Mohd Qasim

Magnetically recyclable Ni0.5Zn0.5Fe2O4/Zn0.95Ni0.05O nano-photocatalyst: Structural, optical, magnetic and photocatalytic properties

A novel visible light active and magnetically separable nanophotocatalyst, Ni0.5Zn0.5Fe2O4/Zn0.95Ni0.05O (denoted as NZF@Z), with varying amount of Ni0.5Zn0.5Fe2O4, has been synthesized by egg albumen assisted sol gel technique. The structural, optical, magnetic, and photocatalytic properties have been studied by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), UV-visible (UV-Vis) spectroscopy, and vibrating sample magnetometry (VSM) techniques. Powder XRD, TEM, FTIR and energy dispersive spectroscopic (EDS) analyses confirm coexistence of Ni0.5Zn0.5Fe2O4 and Zn0.95Ni0.05O phases in the catalyst. Crystallite sizes of Ni0.5Zn0.5Fe2O4 and Zn0.95Ni0.05O in pure phases and nanocomposites, estimated from Debye-Scherrer equation, are found to be around 15-25 nm. The estimated particle sizes from TEM and FESEM data are ∼(22±6) nm. The calculated energy band gaps, obtained by Tauc relation from UV-Vis absorption spectra, of Zn0.95Ni0.05O, 15%NZF@Z, 40%NZF@Z and 60%NZF@Z are 2.95, 2.72, 2.64, and 2.54 eV respectively. Magnetic measurements (field (H) dependent magnetization (M)) show all samples to be super-paramagnetic in nature and saturation magnetizations (Ms) decrease with decreasing ferrite content in the nanocomposites. These novel nanocomposites show excellent photocatalytic activities on Rhodamin Dye.

Silver nanoparticles embedded mesoporous SiO2 nanosphere: an effective anticandidal agent against Candida albicans 077

Candida albicans is a diploid fungus that causes common infections such as denture stomatitis, thrush, urinary tract infections, etc. Immunocompromised patients can become severely infected by this fungus. Development of an effective anticandidal agent against this pathogenic fungus, therefore, will be very useful for practical application. In this work, Ag-embedded mesoporous silica nanoparticles (mSiO2@AgNPs) have successfully been synthesized and their anticandidal activities against C. albicans have been studied. The mSiO2@AgNPs nanoparticles (d ∼ 400 nm) were designed using pre-synthesized Ag nanoparticles and tetraethyl orthosilicate (TEOS) as a precursor for SiO2 in the presence of cetyltrimethyl ammonium bromide (CTAB) as an easily removable soft template. A simple, cost-effective, and environmentally friendly approach has been adopted to synthesize silver (Ag) nanoparticles using silver nitrate and leaf extract of Azadirachta indica. The mesopores, with size-equivalent diameter of the micelles (d = 4-6 nm), were generated on the SiO2 surface by calcination after removal of the CTAB template. The morphology and surface structure of mSiO2@AgNPs were characterized through x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), particle size analysis (PSA), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET) and high-resolution transmission electron microscopy (HRTEM). The HRTEM micrograph reveals the well-ordered mesoporous structure of the SiO2 sphere. The antifungal activities of mSiO2@AgNPs on the C. albicans cell have been studied through microscopy and are seen to increase with increasing dose of mSiO2@AgNPs, suggesting mSiO2@AgNPs to be a potential antifungal agent for C. albicans 077.

Investigation on a smart nanocarrier with a mesoporous magnetic core and thermo-responsive shell for co-delivery of doxorubicin and curcumin: a new approach towards combination therapy of cancer

In this work, we report on the synthesis and characterization of a novel and smart nanocarrier with a mesoporous magnetic core and thermo-responsive shell for co-delivery of hydrophilic doxorubicin (Dox) and hydrophobic curcumin (Cur) as a combinational therapy for cancer treatment. The P(NIPAM-MAm) coated mesoporous Fe3O4 (MIO-P(NIPAM-MAm)) nanocomposite was prepared by in situ cross linked polymerization of NIPAM and MAm on the surface of pre-synthesized mesoporous Fe3O4 nanoparticles (MIO NPs) in the presence of an oxidizer and cross linker. MIO NPs were synthesised by co-precipitation method using CTAB as the sacrificial soft template. Different characterization techniques have been used to study the physicochemical properties of MIO NPs and the MIO-P(NIPAM-MAm) nanocomposite. Particle sizes of the MIO-P(NIPAM-MAm) nanocomposite estimated by TEM were found to be in between 200–500 nm. VSM results show MIO and MIO-P(NIPAM-MAm) nanocomposites to be superparamagnetic in nature. MIO-P(NIPAM-MAm) nanocomposites exhibited a lower critical solution temperature (LCST) of 41 °C, which is suitable for controlled drug delivery applications unlike pure PNIPAM based nanocarriers. The encapsulation efficiency of Dox and Cur were found to be 96% and 90% respectively. Temperature dependent release studies from MIO-P(NIPAM-MAm)-Cur-Dox indicated a slower release of drugs (both Dox and Cur) below LCST and a sustained release above LCST. Different mathematical models (such as zero order, first order, Higuchi and Korsmeyer–Peppas) were used to fit the experimental release profiles of both drugs. MTT assays on normal and HeLa cells demonstrated the non-toxic nature of the MIO-P(NIPAM-MAm) nanocomposite. The co-loaded MIO-P(NIPAM-MAm)-Cur-Dox nanocomposite exhibited higher in vitro anti-cancer activity compared to free Dox, free Cur, and a free Dox + free Cur mixture. Such a co-loaded smart delivery system could have potential for controlled and targeted drug delivery in cancer diagnosis.

Investigation of novel superparamagnetic Ni0.5Zn0.5Fe2O4@albumen nanoparticles for controlled delivery of anticancer drug

In the present work, multifunctional Ni0.5Zn0.5Fe2O4@albumen (NZF@Alb) and doxorubicin-loaded Ni0.5Zn0.5Fe2O4@albumen (NZF@Alb-Dox) core-shell nanoparticles have been prepared by a green and simple method using inexpensive chicken egg albumen and have been characterized for different physiochemical properties. The structural, morphological, thermal, and magnetic properties of the prepared nanoparticles have been investigated by an x-ray diffractometer, high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy, Fourier-transformed infrared, thermogravimetric analysis, and vibrating sample magnetometer techniques. Superparamagnetic Ni0.5Zn0.5Fe2O4 nanoparticles (NZF NPs) with the mean size ∼20 nm were coated with albumen matrix by an ultrasonication process. Inverse fast Fourier transform-assisted HRTEM micrographs and FTIR analysis revealed the coating of amorphous albumen on crystalline NZF NPs. NZF@Alb and NZF@Alb-Dox NPs have the mean size (D50) of ∼100 nm, good stability, and magnetic controllability. Magnetic measurements (field (H)-dependent magnetization (M)) show all samples to be super-paramagnetic in nature. Biocompatibilities of the NZF and NZF@Alb NPs were confirmed by in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against RAW 264.7 cells. NZF@Alb NPs have been found to be more biocompatible than bare NZF. In Vitro Dox release behavior from NZF@Alb-Dox NPs has been studied at pH 7.4 and 5, and a sustained and pH-dependent drug release profile were observed. In vitro cytotoxicity or anticancer activity of the blank NZF@Alb NPs, free Dox, and NZF@Alb-Dox NPs against HeLa cells (cancer cell line) were also examined by MTT assay. The obtained results suggest that this scalable egg-albumen-based magnetic nanoformulation is suitable for targeted drug delivery applications. Thus, the present study could be extremely useful for the advancement of albumin-based nanocarrier design and development for biomedical applications such as targeted and controlled delivery of anticancer drugs.

Synthesis and Characterization of Ni0.5Zn0.5Fe2O4@mSiO2 Core Shell Nanocarrier for Drug Delivery Applications

Ni0.5Zn0.5Fe2O4@mesoporousSiO2 (NZF@mSiO2) core shell nanocarrier was synthesized by sol–gel method using tetraethyl orthosilicate (TEOS) and cetyltrimethylammonium bromide (CTAB) and characterized for different physicochemical properties. The structural and morphological properties were studied by X-ray powder diffraction (XRD), transmission electron microscope (TEM), and field emission scanning electron microscope (FESEM) techniques. XRD pattern and TEM micrographs confirm the coexistence of Ni0.5Zn0.5Fe2O4 and SiO2 phases in the nanocomposites. Average crystallite size of Ni0.5Zn0.5Fe2O4 NPs was found to be around ~21 nm. Particles size of NZF@mSiO2 measured by TEM and FESEM are found to be ~200–400 nm. High-resolution transmission electron microscopy (HRTEM) results confirm successful formation of NZF@mSiO2 core shell nanocomposites having well symmetric structure and ellipsoidal shape. HRTEM analysis confirmed the presence of pores (5–10 nm) on the surface of SiO2 nanosphere. Magnetic properties of NZF@mSiO2 nanocarriers were studied by vibrating sample magnetometer (VSM) technique. NZF@mSiO2 nanocarriers were found to be super-paramagnetic in nature with negligible coercivity and remanent magnetization. The Ms value for NZF@mSiO2 was found to be 9.5 emu/gm.

Facile synthesis of Fe3O4 and multifunctional Fe3O4@Albumen nanoparticles for biomedical applications

In this work two different sizes of Fe3O4 nanoparticles (NPs) have successfully been synthesized by changing reaction parameter. Prepared Fe3O4 NPs have been characterized for its structural, morphological, and magnetic properties by using XRD, FESEM, TEM, SAED and VSM techniques. XRD and SAED patterns confirmed the formation of cubic phase Fe3O4 NPs. Crystallite sizes estimated using the Debye–Scherrer equation of both prepared Fe3O4 NPs using less (S1) and more (S2) NaBH4 were found to be ~9 and ~18 nm respectively. Both TEM and FESEM results suggested nearly spherical and random morphology of both S1 and S2 prepared Fe3O4 NPs with average particles sizes of 22 and 27 nm respectively. VSM result revealed superparamagnetic nature of the prepared Fe3O4 NPs. In the last section of this work, prepared Fe3O4 NPs have successfully been coated with albumen to form biocompatible multifunctional Fe3O4@Alb nanoparticle. These Fe3O4@Alb NPs may find potential applications in targeted drug delivery due to its magne...

One-pot green synthesis of carbon quantum dot for biological application

A one-pot microwave assisted method for synthesizing carbon quantum dots (CQDs) from honey is presented in this paper. The structural, morphological and optical properties of synthesized CQDs were characterized by XRD, TEM, UV-Vis spectrophotometer, and Raman techniques. The average particle size of CQDs is found to be 2 to 7 nm. The main advantage of this work is the use of inexpensive, less toxic and environmental friendly precursors and synthesis procedure for CQDs. In addition to this, the particle size of prepared CQDs was found to be ultrafine with narrow size distribution. The as-prepared CQDs, with smaller particle size, good stability, good optical properties, water dispersibility and low toxicity, show promising potential for applications in biomedical field.