efficiently removing phenolic compounds from aqueous solutions. Enzymatic biodegradation is a potential biotechnological approach for responsibly addressing water pollution. With its high catalytic efficiency and few by-products, laccase is an eco-friendly biocatalyst with significant promise for biodegradation. Herein, two novel supporting materials (NH2-PMMA and NH2-PMMA-Gr) were fabricated via the functionalization of poly(methylmethacrylate) (PMMA) polymer using ethylenediamine and reinforced with graphene followed by glutaraldehyde activation. NH2-PMMA and NH2-PMMA-Gr were utilized for laccase immobilization with an immobilization yield (IY%) of 78.3% and 82.5% and an activity yield (AY%) of 81.2% and 85.9%, respectively. Scanning electron microscope (SEM) and Fourier-transform infrared (FTIR) were used to study the characteristics of fabricated material supports. NH2-PMMA-Gr@laccase exhibited an optimal pH profile from 4.5 to 5.0, while NH2-PMMA@laccase exhibited optimum pH at 5.0 compared to a value of 4.0 for free form. A wider temperature ranges of 40-50 °C was noted for both immobilized laccases compared to a value of 40 °C for the free form. Additionally, it was reported that immobilized laccase outperformed free laccase in terms of substrate affinity and storage stability. NH2-PMMA@laccase and NH2-PMMA-Gr@laccase improved stability by up to 3.9 and 4.6-fold when stored for 30 days at 4 °C and preserved up to 80.5% and 86.7% of relative activity after ten cycles of reuse. Finally, the degradation of BPA was achieved using NH2-PMMA@laccase and NH2-PMMA-Gr@laccase. After five cycles, NH2-PMMA@laccase and NH2-PMMA-Gr@laccase showed that the residual degradation of BPA was 77% and 84.5% using 50 µm of BPA. This study introduces a novel, high-performance material for organic pollution remediation in wastewater that would inspire further progress.

Sustainable Immobilization of ß-Glucosidase onto Silver Ions and AgNPs-Loaded Acrylic Fabric with Enhanced Stability and Reusability.

Modified polymer design has attracted significant attention for enzyme immobilization, offering promising applications. In this study, amine-terminated polymers were synthesized by incorporating functional groups into polyacrylonitrile using hexamethylenediamine. This work highlights the successful enzyme immobilization strategy using modified polymers, offering improved stability and expanded operational conditions for potential biotechnological applications. The resulting amino groups were utilized to capture silver ions, which were subsequently converted to silver nanoparticles (AgNPs). The obtained materials, AgNPs@TA-HMDA (acrylic textiles coated silver nanoparticles AgNPs) and Ag(I)@TA-HMDA (acrylic textiles coated with Ag ion) were employed as supports for ß-glucosidase enzyme immobilization. The highest immobilization yields (IY%) were achieved with AgNPs@TA-HMDA at 92%, followed by Ag(I)@TA-HMDA at 79.8%, resulting in activity yields (AY%) of 81% and 73%, respectively. Characterization techniques such as FTIR, FE-SEM, EDX, TG/DTG, DSC, and zeta potential were employed to investigate the structural composition, surface morphologies, elemental composition, thermal properties, and surface charge of the support materials. After 15 reuses, the preservation percentages decreased to 76% for AgNPs@TA-HMDA/ß-Glu and 65% for Ag(I)@TA-HMDA/ß-Glu. Storage stability revealed that the decrease in activity for the immobilized enzymes was smaller than the free enzyme. The optimal pH for the immobilized enzymes was broader (pH 5.5 to 6.5) compared to the free enzyme (pH 5.0), and the optimal temperature for the immobilized enzymes was 60 °C, slightly higher than the free enzyme's optimal temperature of 50 °C. The kinetic analysis showed a slight increase in Michaelis constant (Km) values for the immobilized enzymes and a decrease in maximum velocity (Vmax), turnover number (Kcat), and specificity constant (Kcat/Km) values compared to the free enzyme. Through extensive characterization, we gained valuable insights into the structural composition and properties of the modified polymer supports. This research significantly contributes to the development of efficient biotechnological processes by advancing the field of enzyme immobilization and offering valuable knowledge for its potential applications.

Synthesis and characterization of phenothiazine sensor for spectrophotometric and fluorescence detection of cyanide.

A sensitive and selective phenothiazine-based sensor (PTZ) has been successfully synthesized. The sensor PTZ displayed specific identification of CN- 'turn-off' fluorescence responses with a quick reaction and strong reversibility in an acetonitrile:water (90:10, V/V) solution. The sensor PTZ for detecting CN- exhibits the marked advantages of quenching the fluorescence intensity, fast response time (60 s), and low value of the detection limit. The concentration that is authorized for drinking water by the WHO (1.9 µM) is far higher than the detection limit, which was found to be 9.11 × 10-9 . The sensor displays distinct colorimetric and spectrofluorometric detection for CN- anion due to the addition of CN- anion to the electron-deficient vinyl group of PTZ, which reduces intramolecular charge transfer efficiencies. The 1:2 binding mechanism of PTZ with CN- was validated by fluorescence titration, Job's plot, HRMS, 1 H NMR, FTIR analysis, and density functional theory (DFT) investigations, among other methods. Additionally, the PTZ sensor was successfully used to precisely and accurately detect cyanide anions in actual water samples.

Novel and Facile Colorimetric Detection of Reducing Sugars in Foods via In Situ Formed Gelatin-Capped Silver Nanoparticles.

The evolution of green technology for the simple and ecological formation of silver nanoparticles (AgNPs) inspired the present work for simple and efficient detection of reducing sugars (RS) in foods. The proposed method relies on gelatin as the capping and stabilizing agent and the analyte (RS) as the reducing agent. This work may attract significant attention, especially in the industry, for testing the sugar content using gelatin-capped silver nanoparticles as it not only detects the sugar in food, but also determines the content (%), which could be an alternative technique to the conventionally used DNS colorimetric method. For this purpose, a certain amount of maltose was mixed with a gelatin-silver nitrate. Different conditions that may affect the color changes at 434 nm owing to the in situ formed AgNPs, such as gelatin-silver nitrate ratio, PH, time, and temperature, have been investigated. The 1:3 mg/mg ratio of gelatin-silver nitrate dissolved in 10 mL distilled water was most effective in color formation. The development of AgNPs color increases within 8-10 min at PH 8.5 as the selected optimum value and at the optimum temperature of 90 °C for the evolution of the gelatin-silver reagent's redox reaction. The gelatin-silver reagent showed a fast response (less than 10 min) with a detection limit for maltose at 46.67 µM. In addition, the selectivity of maltose was checked in the presence of starch and after its hydrolysis with α-amylase. Compared with the conventionally used dinitrosalicylic acid (DNS) colorimetric method, the proposed method could be applied to commercial fresh apple juice, watermelon, and honey to prove its viability for detecting RS in fruits; the total reducing sugar content was 287, 165, and 751 mg/g, respectively.

The Impact of TPA Auxiliary Donor and the π-Linkers on the Performance of Newly Designed Dye-Sensitized Solar Cells: Computational Investigation.

The efficiency of the newly designed dye-sensitized solar cells (DSSCs) containing triphenylamine, diphenylamine (TPA), phenothiazine, and phenoxazine as donors and triazine, phenyl with D1-D2-π-linker-π-(A)2 architecture has been investigated using density functional theory (DFT) and time-dependent (TD-DFT) methods. These methods were used to investigate the geometrical structures, electronic properties, absorption, photovoltaic properties, and chemical reactivity. Furthermore, the calculated results indicate that different architectures can modify the energy levels of HOMO and LUMO and reduce the energy gap. The absorption undergoes a redshift displacement. This work aims at calculating the structural geometries and the electronic and optical properties of the designed dyes. Furthermore, the dye adsorption characteristics, such as the optoelectronic properties and the adsorption energies in the TiO2 clusters, were calculated with counterpoise correction and discussed.

Acrylic fabric and nanomaterials to enhance α-amylase-based biocatalytic immobilized systems for industrial food applications.

An innovative approach for immobilizing α-amylase was used in this investigation. The acrylic fabric was first treated with hexamethylene diamine (HMDA) and then coated with copper ions that were later reduced to copper nanoparticles (CuNPs). The corresponding materials obtained, Cu(II)@HMDA-TA and CuNPs@HMDA-TA, were employed as carriers for α-amylase, respectively. The structural and morphological characteristics of the produced support matrices before and after immobilization were assessed using various techniques, including FTIR, SEM, EDX, TG/DTG, DSC, and zeta potential. The immobilized α-amylase exhibited the highest level of activity at pH 7.0, with immobilization yields observed for CuNPs@HMDA-TA (81.7 %) (60 unit/g support) followed by Cu(II)@HMDA-TA (71.7 %) (49 unit/g support) and 75 % and 61 % of activity yields, and 91.7 % and 85 % of immobilization efficiency, respectively. Meanwhile, biochemical characterizations of the activity of the soluble and immobilized enzymes were carried out and compared. Optimal temperature, pH, kinetics, storage stability, and reusability parameters were optimized for immobilized enzyme activity. The optimal pH and temperature were recorded as 6.0 and 50 °C for soluble α-amylase while the two forms of immobilized α-amylase exhibit a broad pH of 6.0-7.0 and optimal temperature at 60 °C. After recycling 15 times, the immobilized α-amylase on CuNPs@HMDA-TA and Cu(II)@HMDA-TA preserved 63 % and 52 % of their activities, respectively. The two forms of immobilized α-amylase displayed high stability when stored for 6 weeks and preserved 85 % and 76 % of their activities, respectively. Km values were calculated as 1.22, 1.39, and 1.84 mg/mL for soluble, immobilized enzymes on CuNPs@HMDA-TA, and Cu(II)@HMDA-TA, and Vmax values were calculated as 36.25, 29.68, and 21.57 µmol/mL/min, respectively. The total phenolic contents of maize kernels improved 1.4 ± 0.01 fold after treatment by two immobilized α-amylases.

Synthesis and Characterization of Aminoamidine-Based Polyacrylonitrile Fibers for Lipase Immobilization with Effective Reusability and Storage Stability.

Lipases are extensively utilized industrial biocatalysts that play an important role in various industrial and biotechnological applications. Herein, polyacrylonitrile (PAN) was treated with hexamethylene diamine (HMDA) and activated by glutaraldehyde, then utilized as a carrier support for Candida rugosa lipase. In this regard, the morphological structure of modified PAN before and after the immobilization process was evaluated using FTIR and SEM analyses. The immobilized lipase exhibited the highest activity at pH 8.0, with an immobilization yield of 81% and an activity of 91%. The optimal pH and temperature for free lipase were 7.5 and 40 °C, while the immobilized lipase exhibited its optimal activity at a pH of 8.0 and a temperature of 50 °C. After recycling 10 times, the immobilized lipase maintained 76% of its activity and, after 15 reuses, it preserved 61% of its activity. The lipase stability was significantly improved after immobilization, as it maintained 76% of its initial activity after 60 days of storage. The calculated Km values were 4.07 and 6.16 mM for free and immobilized lipase, and the Vmax values were 74 and 77 µmol/mL/min, respectively. These results demonstrated that synthetically modified PAN is appropriate for immobilizing enzymes and has the potential for commercial applications.

Characterization of graphene oxide-ziziphus seeds and its application as a hazardous dye removal adsorbent.

The zizphus seeds are considered as a biomaterial residues that has been used for removing of organic industrial waste such as 2-((10-octyl-9,10-dihydroanthracene-2-yl) methylene) malononitrile (PTZS-CN) dye from aqueous solutions utilizing graphene oxide-Ziziphus (GO-Ziziphus). A batch study explored the impacts of various experimental circumstances, including solution pH, initial dye concentration, temperature, and contact time. General order, nonlinear pseudo-first order and pseudo-second order, elvoich model and intraparticiple diffusion were utilized to analyze the kinetic data. The adsorption kinetics of dye onto GO-ziziphus adsorption was best mentioned by nonlinear pseudo-first order. Similarly, the intra-particle diffusion plots revealed one exponential line throughout the adsorption process. The Freundlich, Dubinin-Radushkevich, and Langmuir models were employed to examine isothermal data. It provided the best fit of the dye adsorption isothermal data onto GO-ziziphus Freundlich models. Besides, the calculated free energies showed that the adsorption progression was physical adsorption. Thermodynamic calculations revealed that dye adsorption onto GO-ziziphus was exothermic and spontaneous. The combined results indicated that GO-ziziphus powder might be used to treat dye-rich wastewater effectively.

Eco-friendly salt/alkali-free exhaustion dyeing of cotton fabric with reactive dyes.

The textile-wet process enormously consumes a large volume of water and chemicals, and thus awareness of cleaner production has been growing to protect the environment from the industrial effluents. In this context, reactive dyeing of cellulosic materials such as cotton fabrics is a major sector of textile coloration that necessitates the use of a large amount of sodium sulfate or sodium chloride and alkali to exhaust and fix the dye molecules with cellulosic macromolecules, respectively. However, the remaining salt and alkali in the effluent badly affect the environment. For this purpose, the use of trisodium nitrilotriacetate (TNA) in reactive dyeing of cotton fabrics was hypothesized to have a double benefit, one as an exhausting agent (organic salt) and the second as a fixing agent (organic base). Thus, the exhaust dyeing characteristics of cotton fabrics using C.I. Reactive Yellow 145 (RY145) was optimized under different conditions of TNA concentration, alkali concentration, temperature, and dyeing time. The color strength and the primary and secondary exhaustion values were also investigated with an eye on those values obtained using the conventional dyeing method. The characterization of effluent samples with RY 145 taken after dyeing using TNA compared with conventional dyeing indicated an efficient reduction of COD, BOD, and TDS values by 99, 97, and 97%, respectively. The new dyeing method was implemented using C.I. Reactive Black 5 (RB5), C.I. Reactive Blue 160 (RB160), and C.I. Reactive Red 24 (RR24) to reveal good dyeability and fastness properties comparable with those obtained using the conventional method. The overall results obtained suggest the suitability of TNA as an environmentally friendly agent suitable as an exhausting and fixing agent of cellulosic fabrics.

Characterization of Date Seed Powder Derived Porous Graphene Oxide and Its Application as an Environmental Functional Material to Remove Dye from Aqueous Solutions.

This study aims to prepare graphene oxide (GO) from raw date seeds (RDSs), considered one of the available agricultural wastes in Saudi Arabia. The preparation method is done by the conversion of date seeds to lignin and then to graphite which is used in a modified Hummer's method to obtain GO. The adsorption of insoluble phenothiazine-derived dye (PTZS) over raw date Seeds (RDSs) as a low-cost adsorbent was investigated in this study. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR) were used to characterize (RDSs). According to the calculations, Freundlich isotherms and pseudo-second-order accurately predicted the kinetic rate of adsorption. The adsorption ability was 4.889 mg/g, and the removal rate was 93.98% GO-date Seeds mass, 11 mg/L starting dye concentration, at a temperature of 328 K, pH 9, and contact length of 30 min by boosting the PTZS solution's ionic strength. In addition, the computed free energies revealed that the adsorption process was physical. Thermodynamic calculations revealed that dye adsorption onto GO-date seeds was exothermic and spontaneous.

In Situ Coating of Polydopamine-AgNPs on Polyester Fabrics Producing Antibacterial and Antioxidant Properties.

Nanoparticles are increasingly utilized as coating materials to improve the properties of polyester textiles. In this work, polyester textiles were successfully fabricated, with hydrazide groups serving as ligands for the entrapment of sliver ions and subsequent reduction to AgNPs. Polydopamine (PDA) was used in this work to impart antibacterial and antioxidant properties to the polyester textiles through its phenolic hydroxyl groups, which can convert silver ions into AgNPs. Moreover, glucose was used as a reducing agent to create AgNPs-loaded polyester hydrazide. ATR-FTIR, SEM, EDX, thermogravimetric analysis (TGA), and tensile strength were used to characterize the pristine polyester, the polyester hydrazide, the PDA-coated AgNP-loaded polyester hydrazide and the AgNP-loaded polyester hydrazide. A broth test was also used to investigate the textile's antimicrobial activities against Escherichia coli and Staphylococcus aureus. Overall, the composite nanocoating with PDA-AgNPs demonstrated good tensile strength and antioxidant and antibacterial characteristics, implying the practicality of PDA-AgNPs coating polyester for biomedical textile applications.

Green Synthesis and Antibacterial Activity of Ag/Fe2O3 Nanocomposite Using Buddleja lindleyana Extract.

In the study reported in this manuscript, silver/iron oxide nanocomposites (Ag/Fe2O3) were phytosynthesized using the extract of Buddleja lindleyana via a green, economical and eco-friendly strategy. The biosynthesized Ag/Fe2O3 nanocomposites were characterized using UV-Vis spectrophotometry, FTIR, XRD, TEM, DLS and SEM-EDX analyses. The particulates showed a triangular and spherical morphology having sizes between 25 and 174 nm. FTIR studies on the nanoparticles showed functional groups corresponding to organic metabolites, which reduce and stabilize the Ag/Fe2O3 nanocomposite. The antimicrobial efficacy of the phytosynthesized Ag/Fe2O3 against bacterial pathogens was assessed. In addition, Ag/Fe2O3 exhibited broad spectrum activities against B. subtilis, S. aureus, E. coli, and P. aeruginosa with inhibition zones of 23.4 ± 0.75, 22.3 ± 0.57, 20.8 ± 1.6, and 19.5 ± 0.5 mm, respectively. The Ag/Fe2O3 composites obtained showed promising antibacterial action against human bacterial pathogens (S. aureus, E. coli, B. subtilis and P. aeruginosa), making them candidates for medical applications.

Facile Synthesis and Characterization of CeO2-Nanoparticle-Loaded Carboxymethyl Cellulose as Efficient Protective Films for Mild Steel: A Comparative Study of Experiential and Computational Findings.

Corrosion is considered to be the most severe problem facing alloys and metals, one that causes potentially dangerous industrial issues such as the deterioration of buildings and machinery, and corrosion in factory tanks and pipelines in petroleum refineries, leading to limited lifetime and weak efficacy of such systems. In this work, novel CeO2-nanoparticle-loaded carboxymethyl cellulose (CMC) was successfully prepared by using a simple method. The structural configuration of the prepared CeO2-nanoparticle-loaded CMC was investigated by FE-SEM/EDX, TEM, FT-IR, and thermal analyses. The corrosion protection proficiency of uncoated and coated mild steel with CeO2-CMC systems in 1.0 M HCl solutions was studied by EOCP-time, EIS, and PDP tools. Moreover, the relationship between the structure of coating films and their corrosion protection was confirmed by DFT calculation and MC simulation. The obtained findings from the studied methods showed that the prepared CeO2-CMC-coated films reported high corrosion resistance. The protection capacity augmented with ceria presents an increase of up to 3% to achieve 98.4%. DFT calculation and MC simulation confirmed the influence of the chemical construction of coated films on its protection capacity, which was in accordance with the experimental results.

Experimental and In-Silico Computational Modeling of Cerium Oxide Nanoparticles Functionalized by Gelatin as an Eco-Friendly Anti-Corrosion Barrier on X60 Steel Alloys in Acidic Environments.

An eco-friendly and a facile route successfully prepared novel cerium oxide nanoparticles functionalized by gelatin. The introduced CeO2@gelatin was investigated in terms of FE-SEM, EDX, TEM, chemical mapping, FT-IR, and (TGA) thermal analyses. These characterization tools indicate the successful synthesis of a material having CeO2 and gelatin as a composite material. The prepared composite CeO2@gelatin was used as an environment-friendly coated film or X60 steel alloys in acidizing oil well medium. Moreover, the effect of CeO2 percent on film composition was investigated. LPR corrosion rate, Eocp-time, EIS, and PDP tools determined the corrosion protection capacity. The CeO2@gelatin composite exhibited high protection capacity compared to pure gelatin; in particular, 5.0% CeO2@gelatin coating film shows the highest protection capacity (98.2%), with long-term anti-corrosive features. The % CeO2@gelatin-coated films formed the protective adsorbed layer on the steel interface by developing a strong bond among nitrogen atoms in the CeO2@gelatin film and the electrode interface. Surface morphology using FESEM measurements confirmed the high efficiency of the fabricated CeO2@gelatin composite on the protection X60 steel alloys. DFT calculations and MC simulations were explored to study the relations between the protection action and the molecular construction of the coated systems, which were in good alignment with the empirical findings.

AIE and reversible mechanofluorochromism characteristics of new imidazole-based donor-π-acceptor dyes.

Four new imidazole-based donor-π-acceptor 2a-2d dyes have been synthesized, and their solvatochromism, aggregation-induced emission (AIE) and mechanofluorochromic (MFC) properties were investigated. The new dyes 2a-2d were designed to have 1,4,5-triphenyl-1H-imidazole as an electron donor (D) and 1-indanone, 1,3-indandione, 2-phenylacetonitrile and 2-thiopheneacetonitrile as electron acceptors (A) linked through a phenyl bridge. The maximum absorption wavelength of 2a-2d dyes in DCM solution appeared at 376, 437, 368, and 375 nm, respectively. The dyes exhibit a high molar extinction coefficient (ε) and large Stokes shift, making them useful in optoelectronic applications. Solvatochromic properties of dyes 2a-2d have been studied and showed bathochromic changes in emission wavelengths, from 449 to 550 nm for 2a, 476 to 599 nm for 2b, 438 to 520 nm for 2c, and from 439 to 529 nm for 2d, as the solvent polarity increased from n-hexane to acetonitrile. Moreover, in dioxane/water mixture systems, AIE behaviors were observed, and the emission intensity of 2b-2d dyes increased by around 5, 3, and 3 times in the mixed solvent (dioxane : water = 10 : 90) in contrast to pure dioxane. In addition, the XRD data of the 2a-2d dyes in pristine, ground, and fumed states illustrate that the transition between the ordered crystalline and disordered amorphous phases is the primary cause of MFC behaviors mechanism. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) showed that the highest occupied molecular orbital (HOMO) of dyes is distributed on the donor unit. In contrast, the lowest unoccupied molecular orbital (LUMO) is mainly placed on the acceptor unit to reveal that the HOMO-LUMO transition has a great ICT character.

Photovoltaic performance and power conversion efficiency prediction of double fence porphyrins.

To explore high efficiency dye-sensitized solar cells (DSSCs), two experimentally derived (single fence and double fence porphyrins) and two theoretically designed zinc porphyrin molecules with D-D-π-A-A configurations were studied. Density functional theory and time-dependent density functional theory were employed to simulate these two experimental dyes and dye@TiO2 systems to understand why the double fence porphyrin molecule exhibits better photovoltaic performance than the single fence porphyrin molecule. For the short-circuit current (JSC), the various parameters that affected the experimental magnitude of JSC were analyzed from different aspects of absorption, charge transfer and chemical parameters as well as an electron injection process. The almost equal open-circuit voltages (VOC) in the experiment were predicted by theoretical VOC calculations. Our model predicted power conversion efficiencies (PCEs) of 1.993% and 10.866% for the single and double fence molecules, respectively, which are in accordance with the experimental values of 3.48% and 10.69%, respectively. In addition, one designed two new molecules based on the double fence porphyrin molecule with a 2-methyl-2H-benzo[d][1,2,3]triazole (BTA) unit bearing one fluorine and two fluorine atoms as the guest acceptor, respectively. Compared to the original molecules, the engineered molecules significantly improved the photovoltaic parameters, JSC and VOC, thereby causing excellent PCEs. The most outstanding designed molecule reached a PCE of 12.155%, and is considered a candidate dye for high-efficiency DSSC. This study provides insights into the photoelectric properties of single and double fence porphyrins. It also demonstrated that the strong electron-withdrawing ability of fluorine atoms would enhance the photovoltaic performance and provide a guideline for the further design of double fence porphyrins.

Novel Triarylamine-Based Hole Transport Materials: Synthesis, Characterization and Computational Investigation.

Three novel triarylamine-based electron-rich chromophores were synthesized and fully characterized. Compounds 1 and 2 were designed with electron-rich triphenylamine skeleton bearing two and four decyloxy groups namely, 3,4-bis(decyloxy)-N,N-diphenylaniline and N-(3,4-bis(decyloxy)phenyl)-3,4-bis(decyloxy)-N-phenylaniline, respectively. The well-known electron-rich phenothiazine was introduced to diphenylamine moiety through a thiazole ring to form N,N-bis(3,4-bis(decyloxy)phenyl)-5-(10H-phenothiazin-2-yl)thiazol-2-amine (Compound 3). These three novel compounds were fully characterized and their UV-vis absorption indicated their transparency as a favorable property for hole transport materials (HTMs) suitable for perovskite solar cells. Cyclic voltammetry measurements revealed that the HOMO energy levels were in the range 5.00-5.16 eV for all compounds, indicating their suitability with the HOMO energy level of the perovskite photosensitizer. Density functional theory (DFT) and time-dependent DFT (TD-DFT) have been used to investigate the possibility of the synthesized compounds to be utilized as HTMs for perovskite solar cells (PSCs). The computational investigation revealed that the hole mobility of Compound 1 was 1.08 × 10-2 cm2 V-1 s-1, and the substitution with two additional dialkoxy groups on the second phenyl ring as represented by Compound 2 significantly boosted the hole mobility to reach the value 4.21 × 10-2 cm2 V-1 s-1. On the other hand, Compound 3, in which the third phenyl group was replaced by a thiazole-based phenothiazine, the value of hole mobility decreased to reach 5.93 × 10-5 cm2 V-1 s-1. The overall results indicate that these three novel compounds could be promising HTMs for perovskite solar cells.

Hydroxyapatite-decorated ZrO2 for α-amylase immobilization: Toward the enhancement of enzyme stability and reusability.

Herein, the immobilization of α-amylase onto hydroxyapatite (HA) and hydroxyapatite-decorated ZrO2 (10%wt) (HA-ZrO2) nanocomposite were investigated. The immobilization yield was 69.7% and 84% respectively. The structural differences were characterized using X-Ray diffraction, attenuated total reflectance-Fourier transform infrared spectra, Raman, and scanning electron microscope. After 10 repeated cycles, the residual activity of immobilized α-amylase onto HA and HA-ZrO2 nanocomposite was 46% and 70%, respectively. The storage stability was recorded to be 27%, 50% and 69% from its initial activity in the case of free and immobilized enzyme onto HA and HA-ZrO2 nanocomposite, respectively after 8 weeks. The pH-activity profile and temperature revealed pH 6.0 and temperature 50 °C as the optimal values of free α-amylase, while the optimum values for α-amylase on HA and HA-ZrO2 was shifted to pH 6.5 and 60 °C after immobilization. The immobilized α-amylase onto HA-ZrO2 showed comparatively higher catalytic activity than the free α-amylase. The Km value after the immobilization process onto HA was 2.1 folds highly than that of the free enzyme. In conclusion, it can be inferred that HA-ZrO2 is more sustainable and beneficial support for enzyme immobilization and it represents promising supports for different uses of α-amylase in the biomedical applications.

Synthesis of Novel Chalcone-Based Phenothiazine Derivatives as Antioxidant and Anticancer Agents.

Based on reported results for the potential medicinal impact of phenothiazine core, as well as the chalcone skeleton that is widely present in many natural products, together with their reported bioactivities, the present work was aimed at combining both moieties in one molecular skeleton and to synthesize and characterize a novel series of chalone-based phenothiazine derivatives. For this purpose, 2-acetylphenothiazine was N-alkylated, followed by the Claisen-Schmidt reaction to produce the chalcones with good yield. Antioxidant activity, as evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, was assessed to determine if their antioxidant potential was comparable with ascorbic acid, and attributable to the phenothiazine core. Screening anticancer activities of the synthesized chalone-based phenothiazine derivatives against human breast cancer cell line MCF-7 cells, and human hepatocellular carcinoma HepG-2 cells, compared with standard drugs cisplatin and doxorubicin, was evaluated. The results revealed that compounds 4a, 4b, 4d, 4h, 4j, 4k, 4m, 4o, and 4p were good against human hepatocellular carcinoma HepG-2 cells, and among these compounds 4b and 4k were the most effective compounds, with IC50 values of 7.14 µg/mL and 7.6 1 µg/mL, respectively. On the other hand, compounds 4a, 4b, 4k, and 4m were good against human breast cancer cell line MCF-7 cells and, among these compounds, 4k and 4b were the most effective compounds, with IC50 values of 12 µg/mL and 13. 8 µg/mL, respectively. The overall results suggest that these compounds could, potentially, be further modified for the formation of more potent antioxidant and anticancer agents.

Nanoporous colorant sensors and captors for simultaneous recognition and recovery of gold from E-wastes.

Platinum group metals have gained significant interest due to their unique characteristics, which make them the main constituents in advanced applications. In this work, we introduce new pH-dependent optical mesocaptors for the colorimetric monitoring and separation of Au(III) from E-waste leach liquors without a preconcentration process. The mesoporous silica nanospheres are fabricated via simple, reproducible, and low-cost procedures. The optical mesocaptor is designed via indirect immobilization of thiazole yellow G (TYG) and amacid yellow M (AYM) chromogenic probes onto mesoporous nanostructured scaffolds. The silanol groups in the mesopores of silica surface robustly anchored dilauryl dimethyl ammonium bromide (DDAB) linker to induce the interactions with the TYG and AYM chelates, thereby leading to the fashioning of a stable optical mesocaptors without releasing of the chelates throughout adsorption and sensing assays. The finding provides evidence of the capability of the synthesized decorated new nanostructured sensor shows excellent sensitivity toward Au(III) with a limit of detection (LOD) as low as 1.16 µg L-1. Furthermore, the new sensors were able to selectively detect Au(III) in solution with multi ions components.