Selective and sensitive CQD-based sensing platform for Cu2+ detection in Wilson's disease.

Excessive Cu2+ intake can cause neurological disorders (e.g. Wilson's disease) and adversely affect the gastrointestinal, liver, and kidney organs. The presence of Cu2+ is strongly linked to the emergence and progression of Wilson's disease (WD), and accurately measuring the amount of copper is a crucial step in diagnosing WD at an early stage in a clinical setting. In this work, CQDs were fabricated through a facile technique as a novel fluorescence-based sensing platform for detecting Cu(II) in aqueous solutions, and in the serum samples of healthy and affected individuals by WD. The CQDs interact with Cu(II) ions to produce Turn-on and Turn-off states at nano-molar and micro-molar levels, respectively, with LODs of 0.001 µM and 1 µM. In fact, the Cu2+ ions can act like a bridge between two CQDs by which the charge and electron transfer between the CQDs may increase, possibly can have significant effects on the spectroscopic features of the CQDs. To the best of our knowledge, this is the first reported research that can detect Cu(II) at low levels using two different complexation states, with promising results in testing serum. The potential of the sensor to detect Cu(II) was tested on serum samples from healthy and affected individuals by WD, and compared to results obtained by ICP-OES. Astonishingly, the results showed an excellent correlation between the measured Cu(II) levels using the proposed technique and ICP-OES, indicating the high potential of the fluorimetric CQD-based probe for Cu(II) detection. The accuracy, sensitivity, selectivity, high precision, accuracy, and applicability of the probe toward Cu(II) ions make it a potential diagnostic tool for Wilson's disease in a clinical setting.

A comparative study of structural and catalytic activity alterations in firefly luciferase induced by carbon quantum dots containing amine and carboxyl functional groups.

Despite of growing interest in use of carbon-based nanomaterials as carriers of functional proteins, less attention has been paid to the effects of these nanomaterials on the structure and function of the proteins. In this study, with the aim of shedding light on the mechanisms of interaction between carbon-based nanomaterials and proteins, the interactions of carbon quantum dots (CQDs) containing amine (CQD-NH2) or carboxyl groups (CQD-COOH) with Photinus pyralis firefly luciferase enzyme were investigated by experimental and computational approaches. The structural changes and reduction in activity of the luciferase upon treatment with CQDs were experimentally proved. CQD-NH2 induced more reduction in enzyme activity (15 %) compared to CQD-COOH (7.4 %). The interactions CQD-NH2 with luciferase led to higher affinity of the enzyme for its substrate. It was found by molecular dynamic simulations that CQD-NH2 binds to multiple regions on the surface of luciferase. Secondary structure analysis showed that CQD-NH2 had more profound effects on the active site amino acids, the adjacent amino acids to the active site and the residues involved in ATP binding site. In addition, CQD-NH2 interactions with luciferase were suggested to be stronger than CQD-COOH based on the number of hydrogen bonds and the binding energies.

Palladium-based pseudohomogeneous catalyst for highly selective aerobic oxidation of benzylic alcohols to aldehydes.

This study presents a novel class of pseudohomogeneous catalysts (PHC) based on carbon quantum dots functionalized with terpyridine ligands (CQDs-Tpy) to immobilize and stabilize palladium nanoparticles (Pd NPs). Extensive characterization techniques clearly confirmed the successful stabilization of Pd NPs on CQDs-Tpy. The effectiveness of the catalyst was demonstrated in the selective aerobic oxidation of primary and secondary of benzylic alcohols to aldehydes in the absence of additives and phase transfer catalyst (PTC). Remarkably, the reactions predominantly yielded aldehydes without further oxidation to carboxylic acids. By employing low catalyst loadings (0.13 mol%), high conversions (up to 89%) and excellent selectivity (> 99%) of the aldehyde derivatives were achieved. Moreover, the CQDs-Tpy/Pd NPs catalyst displayed suitable catalytic activity and recyclability, offering potential economic advantages. This promising approach opens up new opportunities in the field of catalysis for designing subnanometric metal-based PHCs.

Photocatalytic removal of imidacloprid pesticide from wastewater using CdS QDs passivated by CQDs containing thiol groups.

Over the past decade, CdS QDs have become versatile semiconductors. Surface modification of CdS QDs has become an interesting case study, as it can eliminate surface defects and improve their photochemical properties. In this study, we report a new strategy of using carbon quantum dots containing a large number of thiol groups (CQDs-SH) as a passivating agent for the stabilization of CdS quantum dots (QDs). Various characterization techniques have clearly revealed that the CdS QDs have been successfully passivated by CQDs-SH. The photocatalytic performance of CQDs-SH/CdS QDs was investigated for the degradation of the insecticide imidacloprid from an aqueous solution. Parameters affecting the photodegradation process, including the light source, photocatalyst amount, initial concentration of the pollutant, radiation time, pH, oxidizing agent, and temperature, were investigated. Furthermore, the HPLC technique was applied to quantitatively analyze imidacloprid and its degradation products. The results of the HPLC analysis revealed that under simulated visible light at pH 9, imidacloprid scarcely existed after 90 min of irradiation (90.13% degradation). The LC-MS method was also used to detect the degradation products and investigate the mechanism of photodegradation of the pesticide. The results showed that the CQDs-SH/CdS QDs composite was a promising photocatalyst for the degradation of imidacloprid in wastewater.

Chiral Pseudohomogeneous Catalyst Based on Amphiphilic Carbon Quantum Dots for the Enantioselective Kharasch-Sosnovsky Reaction.

The term "chiral pseudohomogeneous catalyst (PHC)" denotes a novel concept that characterizes subnanometric particles exhibiting atomic-level chirality. The PHC based on chiral amphiphilic carbon quantum dots possesses distinctive features that combine the strengths of both homogeneous and heterogeneous catalysts, thereby heralding a significant breakthrough in the fields of asymmetric synthesis and medicinal chemistry. To the best of our knowledge, this is the first and the only reported research of a chiral PHC that demonstrates exceptional performance in controlling the enantioselectivity of the Kharasch-Sosnovsky reaction, yielding the corresponding products in high conversion (95%) with a moderate enantiomeric excess (75%). Notably, the chiral information on l-tryptophan can be effectively transferred from the outer shell of the nanosized catalyst, thereby inducing enantioselectivity in C-H activation and subsequent C-O forming events. Additionally, we have investigated the impact of various factors on the allylic oxidation reaction, including the amount, diversity, and hydrophilic/hydrophobic nature of the catalyst, as well as the influence of the solvent, Cu salts, temperature, and the type of alkene and perester, in order to comprehensively explore the reaction conditions. Furthermore, the catalyst can be readily recycled from the reaction medium, making this PHC a promising innovation that can significantly impact practical applications. In summary, this breakthrough can be aptly described as a "Golden Gate" due to its unparalleled potential to open up novel avenues for research and innovation.

Screening of honey bee pollen constituents against COVID-19: an emerging hot spot in targeting SARS-CoV-2-ACE-2 interaction.

The attachment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike to angiotensin-converting enzyme 2 (ACE-2) leads the cell fusion process, so spike blockade may be a promising therapy combating COVID-19. Bee pollen bioflavonoids with intrinsic bioactivities are of outmost importance to block SARS-CoV-2-ACE-2 interaction. Herein, we conducted a molecular docking assessment through natural phenolics/non-phenolics of pollen to investigate their affinity against SARS-CoV-2 spike. Finally, kaempferol 3-neohesperidoside 7-O-rhamnoside (compound a), quercetin 7-rhamnoside (compound b), delphinidin-3-O-(6-p-coumaroyl) glucoside (compound c), and luteolin-7-O-6″-malonylglucoside (compound d) showed the lowest binding affinity of -8.1, -7.7, -7.3 and -6.7 kcal/mol. The docking procedure was validated using protein-protein interactions between ACE-2 and SARS-CoV-2 RBD via HADDOCK webserver. MD simulations were fulfilled to investigate different ligands' effects on protein movements. Collectively, compound a may possess the potency to disturb the binding of SARS-CoV-2 spike-ACE-2, which can be on the call for further in vitro and in vivo study to investigate its antiviral potential against SARS-CoV-2.

Immobilization of modular peptides on graphene cocktail for differentiation of human mesenchymal stem cells to hepatic-like cells.

In this study, two novel biomimetic modular peptide motifs based on the alpha-2 subunit of type IV collagen (CO4A2) were designed and immobilized on a graphene platform to imitate integrin and heparan sulfate- (HS-) binding proteins. The in silico study was used to design 9-mer K[KGDRGD]AG and 10-mer KK[SGDRGD]AG for testing designed Integrin-Binding Peptide (dIBP) and HS-Binding Peptide (dHBP). The virtual docking technique was used to optimize the peptide motifs and their relevant receptors. Molecular dynamic (MD) simulation was used to evaluate the stability of peptide-receptor complexes. The effect of the platform on the differentiation of human mesenchymal stem cells (hMSCs) to hepatic-like cells (HLCs) was evaluated. After differentiation, some hepatic cells' molecular markers such as albumin, AFP, CK-18, and CK-19 were successfully followed. Graphene-heparan sulfate binding peptide (G-HSBP) enhances the mature hepatic markers' expression instead of control (p ≤ 0.05). The pathological study showed that the designed platform is safe, and no adverse effects were seen till 21 days after implantation.

Design and Preparation of Copper(II)-Mesalamine Complex Functionalized on Silica-Coated Magnetite Nanoparticles and Study of Its Catalytic Properties for Green and Multicomponent Synthesis of Highly Substituted 4H-Chromenes and Pyridines.

In the present study, a green and ecofriendly nanocatalyst was synthesized through functionalization of 2,4,6-trichloro-1,3,5-triazine (TCT) and mesalamine on silica-coated magnetic nanoparticles (MNPs), then coordination with Cu2+ without agglomeration, consecutively. The silica-coated MNPs functionalized with the Cu(*II)-mesalamine complex was (Fe3O4@SiO2@NH2-TCT-mesalamine-Cu(II) MNPs) completely characterized by FT-IR, XRD, EDX, FESEM, TEM, VSM, TGA, and BET analyses. Afterward, the activity of the novel catalyst was investigated in the synthesis of chromene heterocycles, which were an important group of organic compounds. The activity of Fe3O4@SiO2@NH2-TCT-mesalamine-Cu(II) MNPs as a high-performance heterogeneous nanocatalyst was evaluated for the synthesis of 2-amino-4-aryl-6-(phenylthio)pyridine-3,5-dicarbonitriles and 2-amino-4H-chromenes via aromatic aldehydes, malononitrile, and enolizable C-H acids (resorcinol, 2-hydroxynaphthalene-1,4-dione, and benzenethiol) in ethanol under reflux conditions. Fe3O4@SiO2-TCT-mesalamine-Cu(II) could be quickly separated using an external magnet and reused nine times without a remarkable reduction of its catalytic activity.

Ultrasound-assisted pseudohomogeneous tungstate catalyst for selective oxidation of alcohols to aldehydes.

The idea of applying ultrasound (US) as a green activation method in chemical transformations, especially in catalytic alcohol oxidations, technically and ecologically appeals to chemists. In the present work, as an attempt to fulfill the idea of designing an eco-friendly system to oxidize alcoholic substrates into corresponding aldehydes, we developed multifunctional tungstate-decorated CQD base catalyst, A-CQDs/W, and examined its sonooxidation performance in presence of H2O2 as a green oxidant in aqua media. By comparing the catalyst performance in oxidize benzyl alcohol as a testing model to benzaldehyde (BeOH) prior and after US irradiation-trace vs 93%- the key role of ultrasonic irradiation in achieving high yield is completely appreciated. Exceptional thermal and compression condition that is created as a result of acoustic waves is in charge of unparalleled yield results in this type of activation method. The immense degree of reagent interaction in this method, ensures the maximum yield in notably low time, which in turn leads to decrease in the number of unreacted reagents and by-products. Meanwhile, the need for using toxic organic solvents and hazardous oxidants, auxiliaries and phase transfer catalyst (PTC) is completely obviated.

Magnetic Silica-Coated Picolylamine Copper Complex [Fe3O4@SiO2@GP/Picolylamine-Cu(II)]-Catalyzed Biginelli Annulation Reaction.

An efficient and heterogeneous novel magnetic silica-coated picolylaminecopper complex [Fe3O4@SiO2@GP/Picolylamine-Cu(II)] was synthesized, characterized, and employed as a magnetically recoverable nanocatalyst in Biginelli condensation for the preparation of biologically active 3,4-dihydropyrimidinones. Fe3O4@SiO2@GP/Picolylamine-Cu(II) was synthesized easily using chemical attachment of the picolylaminecompound on Fe3O4@SiO2@GP, followed by treatment with copper salt in ethanol under reflux conditions. Fe3O4@SiO2@GP/Picolylamine-Cu(II) was affirmed by various analyses such as Fourier transform infrared, thermogravimetric analysis, X-ray diffraction, vibrating-sample magnetometry, field-emission scanning electron microscopy, transmission electron microscopy, DLS, inductively coupled plasma, energy-dispersive X-ray spectrometry, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller. The resulting catalyst system was successfully used in the Biginelli reaction through a variety of compounds such as aromatic aldehyde, urea, and ethyl acetoacetate under solvent-free conditions or ethylene glycol at 80 °C and yielded the desired products with high conversions with powerful reusability. The current approach was convenient and clean, and only 0.01 g of the catalyst could be used to perform the reaction. The easy work-up procedure, gram-scale synthesis, usage of nontoxic solvent, improved yield, short reaction times, and high durability of the catalyst are several remarkable advantages of the current approach. Also, the Fe3O4@SiO2@GP/Picolylamine-Cu(II) nanocatalyst could be recycled by an external magnet for eight runs with only a significant loss in the product yields.

In silico evaluation of COVID-19 main protease interactions with honeybee natural products for discovery of high potential antiviral compounds.

This research investigates antiviral potential of extracted honeybee products against COVID-19 main protease (Mpro) by computational methods. The crystal structure of COVID-19 Mpro was obtained from the protein data bank. Six synthetic drugs with antiviral properties were used as control samples in order to compare the results with those of natural ligands. The six honeybee components, namely 3,4,5-Tricaffeoylquinic acid, Kaempferol-3-O-glucoside, (E)-2'-Geranyl-3',4',7-Trihydroxyflavanone, 6-Cinnamylchrysin, (+)-Pinoresinol, and (24E)-3-Oxo-27,28-dihydroxycycloart-24-en-26-oic acid, have represented the lowest binding energies of -9.0, -8.5, -8.2, -7.8, -7.7, -7.3 and -6.7 Kcal/mol, respectively. These natural inhibitors were then picked for further investigations on their pharmacokinetic features. Also a 150 ns of Molecular dynamics simulations were carried out in order to evaluate their effects on protein structure and dynamics. The 3, 4, 5-Tricaffeoylquinic acid is hopefully proposed for COVID-19 Mpro inhibition if further in vitro, in vivo, and clinical trial studies will approve its effectiveness against COVID-19.

Design of a Schiff Base Complex of Copper Coated on Epoxy-Modified Core-Shell MNPs as an Environmentally Friendly and Novel Catalyst for the One-Pot Synthesis of Various Chromene-Annulated Heterocycles.

An ecofriendly inorganic-organic hybrid and novel Schiff base complex of copper coated on epoxy-modified Fe3O4@SiO2 MNPs was successfully designed and prepared from readily available chemicals. In this method, a Schiff base complex as a linker is utilized to protect copper nanoparticles to the core-shell Fe3O4 exterior without agglomeration. The resulted Schiff base complex of copper coated on epoxy-modified Fe3O4@SiO2 MNPs was characterized and confirmed via different analyses such as FT-IR, TGA, XRD, VSM, FE-SEM, TEM, ICP, EDX, and BET. The novel catalyst was examined for the synthesis of various chromene-annulated heterocycles through the one-pot three component reaction of aromatic aldehydes, various phenols (2-hydroxynaphthalene-1,4-dione/resorcinol/ß-naphthol), and malononitrile in ethanol at reflux conditions. This method includes important aspects like no usage of column chromatography, very short reaction times, simplicity of product isolation using ethanol, excellent yields, simple procedures, and magnetic recoverability of the catalyst. All in all, our method makes a novel and significant advancement in the synthesis of various chromene-annulated heterocycles.

A pseudohomogeneous nanocarrier based on carbon quantum dots decorated with arginine as an efficient gene delivery vehicle.

A pseudohomogeneous carrier as an emerging term refers to subnanometric carbon-based vehicle with a high ability to interact with genetic materials to form stable carboplex and successfully transfer them into the cell which will result in inhibiting or expressing of therapeutic genes. Chitosan is a non-toxic polyaminosaccharide used as a precursor in the presence of citric acid to produce carbon quantum dots (CQDs), which decorated with arginine as a surface passivation agent with high amine density in hydrothermal methodology. The Arginine-CQDs are comprehensively characterized by Fourier-transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-vis), Atomic force microscopy (AFM), field emission scanning electron microscope (FE-SEM), Energy-dispersive X-ray (EDX) mapping, fluorescence, High-resolution transmission electron microscopy (HR-TEM), zeta potential and X-ray powder diffraction (XRD). In this regard, for the first time, carboplex are formed by electrostatic conjugating of Arginine-CQDs with DNA to protect it from enzymatic degradation. Moreover, the carboplex, like the chitosan precursor, has not shown toxicity against AGS cell line. Interestingly, the Arginine-CQDs have exhibited an excellent ability to overcome cell barriers to deliver into cells compared to chitosan at the same weight ratio. The Arginine-CQDs/pEGFP (W/W) nanocomplex, not only lead to transfection with a relatively higher efficiency than PEI polymer, which is the "golden standard", but carboplex also demonstrates no significant toxicity. Indeed, the EGFP expression level has reached to 2.4 ± 0.2 via Arginine-CQDs carboplex at W/W 50 weight ratio. To the best of our knowledge, this is the first report includes chitosan-based CQDs functionalized by arginine which is applied to serve as a pseudohomogeneous vehicle for gene transfection.

Pseudohomogeneous metallic catalyst based on tungstate-decorated amphiphilic carbon quantum dots for selective oxidative scission of alkenes to aldehyde.

Herein, we present an interesting role of tungstate-decorated amphiphilic carbon quantum dots (A-CQDs/W) in the selective oxidative cleavage of alkenes to aldehydes. In this work, for the first time, we disclose an unprecedented tungstate-based oxidative system incorporating A-CQDs as a bridge to the homogeneous catalyst for selective and efficient cleavage of a wide substrate scope of alkenes into aldehydes. The A-CQDs/W were synthesized via a one-step hydrothermal synthesis approach using 1-aminopropyl-3-methyl-imidazolium chloride and stearic acid for the surface modification, following by anion-exchange to immobilize WO4-2 to A-CQDs. The A-CQDs/W act as a pseudohomogeneous metallic catalyst (PMC) for selective oxidative scission of alkenes under phase transfer catalysts (PTC) free condition without over oxidation to acids, using water and H2O2 as a green oxidant. Thanks to the sub-nanometric size and novel engineered chemical structure, this PMC and reactants are in the same phase, besides they can be easily isolated from each other by extraction processes. The synthesized PMC exhibited excellent solubility and stability in various solvents. Interestingly, the system's high conversion efficiency was preserved even after eight catalytic cycles indicating the recyclability of the synthesized PMC. We believe that this study provides a significant and conceptually novel advance in oxidative cleavage chemistry.

Amphiphilic Carbon Quantum Dots as a Bridge to a Pseudohomogeneous Catalyst for Selective Oxidative Cracking of Alkenes to Aldehydes: A Nonmetallic Oxidation System.

The oxidative cleavage of alkenes to the corresponding aldehydes using new amphiphilic carbon quantum dots (A-CQDs) as a pseudohomogeneous carbocatalyst is achieved for the first time through green and sustainable chemical processes. In this work, we successfully design a recyclable pseudohomogeneous catalyst based on A-CQDs, which is decorated with 1-aminopropyl-3-methyl-imidazolium chloride and stearic acid. The functionalization is conducted to introduce a hydrophilic/hydrophobic functionality on the surface of the catalyst to achieve high catalyst availability in polar and nonpolar media with the green goal of eliminating organic (co)solvents and additives. This amphiphilic carbocatalyst provides high mass transferability to the biphasic system, which is beneficial to promoting the oxidative cracking of a variety of olefins into corresponding aldehydes with a substrate/A-CQD ratio of 150. Around 87% of the substrates are converted to the related aldehydes using the carbocatalyst in the presence of H2O2, in pure water, without using a phase-transfer catalyst or any additives and organic solvents, which is comparable with the current metal-based cleavage systems. Surprisingly, A-CQDs exhibit high catalytic activity for the scission of electron-deficient C═C bond of coumarin derivatives, accompanied by the cleavage of C-O bonds to produce the corresponding salicylaldehyde derivatives without overoxidation to acid. As a brief conclusion, A-CQDs exhibit high conversion efficiency without significant loss of activity even after six catalytic cycles. The conversion of alkenes into aldehydes is fast and high-throughput without overoxidation to acids and is accompanied by excellent solubility and stability in various solvents. Moreover, the product and the catalyst are recoverable from the reaction medium by simple extraction. So, this pseudohomogeneous carbocatalyst promises new horizons in imminent "catalytic age". All in all, this paper provides a significant and novel advancement in carbocatalyst chemistry.

Sophisticated polycaprolactone/gelatin nanofibrous nerve guided conduit containing platelet-rich plasma and citicoline for peripheral nerve regeneration: In vitro and in vivo study.

Peripheral nerve injury (PNI) is a devastating condition that may result in loss of sensory function, motor function, or both. In the present study, we construct an electrospun nerve guide conduit (NGC) based on polycaprolactone (PCL) and gelatin filled with citicoline bearing platelet-rich plasma (PRP) gel as a treatment for PNI. The NGCs fabricated from PCL/Gel polymeric blend using the electrospinning technique. The characterizations demonstrated that the fabricated nanofibers were straight with the diameter of 708 ±â€¯476 nm, the water contact angle of 78.30 ±â€¯2.52°, the weight loss of 41.60 ±â€¯6.94% during 60 days, the tensile strength of 5.31 ±â€¯0.97 MPa, and the young's modulus of 3.47 ±â€¯0.10 GPa. The in vitro studies revealed that the PCL/Gel/PRP/Citi NGC was biocompatible and hemocompatible. The in vivo studies conducted on sciatic nerve injury in rats showed that the implantation of PCL/Gel/PRP/Citi NGC induced regeneration of nerve tissue, demonstrated with histopathological assessments. Moreover, the sciatic function index (SFI) value of -30.3 ±â€¯3.5 and hot plate latency time of 6.10 ±â€¯1.10 s revealed that the PCL/Gel/PRP/Citi NGCs recovered motor and sensory functions. Our findings implied that the fabricated NGC exhibited promising physicochemical and biological activates favorable for PNI treatment.

A novel bio-inspired conductive, biocompatible, and adhesive terpolymer based on polyaniline, polydopamine, and polylactide as scaffolding biomaterial for tissue engineering application.

A novel electrically conductive nanofibrous scaffold based on polyaniline-co-(polydopamine-grafted-poly(d,l-lactide)) [PANI-co-(PDA-g-PLA)] was fabricated using electrospinning technique and its physicochemical as well as biological characteristics toward bone tissue engineering (TE) were investigated extensively. In detail, PANI-co-PDA was synthesized via a one-step chemical oxidization approach. Then, d,l-lactaide monomer was grafted onto PDA segment using a ring opening polymerization (ROP) to afford PANI-co-(PDA-g-PLA) terpolymer. The successful synthesis of PANI-co-(PDA-g-PLA) terpolymer was confirmed using FTIR spectroscopy as well as TGA analysis. Finally, a solution of the synthesized terpolymer was electrospun to fabricate a conductive nanofibrous scaffold. Some physicochemical features such as mechanical, conductivity, electroactivity, hydrophobicity, and morphology as well as biological characteristics including biocompatibility, biodegradability, as well as enhancing the cells adhesion and proliferation were investigated. According to the above-mentioned experimental results, the fabricated electrospun nanofibers can be considered as a potential scaffold for TE application, mainly due to its proper physicochemical and biological properties.

Targeted Development of Sustainable Green Catalysts for Oxidation of Alcohols via Tungstate-Decorated Multifunctional Amphiphilic Carbon Quantum Dots.

Achieving green and sustainable chemical processes by replacing organic solvents with water has always been one of the green chemistry goals and a challenging topic for chemists. However, the poor solubility of organic materials is a major limitation to achieving this goal, especially in alcohol oxidation. In this contribution, the development and design of amphiphilic catalysts via abundant, safe, cheaper, and more biocompatible sources have received notable attention. To this purpose, herein, our group successfully synthesized a new multifunctional amphiphilic carbon quantum dot (CQD) composed of 1-aminopropyl-3-methyl-imidazolium chloride ([APMim][Cl]), dodecylamine (DDA), and citric acid (CA) (denoted as CQDs@DDA-IL/Cl) using a one-pot hydrothermal route. The CQDs@DDA-IL/Cl was then utilized as an amphiphilic stabilizer for anchoring tungsten ions using an anion-exchange method (marked as CQDs@DDA-IL/W). The CQDs@DDA-IL/W as a reusable catalyst selectivity mediated the oxidation of alcoholic substrates with stoichiometric H2O2 in water solvent. The extraordinary performance of our catalyst was attributable to the coexistence of ionic liquid (IL) and DDA upon the surface of the CQDs@DDA-IL/W, which plays a main duty in the hydrophobic/hydrophilic balance, and significantly increase the catalyst compatibility in the aqueous medium with the purpose of removing organic solvents. As a result, the great mass transfer occurs in the two-phase medium using this amphiphilic nanocatalyst without any phase transfer catalyst (PTC) or other additives. The 100% selectivity, excellent turnover number (TON) and turnover frequency (TOF), high yield, almost complete and fast conversion of alcohol to the desired aldehydes and ketones without more oxidation, and easy and no-trouble isolation of product and catalyst are outstanding features of this catalytic system.

Cell attachment evaluation of the immobilized bioactive peptide on a nanographene oxide composite.

The immobilization of bioactive peptides as key molecules in numerous biological and physiological functions holds promise for designing advanced biomaterials. Graphene and its derivatives, having unique physicochemical properties, have brought considerable attention in the life sciences. In this regard, the chemical manipulation of the graphene surface with bioactive peptides opens a new horizon to design bioactive materials for a variety of future nanobiotechnologies. In this study, the first straightforward strategy for the covalent immobilization of the cell-adhesion peptide onto the graphene surface based on the Ugi four-component assembly process (Ugi 4-CAP) will be presented. The modified adhesion motif peptide, as an amine component in the presence of formaldehyde, cyclohexylisocyanide and carboxylated-graphene (G-COOH), was adopted in a four component reaction to fabricate a peptide-graphene (Peptide-G) biomaterial in water as a green solvent at an ambient temperature. The amino functional groups corresponded to the modified adhesion motif peptide and were immobilized onto the graphene sheets, which were quantified by the Kaiser test. The sheets were characterized by further analyses with FT-IR, AFM, UV-vis, Raman and thermogravimetric analyses. The Peptide-G biomaterial showed excellent biocompatibility. In addition, the Peptide-G treated surface, due to the presence of RGD on the surface of the graphene, significantly accelerated the proliferation of human mesenchymal stem cells (hMSCs) at a better rate regarding the tissue plate.