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Abstract: We Successfully synthesized novel silica-supported Ni (II)-PLP-ONNO Schiff base/SBA-15 complex, as a mesoporous catalyst, whose characterization was determined using X-ray diffraction analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma-atomic emission spectroscopy, nitrogen adsorption desorption isotherms (BET-EDX) and (BET-BJH), and thermo-gravimetric analysis. As a fabricated catalyst was employed, for facile and efficient, one-pot production of various benzothiazole heterocycles by cyclocondensation reactions of 2-amionthiophenol and benzaldehyde compounds under green and mild conditions with good to excellent yields. The prepared nano catalyst can offer high stability, excellent activity, easy separation, and reusability, as well environmentally friendly, compared to its homogeneous compounds.

This study aimed to synthesize a silver nanocomposite hydrogel based on poly (acrylic acid) and poly (vinyl pyrrolidone) grafted onto salep biopolymer and its use in controlled drug release. Drug release is one of the medicine goals that have been happening in the different methods, such as injections, pills or sprays. The useful drug dose, has measured by the drug concentration in the blood system, in the specific time. Researches have shown, in above methods, at the first time there is a high concentration of drug in the blood and by passing the time, this concentration decreases, so for achieve the useful drug dose, more drug is needed which it usually causes the increasing of the drug side effects. Thus for preventing these side effects, controlled drug release is investigated in this research. To identify the synthesized hydrogel, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermometric gravimetric analysis (TGA) were used. The results showed that the release of deferasirox from the silver nanocomposite hydrogel network is related to the pH of the environment. In addition, the biodegradability and biocompatibility of this system have led to its use in the pharmaceutical industry.

An exceptionally productive and sustainable procedure is described in this paper to fabricate 1-(benzothiazolylamino) methyl-2-naphthols using a novel green nanocomposite of chitosan and diethylenetriamine-modified graphene oxide, supported methanesulfonic acid (Ch@GO-DETA.MSA.). For the synthesis of the nanocomposite, maleic anhydride was first attached to chitosan, and then, graphene oxide was modified by diethylenetriamine (GO@DETA). Subsequently, nanocomposite was prepared from the reaction of chitosan-g-maleic anhydride and GO@DETA. Finally, methane sulfonic acid was added to the nanocomposite to afford Ch@GO-DETA.MSA. Structural properties of the nanocomposite were explored through various techniques including X-ray diffraction (XRD), thermal gravimetric analysis (TGA), FTIR spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). 1-(Benzothiazolylamino) methyl-2-naphthols were efficiently prepared in high to excellent yields through a multicomponent reaction of 2-aminobenzothiazole, aryl aldehydes, and 2-naphthol using Ch@GO-DETA.MSA. nanocomposite under solvent-free conditions. The proposed protocol exhibited superiority over several published protocols due to its nontoxicity and eco-friendly, catalytic ability, short reaction times, generality, efficiency, solvent-free condition, and simple workup.

Magnetic nanoparticles (MNPs) have many unique properties such as non-toxicity, suitable thermal and chemical stability, designability for different applications, environmental friendliness, high s...

Antibacterial photodynamic therapy (aPDT) has drawn increasing attention as a noninvasive approach to remove bacterial contaminants such as E. faecalis from the tooth surface. In this study, curcumin (CUR) was loaded into ZSM-5 zeolite and the prepared photosensitizers (CUR@ZSM) were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet–visible spectroscopy (UV–Vis). The loading efficiency, and release behavior of CUR were studied in CUR@ZSM. The antimicrobial and anti-biofilm potential of the photosensitizer were evaluated against E. faecalis via colony forming unit and crystal violet assays, respectively. No significant changes were observed in the size, morphology and crystallinity of the zeolite after CUR loading. CUR@ZSM showed a significant photodynamic inactivation effect through complete bacterial elimination and reduced the biofilm formation ability of E. faecalis up to about 80%. The results revealed that CUR@ZSM could be considered as a new potential photosensitizer for further study against endodontic infections.

In this work, magnetic nanocomposite hydrogel was produced via grafting copolymerization of acrylic acid (AA) and acrylamide (AAm) in the presence of MnFe2O4@SiO2@Vinyltrimethylsilane (VTMS) as a cross-linking agent. To effectively absorb Pb (II) and Cd (II) from an aqueous solution, the prepared magnetic nanocomposite hydrogel was applied. XRD, VSM, FT-IR, SEM, EDS, and TEM VSM, SEM, TEM, EDS, FT-IR, and XRD spectroscopic methods validated the structure of the prepared nanocomposite hydrogel. In addition, thermal characteristics were evaluated by TGA and DTG. The features that influence the absorption of heavy metal ions include pH solution, treatment time, starting concentration of ions, temperature, and sorbent quantity experimented. Employing Langmuir, Freundlich, and Temkin, the adsorption isotherm was investigated at various temperatures. The adsorption data best fitted The Langmuir isotherm model. The absorption kinetics models such as intraparticle, pseudo-first-order, pseudo-second-order in metal ion solutions of 25, 50, 100, and 150 mg/L-1 were studied. The absorption results were well explained by pseudo-first-order model. The maximal absorption capacities of magnetic nanocomposite hydrogel for Pb (II) and Cd (II) elimination from a 150 mg/L-1 metal solution were 131 and 126 mg/g, respectively. The absorbent was employed effectively for four cycles of adsorption and desorption. Therefore, the nanocomposite hydrogel examined in this work may be used for various water filtration purposes, notably for the elimination of toxic metals.

Under favorable conditions, we have designed a one-pot multicomponent reaction combining aromatic amines, aldehydes, nitroalkanes, and 1-dicarbonyl compounds in conjunction with the presence of the Ni(II)-Schiff base/SBA-15 as a heterogeneous catalyst to generate a range of functionalized pyrroles in reasonable to excellent yields. We present a methodology that results in a high yield percentage, a short reaction time of approximately 8 hours, mild reaction conditions of 70°C, a wide range of substrates, the possibility of large-scale synthesis, low cost, and the avoidance of hazardous reagents/solvents. In addition, this method can synthesize more desirable pyrroles by adding or altering numerous functional groups to the reactants in a one-pot process. Specifically, a Hammett plot variant was employed to evaluate the reaction effectively.

Epirubicin (EPI) is one of the standard anticancer drugs that apply for various cancers treatment. However, the accumulation of EPI in the human body can be highly toxic, and it causes inevitable harm to organs. As a result, the evaluation of low concentrations of this drug in body samples requires sensitive, rapid, and accurate analysis methods. The fluorescence method is an efficient way in comparison of the traditional methods such as liquid chromatography, capillary electrophoresis, and electrochemical methods. Herein, we synthesized a novel fluorescence nanosensor named CMC-CdTe/ZnS based on using quantum dots (QDs). The structure of the prepared nanosensor is confirmed by different analysis methods such as FT-IR, TGA, and TEM. Besides that, the fluorescence intensity response of CMC-CdTe/ZnS QDs in the presence of Epirubicin drug is investigated. Based on obtained results, not only this nanosensor developed, but also the fluorescence quenching was explained by the typical Stern–Volmer equation. The best linear quenching equation for entitled nanosensor in the presence of Epirubicin is F0/F = 0.0346Q + 1.08 (R2 = 0.99), and the detection limit of Epirubicin is around 0.04 × 10−6 mol/L at 25 °C. All of the results display that this method could be reliable and suitable approach for determination of Epirubicin in commercial samples as well.

Due to the increasing demand for monitoring diseases such as rising heart rate, diabetes, and ocular disorders wearable and implantable biomedical devices seems too essential for patients not only in the hospital but also at home or during working time. Researchers mostly try to offer valuable information on the conditions of patients as non-invasive, by using comfort biomedical device with a minimum side effect. So, small and self-powered with high sensitivity biomedical devices are recommended, among different power sources that introduced for devices, biofuel cells would be produced as power source for a range of medical devices because of its capability to generate sufficient power output compared to the primary power source. The nature of the electrode reaction and the nature of the biochemical reactions are some of the important parameters that are considered for the classification of fuel cells. Enzymatic biofuel cells due to high activity at mild conditions widely applied in pacemaker; glucometer; and smart contact lenses when compared to other kinds of biofuel cells. On the other hand, short lifespan is one of important limitations in this type of biofuel cells. So, the easiest way to overcome these challenges is to apply non-enzymatic ones. Recent studies have attempted to issue novel method for fabrication of non-enzymatic biofuel cell in order to produce a new generation which are inexpensive, disposable, selective, and sensitive in properties. However, consideration of researchers to the development of self-powered biomedical devices by using body fluids or providing electricity storage is rising.

To promote the low photocatalytic efficiency caused by the recombination of electron/hole pairs and widen the photo-response wavelength window, ZnFe2O4@ZnO-N/B/RGO and ZnFe2O4@ZnO-C3N4 ternary heterojunction nanophotocatalysts were designed and successfully prepared through a sol–gel technique. In comparison to bare ZnFe2O4 and ZnO, the ZnFe2O4-ZnO@N/B/RGO and ZnFe2O4@ZnO-C3N4 ternary products showed highly improved photocatalytic properties in the degradation of methyl orange (MO) under ultra-violet (UV) and visible light irradiation. Various physicochemical properties of the photocatalysts were evaluated through field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) analysis, X-ray diffraction (XRD), UV–visible diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. The observations indicated that the ternary heterojuncted ZnFe2O4@ZnO-N/B/RGO absorbs lower energy visible light wavelengths, which is an enhancement in the photocatalytic properties of ZnFe2O4@ZnO loaded on reduced graphene oxide (RGO) nanosheets and graphite-like carbon nitride (g-C3N4). This gives the catalyst photo-Fenton degradation properties.

In this study, a nanogel-hydrogel hybrid was synthesized to improve drug delivery system performance. First, poly (acrylic acid-N-isopropylacrylamide) nanoparticles were synthesized using acrylic acid, N-isopropylacrylamide, sodium dodecyl sulfate, and MBA in the presence of APS as a radical initiator. Then the synthesized (A-N) nanogel was added to a solution of chitosan in acetic acid and (A-N) nanogel/ CTS-A hydrogel was synthesized in the presence of AA, MBA and ASP. (A-N) nanogel/ CTS-A hydrogel was characterized by IR, SEM, EDX, TEM, DLS, TGA, DTG and BET techniques. Doxorubicin (DOX) solution was used to evaluate drug loading capacity and the amount of drug-loaded was calculated using UV analysis. Drug release behavior was investigated by placing DOX-loaded (A-N) nanogel/ CTS-A at different temperature and pH ranges. Our research indicated the drug release for both carriers was controlled by diffusion mechanism but, increasing of temperature had not influenced the drug release mechanism. However, this study suggests that by trapping nanoparticles in a hydrogel system, drug carriers with higher absorption capacity and slower kinetic release can be created.

An environmentally friendly, straightforward, and cheap synthesis of highly substituted functionalized pyrrole derivatives via one pot four-component reactions of 1,3-dicarbonyl compounds, amines, ...

Anticancer drugs play important roles in cancer treatment. However, these drugs have many disadvantages such as poor solubility, high toxicity, and serious side effects like hair loss, nausea and vomiting, anemia etc. To overcome these drawbacks, many attempts have been made to develop novel controlled drug delivery systems. They can encapsulate the drug and release it to the cancer site without leaking into other sites. The employment of multi-responsive hydrogels as a drug delivery system have some advantages over other drug delivery systems due to their ease of preparation, high efficiency, high-water content, tunable physical, and biological properties. The most advantages of these hydrogels is the volume phase transitions in their cross-linked three-dimensional networks as exposure to external stimuli such as temperature, pH, pressure, electric field, magnetic field and light. There has been research on other drug delivery systems which can respond to changes in pH and temperature for targeted drug release. Among those,gels have been studied mostly for their dual responsiveness. This provides an update on progress of gel based dual pH and temperature responsive drug delivery systems. Various systems under these categories for targeted and controlled delivery of different classes of drugs such as ant diabetic and antibiotic drugs with special emphasis on anticancer drugs are discussed in this review.

A novel cyanine 3 (Cy3)-based bio-conjugated sensor has been developed to detect target DNA or extracted RNA from COVID -19 samples using the fluorescence resonance energy transfer (FRET) experiment. A special sequence of the COVID -19 genome was selected as a complementary DNA (target DNA) part. The opposite chain of this target sequence was designed in 2 parts; one part was attached to the Cy3 organic dye (capture DNA or Cy3- DNA), and the other part was attached to the BHQ

In this paper, the synthesis of new montmorillonite nanocomposite hydrogel (MMTNH) based on poly (acrylic acid-co-acrylamide) grafted onto starch, is described. Montmorillonite (MMT) as nanometer base, acrylic acid (AA) and acrylamide (AAm) as monomers, ammonium persulfate (APS) as an initiator, N,N-methylenebisacrylamide (MBA) as a crosslinker and starch as a biocompatible polymer were prepared in aqueous solution and their amounts were optimized to attain the highest water absorbance. The optimized swelling capacity in distilled water was found to be 810 g/g. A mechanism for hydrogel formation was proposed and the structure of the product was confirmed using a set of techniques including FT-IR spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and X-ray powder diffraction. Furthermore, the swelling behaviors of the nanocomposite at different pHs, various salt with different concentrations, the mixture of solvents, were investigated. The methylene blue (MB) dye was used as model drugs to assess the loading and release by MMTNH. The pH response of this MMTNH makes it suitable for acting as a controlled delivery system. The results suggest MMTNH may find applications as promising drug delivery vehicles for drug molecules.

An efficient, rapid, and environmentally benign Ni(II)-Schiff base/SBA-15-catalyzed one-pot three-component cyclocondensation process was described via the reaction between malononitrile, 4-hydroxycoumarin, and various aldehydes in aqueous media for the synthesis of 3,4-dihydropyrano[3,2-c]chromene derivatives. This nanocatalyst was characterized using FT-IR, SEM, TGA, TEM, BET, AFM, and XRD techniques. It is possible to reuse the heterogeneous catalyst without any marked change in its catalytic activity at least five times. Other remarkable features of this method include excellent yields in pure form, convenient operation, a much milder procedure, short reaction time, simple workup and avoidance of hazardous reagents/solvents.

In this paper, a novel iron oxide nanocomposite hydrogel was prepared by simultaneous formation of superparamagnetic iron oxide nanoparticles and cross-linking of poly(acrylic acid) grafted onto sodium alginate polysaccharide. The prepared optimized hydrogel was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy with energy-dispersive X-ray analysis, atomic force microscopy, and transmission electron microscopy. Moreover, swelling capacity of the obtained hydrogel was measured at different temperatures, different pHs, absorption under load, and magnetic field to assess the sensitivity of ION–PAA-g-NaAlg hydrogel. This hydrogel was also examined as a controlled drug delivery system. Doxorubicin and tetracycline (as model drugs) release was investigated at different pHs, different temperatures, and magnetic field. The release curves were nicely fitted by the Korsmeyer–Peppas equation, and the release is controlled by polymer relaxation process.

Regarding the outbreak of the SARS Cov-2 virus pandemic worldwide, it seems necessary to provide new diagnostic methods to combat the virus. A fluorescence CdTe quantum dots-DNA (QDs-DNA) nanosensor was prepared for efficient detection of a specific target complementary DNA or RNA from the SARS Cov-2 virus using FRET experiment via forming a classic "sandwich" structure. The sequence of the complementary DNA (target DNA) is planned based on a substantial part of the SARS Cov-2 virus genome, and oligonucleotides of QDs-DNA nanoprobe are designed to complement it. The water-soluble CdTe QDs-DNA was prepared by replacing the thioglycolic acid (TGA) on the surface of QDs with capture DNA (thiolated DNA) through a ligand-exchange method. Subsequently, with the addition of complementary (target DNA) and quencher DNA (BHQ2-labeled DNA) into the QDs-DNA conjugates, sandwiched hybrids were formed. The resulting assembly brings the BHQ2-labeled DNA (as the acceptor), and the QDs (as the donor) into proximity, leading to quenching of fluorescence emission from the donor QDs through the FRET mechanism. In other words, a simple, highly sensitive, selective, and rapid approach was introduced to detect complementary DNA sequence from a specific part of the SARS Cov-2 virus genome with a detection limit of 2.52 × 10-9 mol L-1. Furthermore, the planned nanosensor was well used for the detection of RNA from SARS Cov-2 viruses in real samples with satisfactory analytical results, and the outcomes were compared with RT-PCR (Reverse Transcription Polymerase Chain Reaction) as the well-known standard method.

The addition of magnetic nanoparticles gives unique properties to hydrogels. Magnetic-sensitive gels have various applications in targeted drug delivery, separation, and sensing. One of the most advantageous aspects of using magnetic nanoparticles is their ability to respond to remote control by an external magnetic field. Microgels loaded with magnetic nanoparticles enhance control in magnetic resonance imaging. In addition, these materials change the rate of hydrogel swelling in the magnetic field. In this study, we report a novel type of magnetite nanocomposite based on poly (acrylamide-co-acrylic acid) hydrogel by simple, cost effective, and eco-friendly process in a viscous medium containing glycerol at room temperature. For this purpose, first, Fe3O4 nanoparticles were synthesized through sedimentation process. The final nanocomposite was efficiently obtained in a short reaction time under ultrasonic irradiation at room temperature and the absence of chemical initiator. The SEM images show a uniform distribution of Fe3O4 nanoparticles in the hydrogel matrix with a morphology similar to cubic crystalline lattices. The swelling behavior of the prepared magnetite nanocomposites were investigated in three different mediums and showed a fast initial swelling followed by a mild increase until attaining equilibrium. The highest and the lowest swelling was obtained in pure water and under pressure, respectively. Also, the absorption and release of two drugs, fluvoxamine and ciprofloxacin, were studied in a phosphate buffer solution at 37 °C to investigate the efficiency of entitled sonochemical prepared hydrogel nanocomposite in drug delivery field.

In this study, we synthesized the benzopyrano[3,2-c]chromene-6,8-dione derivativesby one-pot multi-component reaction of 1,3-cyclohexanedione, arylaldehydes, and 4-hydroxycoumarin under the solventless condition using Cu(II)-Schiff base/SBA-15 as a reusable heterogeneous catalyst in high yields. These kinds of catalysts are built from mesoporous silica SBA-15 which is covalently anchored with Cu(II)-Schiff base complex. The high yields, simple work-up procedure, reuseability of the catalyst, and environmentally friendly conditions are the main advantages of this method compared to the other techniques. The products were identified by using 1H NMR, mass and IR spectra, which were compared to those reported previously.

In this study, a graphene oxide nanocomposite hydrogel (GONH) based on poly(acrylic acid) grafted onto a natural salep polysaccharide was synthesized and investigated as an adsorbent for the removal of cationic dye from aqueous solution. The GONH was characterized and the absorption characteristics of the GONH adsorbent were then examined using methyl violet dye. The sorption valence, the effect of the adsorbent dose, pH, contact time, temperature and dye concentration on the removal efficiency of the dye were studied. The assessment of the adsorption isotherms showed that the Langmuir model better fits the experimental data than the Freundlich model and the Ho–McKay kinetic equation better describes the absorption kinetics than the Lagergren equation. Also, the thermodynamic parameters computed from the sorption isotherms indicated a spontaneous absorption process. The GONH is an efficient adsorbent and could be used for separation aqueous solutions.

In this study, at first, gold nanorods (GNRs) were synthesized and then they were coated with a layer of hydrogel composed of poly(N-isopropylacrylamide) (PNIPAM) grafted onto carboxymethyl cellulose (CMC) as a backbone. The chemical structure of GNRs/PNIPAM-g-CMC hydrogel was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), atomic-force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The swelling properties of the obtained GNRs/PNIPAM-g-CMC hydrogel were studied at different times and temperatures. In addition, drug release from doxorubicin-loaded GNRs/PNIPAM-g-CMC hydrogel was examined at different temperatures during time. The drug release mechanism was studied by first-order, second-order, and Ritger–Peppas models. Finally, the GNRs/PNIPAM-g-CMC hydrogel biocompatibility was tested against L929 mouse fibroblast cells by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. Our study suggests that GNRs coated with low-cost hydrogels can be excellent candidate for drug delivery systems.

This paper describes the synthesis and characterization of a pH-responsive drug release system based on cadmium telluride quantum dots capped by fluorescent dye-labeled poly (N-(2-(2-amino-ethylamino)-ethyl methacrylamide) metal-chelating polymer. Fluorescent dye is a model for an active molecule which shows our polymer can be attached to bioactive agents such as antibody or a functional drug. Furthermore, it indicates the success of ligand exchange between anchor groups on polymer surface and QDs. The polymer was synthesized using reversible addition fragmentation chain transfer polymerization, resulting in polymers with controllable molecular weights and low polydispersities. The use of diethylenetriamine allows obtaining hydrophilic polymers with amine functional groups available for conjugation with QDs. Furthermore, the amine moieties of the polymer guarantee the pH sensitivity of the system. The obtained nano carrier was monodispersed with very small diameter around 4.5 nm which confirmed by TEM. The obtained nanoparticles show low cytotoxicity in cell viability studies. The release rates of doxorubicin (DOX) anticancer drug conjugates were studied at pH 5.4 and pH 7.4. The release behavior for DOX in pH 7.4 (pH of normal cells) is

A novel optical nano-sensor for tetracycline hydrochloride (TH) detection as a small molecule model was prepared by modifying the surface of CdTe/ZnS QDs with a biopolymer based cap, called poly ((2-dimethylaminoethyl) methacrylate) grafted onto oxidized starch (OS-g- PDMAEMA), via a facile method. The preparation of the nano-sensor was optimized by employing a 4-factor Box–Behnken statistical design to achieve a nano-sensor with maximum fluorescence intensity for sensitive determination of TH in real samples. The optimized nano-sensor based on CdTe/ZnS QDs were characterized by fluorescence spectroscopy, UV–vis spectrophotometry, transmission electron microscopy (TEM), Fourier transforms infrared (FTIR) and thermo-gravimetric (TG) analysis techniques. It was found that the fluorescence intensity of modified QDS (CdTe/ZnS-OS-g-PDMAEMA QDs) at 520 nm (excitation at 375 nm) was selectively quenched in the presence of trace amounts of TH drug. In this method, a simple, highly sensitive, selective and rapid analytical approach was used for the determination of TH in the concentration range of 9.14 × 10−9 mol L−1–7.23 × 10−6 mol L−1 with a detection limit of 2.74 × 10−9 mol L−1. The designed nano-sensor can be successfully applied for the determination of TH in complex matrixes (pharmaceutical formulations, urine, saline and glucose serums) with satisfactory analytical results.

Hydrogels, nanogels, and nanocomposites show increasing potential for application in drug delivery systems due to their good chemical and physical properties. Therefore, we were encouraged to combine them to produce a new compound with unique properties for drug release systems. To this aim, we first prepared poly [(N-isopropylacrylamide)-co-(2-dimethylamino ethyl methacrylate) nanogel by copolymerization processes and then added it into the solution of poly (2-dimethylamino ethyl methacrylate)] grafted onto salep. Through dropwise addition of mixed aqueous solution of iron salts into the prepared polymeric solution, a novel hydrogel nanocomposite with excellent pH, thermo, and magnetic responsive was fabricated. The obtained hydrogel nanocomposite were characterized by Fourier transform infrared spectroscopy, thermo gravimetric analysis, X-ray diffraction, scanning electron microscopy, vibrating sample magnetometer, and atomic force micrographs. The dependence of swelling properties of hydrogel nanocomposite on the temperature, pH, and magnetic field were investigated. The release behavior of doxorubicin hydrochloride (DOX) drug from DOX loaded into synthesized hydrogel nanocomposite was investigated at different pHs, temperatures, and magnetic field. In addition, the drug release behavior from obtained hydrogel nanocomposite was monitored via different kinetic models. Lastly, the toxicity of the DOX and DOX-loaded hydrogel nanocomposite were studied on MCF-7 cells at different times. These results suggested that the obtained hydrogel nanocomposite might have high potential applications in drug delivery systems.

In this study, a facile method was introduced for preparation of a ligand-coated CdTe QDs (CdTe-L QDs) for applying as a new optical nano-sensor in determination of Cr3+ ions in aqueous solutions. The prepared CdTe-L QDs were characterized using different analytical techniques including transmission electron microscopy (TEM), UV-Vis, thermogravimetric (TG) analysis, Fourier-transform infrared (FTIR), and fluorescence spectroscopies. It was found that the fluorescence intensity of the CdTe-L QDs at 540 nm (excitation at 380 nm) was selectively quenched in the presence of trace amounts of Cr3+ ions in comparison to different metal ions. In other word, a simple, highly sensitive, selective, and rapid analytical approach was used for the determination of Cr3+ ions in the concentration range of 6.78 ± 0.05 × 10−8–3.70 ± 0.02 × 10−6 mol L−1 with a detection limit of 20.30 ± 0.03 × 10−9 mol L−1. Furthermore, the designed nano-sensor was well used for the quantification of Cr3+ ions in real samples with satisfactory analytical results, and the results were compared with the standard methods (inductively coupled plasma emission spectroscopy (ICP-OES)).

Herein, thermo/pH/magnetic-triple sensitive nanogel comprised of poly(N-isopropylacrylamide), poly(2-dimethylaminoethyl) methacrylate), sodium alginate, and magnetic graphene oxide were synthesized using N,N-methylenebisacrylamide as a crosslinking agent, sodium dodecylsulfate as a surfactant, and ammonium persulfate as an initiator. The size, chemical structure, thermal stability, and morphology of the prepared nanogel were characterized using different methods. Transmittance of the obtained nanogel was investigated at varying pH and temperature in the presence and absence of magnet. The drug loading ability of synthesized nanogel was examined at different times and concentrations of doxorubicin. Additionally, the release rate of doxorubicin as an anticancer drug from the loaded nanogel was studied at different pH and temperature in the presence and absence of magnet. The biological performance of the formed nanogel was evaluated by seeding it onto MCF-7 cells at different times and concentrations. It was found that this triple responsible nanogel might provide a perfect basis for controlled drug delivery systems.

Graphical abstract, Urgent identification of COVID-19 in infected patients is highly important nowadays. Förster or fluorescence resonance energy transfer (FRET) is a powerful and sensitive method for nanosensing applications, and quantum dots are essential materials in FRET-based nanosensors. The QDs are conjugated to DNA or RNA and used in many applications. Therefore, in the present study, novel fluorescence DNA-conjugated CdTe/ZnS quantum dots nanoprobe designed for detection of Covid-19 after extracting their RNA from saliva of hesitant people. For achieving this purpose, the water-soluble CdTe/ZnS QDs-DNA prepared via replacing the thioglycolic acid (TGA) on the surface of QDs with capture DNA (thiolated DNA) throw a ligand-exchange method. Subsequently, by adding the different concentrations of complementary (target DNA) in a mixture of quencher DNA (BHQ2-labeled DNA) and the QDs-DNA conjugates at different conditions, sandwiched hybrids were formed. The results showed that the fluorescence intensity was decreased with increasing the concentration of target DNA (as a positive control). The linear equation and regression (Y = 40.302 X + 1 and R2 = 0.98) were obtained by using the Stern-Volmer relationship. The Limit of detection (LOD) was determined 0.000823 µM. The achieved results well confirm the outcomes of the RT-PCR method in real samples.

A novel thermo/pH/magnetic-triple-responsive nanogel was synthesized by grafting N-isopropylacrylamide and acrylic acid onto sodium alginate to modify magnetic graphene oxide as a drug delivery system. The synthesized nanogel was characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), atomic force micrographs (AFM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The obtained nanogel displayed excellent reversible transmittance changes in response to pH, temperature, and magnetic field. The performance of the nanogels to load doxorubicin (DOX) drug and to sustain doxorubicin release was tested upon exposure to pH, temperature, and magnetic field variations. The mechanism of drug release was proposed in this paper by different kinetic models. In addition, the effects of nanogels and DOX-loaded nanogels on MCF-7 cells were examined and results were compared with free DOX drug. The in vitro results demonstrated that this triple-responsive nanogel can be an appropriate candidate for applications in cancer therapy.

Nanogels have been demonstrated to be desirable for hydrophilic anticancer drug delivery. This study presents a novel nanogel consisting of sodium alginate-modified graphene oxide (SA-GO) and N-isopropylacrylamide (NIPAM) for sustained delivery of doxorubicin (DOX) drug. The PNIPAM/SA-GO nanogel was studied by various techniques including scanning electron microscopy, atomic force microscopy, dynamic light scattering, Fourier transform infrared spectroscopy, and thermo-gravimetric analysis. Subsequently, the thermo-responsive behavior of the PNIPAM/SA-GO nanogel was investigated by UV–Vis spectroscopy. DOX was successfully loaded into the PNIPAM/SA-GO nanogel in order to study entrapment efficiency and drug release behavior. Moreover, biocompatibility of the DOX-loaded PNIPAM/SA-GO nanogel was examined against Hella cells and was compared with free PNIPAM/SA-GO nanogel and DOX. This work offers that the nanogels could be developed further as an effective bioactive molecule delivery system.

Some chromeno[4′,3′-b]pyrano[6,5-b]quinoline derivatives were synthesized by condensation of 2-amino-4-aryl-3-cyano-5-oxo-4H, 5H -pyrano-[3,2-c] chromenes and 1,3-cyclohexanedione in an environmentally benign and efficient method by Cu(II)-Schiff base/SBA-15 as an environmentally friendly heterogeneous and recyclable catalyst under solvent-free conditions in high yields and rates. These kinds of catalysts are built from mesoporous silica SBA-15 which was covalently anchored with Cu(II) Schiff base complex. The shorter reaction times, good yields, simple work-up procedure and environmentally friendly conditions are the main advantages of this method compared to the last one. The product was identified by its 1H NMR, mass and IR spectra, which were compared to those reported previously.

Herein, we report a fast synthesis of 1,4-dihydropyridines, decahydroacridine-1,8-diones by one-pot multi-component reaction of 1,3-cyclohexanedione or dimidone, arylaldehydes, and ammonium acetate under solvent-less condition using Cu(II)-schiff base-SBA-15 as a reusable heterogeneous catalyst in high yields. These kinds of catalysts are built from mesoporous silica SBA-15 which was covalently anchored with Cu(II) schiff base complex. The shorter reaction times, good yields, simple work-up procedure and environmentally friendly conditions are the main advantages of this method compared to the last one. This method is also the first example of synthesizing acridines by Cu(II)-schiff base-SBA-15 as an efficient catalyst in solvent-free media which can be valuable to be used or investigated for similar systems. The product was identified by its 1H NMR, mass and IR spectra, which were compared to those reported previously.

In this work, as a novel fluorescent nano-sensor, a ligand-capped CdTe QDs (CdTe-L QDs) was designed for the detection and quantification of Cu2+ ions in environmental water samples. The synthesized QDs were characterized by transmission electron microscopy (TEM), thermo-gravimetric (TG) analysis, Fourier transform infrared (FTIR), UV–Vis spectrophotometry and fluorescence spectroscopy. Optical properties of the produced nanosensor were monitored by UV–Vis and fluorescence spectrophotometry. It was observed that fluorescence intensity of the produced nano-sensor selectively quenched by adding Cu2+ ions in comparison to other metal ions tested. Using CdTe-L QDs, a rapid and facile analytical method was developed to determine Cu2+ ions in the concentration range of 5.16 ± 0.07 × 10− 8 mol L− 1–1.50 ± 0.03 × 10− 5 mol L− 1 with a detection limit of 1.55 ± 0.05 × 10− 8 mol L− 1. The nanosensor was successfully applied for the determination of Cu2+ ions in various water samples, and the results were compared with the standard method.

In the present study, a hydrothermal method was developed to prepare nalidixic acid-loaded [Zn2(bdc)2(dabco)] metal–organic frameworks. The self-assembly of primary building blocks was used for synthesis of [Zn2(bdc)2(dabco)] at room temperature. The zinc metal ion was used as a connector, 1,4-benzenedicarboxylate (bdc) as a chelating ligand, and 1,4-diazabicyclo[2.2.2]octane (dabco) as a bridging ligand. The metal organic frameworks were used as the carriers for drug delivery system, where it could entrap nalidixic acid as a model drug. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV–vis), BET nitrogen adsorption–desorption method, and scanning electron microscopy (SEM) were used for characterization of samples. The drug release was also monitored, and 96 and 62% of the loaded drug were released over 120 h at pH values of 5.0 and 7.4, respectively. The antimicrobial activities of [Zn2(bdc)2(dab...

In this study microwave irradiation was used to synthesis the silver nanocomposite hydrogel and the usefulness as an adsorbent for the preconcentration, extraction and determination of methyl red (MR) from water by dispersive solid phase extraction method was evaluated. For this purpose, silver nanocomposite hydrogel (SNH) was synthesized and characterized by thermo-gravimetric (TG) analysis, FT-IR, TEM and SEM images. The effects of some important variables such as centrifuge time (min), the pH of the methyl red solution, amount of adsorbent (g), acetone volume (mL) and chloroform volume (mL) on methyl red removal were studied using central composite design (CCD) and the optimum experimental conditions were evaluated by the desirability function (DF) combined response surface methodology (RSM). Under the optimal experimental conditions, the detection limit was found to be 1.4 μg mL− 1 for MR adsorption. The limit of quantification and the linear range of calibration curve were 4.6 μg mL− 1 and 0.1–25 μg mL− 1, respectively.

Green chemistry is one of the most important routes for the synthesis of heterocyclic compounds. In this regard, the synthesis of 2-thioxoquinazolinone derivatives was achieved by condensation of versatile materials including isatoic anhydride, amine and potassium thiocyanate in the green medium of water. This convenient and efficient method affords the desired products with good to excellent yields.

Nanogels (NGs) are three-dimensional water soluble cross-linked hydrogel materials in the nanoscale size range with a high loading capacity for guest molecules and act as drug carrier systems. In the present work, a new type of thermo/pH sensitive NG comprising salep modified graphene oxide (SMGO) with branched N-isopropylacrylamide (NIPAM) and acrylic acid (AA) was prepared. The SMGO/P(NIPAM-co-AA) NGs exhibited nanoporous structure and spherical particles with diameters about 82nm as characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The samples were also characterized by Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA) to further confirm about the formation of NGs. Doxorubicin (DOX) loaded SMGO/P(NIPAM-co-AA) NGs showed thermo/pH dependent releasing behavior: slow drug release at neutral pH and lower temperature but increased significantly in acidic pH and higher temperature, without any burst release. In addition, the NGs exhibited no effect on the cell viability in the tested concentration range up to 410μg/mL and drug release systems enhanced toxicity to HeLa cells when compared to the equivalent dose of the free drug. Overall, our results put forth NGs as potential candidates in the development of a new nanocarrier for anti-cancer drug delivery.