Mohammed Mizanur Rahman

CuO Codoped ZnO Based Nanostructured Materials for Sensitive Chemical Sensor Applications

Due to numerous potential applications of semiconductor transition metal-doped nanomaterials and the great advantages of hydrothermal synthesis in both cost and environmental impact, a significant effort has been employed for growth of copper oxide codoped zinc oxide (CuO codoped ZnO) nanostructures via a hydrothermal route at room conditions. The structural and optical properties of the CuO codoped ZnO nanorods were characterized using various techniques such as UV-visible, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), etc. The sensing performance has been executed by a simple and reliable I-V technique, where aqueous ammonia is considered as a target analyte. CuO codoped ZnO nanorods of thin film with conducting coating agents on silver electrodes (AgE, surface area of 0.0216 cm(2)) displayed good sensitivity, stability, and reproducibility. The calibration plot is linear over the large dynamic range, where the sensitivity is approximately 1.549 ± 0.10 μA cm(-2 )mM(-1) with a detection limit of 8.9 ± 0.2 μM, based on signal/noise ratio in short response time. Hence, on the bottom of the perceptive communication between structures, morphologies, and properties, it is displayed that the morphologies and the optical characteristics can be extended to a large scale in transition-metal-doped ZnO nanomaterials and efficient chemical sensors applications.

Iron Oxide Nanoparticles

Mohammed M. Rahman1, Sher Bahadar Khan1,2, Aslam Jamal3, Mohd Faisal3 and Abdullah M. Aisiri1,2 1The Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah 2Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 3Centre for Advanced Materials and Nano-Engineering (CAMNE), Department of Chemistry, Faculty of Sciences and Arts, Najran University, Najran Kingdom of Saudi Arabia

Efficient 2-Nitrophenol Chemical Sensor Development Based on Ce2O3 Nanoparticles Decorated CNT Nanocomposites for Environmental Safety

Ce2O3 nanoparticle decorated CNT nanocomposites (Ce2O3.CNT NCs) were prepared by a wet-chemical method in basic medium. The Ce2O3.CNT NCs were examined using FTIR, UV/Vis, Field-Emission Scanning Electron Microscopy (FESEM), X-ray electron dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). A selective 2-nitrophenol (2-NP) sensor was developed by fabricating a thin-layer of NCs onto a flat glassy carbon electrode (GCE, surface area = 0.0316 cm2). Higher sensitivity including linear dynamic range (LDR), long-term stability, and enhanced electrochemical performances towards 2-NP were achieved by a reliable current-voltage (I-V) method. The calibration curve was found linear (R2 = 0.9030) over a wide range of 2-NP concentration (100 pM ~ 100.0 mM). Limit of detection (LOD) and sensor sensitivity were calculated based on noise to signal ratio (~3N/S) as 60 ± 0.02 pM and 1.6×10−3 μAμM-1cm-2 respectively. The Ce2O3.CNT NCs synthesized by a wet-chemical process is an excellent way of establishing nanomaterial decorated carbon materials for chemical sensor development in favor of detecting hazardous compounds in health-care and environmental fields at broad-scales. Finally, the efficiency of the proposed chemical sensors can be applied and utilized in effectively for the selective detection of toxic 2-NP component in environmental real samples with acceptable and reasonable results.

Preparation of gelatin based porous biocomposite for bone tissue engineering and evaluation of gamma irradiation effect on its properties

Biodegradable porous hybrid polymer composites were prepared by using gelatin as base polymer matrix, β-tricalcium phosphate (TCP) and calcium sulfate (CS) as cementing materials, chitosan as an antimicrobial agent, and glutaraldehyde and polyethylene glycol (PEG) as crosslinkers at different mass ratios. Thereafter, the composites were subjected to γ-radiation sterilization. The structure and properties of these composite scaffolds were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical properties testing (compressive, bending, tensile and impact), thermogravimetry/differential thermal analysis (TG/DTA), and physical stability test in simulated body fluid (SBF). We found that TCP rich composites showed enhanced mechanical properties among all the crosslinked composites. γ-Radiation sterilization triggered further cross linking in polymer matrix resulting a decrease in pore size of the composites and an increase in pore wall thickness with improved mechanical and thermal properties. The chemically crosslinked composite with 40% TCP followed by γ-radiation sterilization showed the smallest pore size distribution with a mean pore diameter of 159.22μm, which falls in the range of 100-350μm - known to be suitable for osteoconduction. Considering its improved mechanical and thermal properties along with osteoconduction ability without cytotoxicity, we propose this biocomposite as a viable candidate for bone tissue engineering.

Preparation and Characterization of Jute Cellulose Crystals-Reinforced Poly(L-lactic acid) Biocomposite for Biomedical Applications

Crystalline cellulose was extracted from jute by hydrolysis with 40% H2SO4 to get mixture of micro/nanocrystals. Scanning electron microscope (SEM) showed the microcrystalline structure of cellulose and XRD indicated the Iβ polymorph of cellulose. Biodegradable composites were prepared using crystalline cellulose (CC) of jute as the reinforcement (3–15%) and poly(lactic acid) (PLA) as a matrix by extrusion and hot press method. CC was cellulose derived from mercerized and bleached jute fiber by acid hydrolysis to remove the amorphous regions. FT-IR studies showed hydrogen bonding between the CC and the PLA matrix. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) studies showed that the percentage crystallinity of PLA in composites was found to be higher than that of neat PLA as a result of the nucleating ability of the crystalline cellulose. Furthermore, Vicker hardness and yield strength were found to increase with increasing cellulose content in the composite. The SEM images of the fracture surfaces of the composites were indicative of poor adhesion between the CC and the PLA matrix. The composite with 15% CC showed antibacterial effect though pure films but had no antimicrobial effect; on the other hand its cytotoxicity in biological medium was found to be medium which might be suitable for its potential biomedical applications.

Evaluation of Fat Binding Capacity of Gamma Irradiated Chitosan Extracted from Prawn Shell

We previously studied the effects of 2–100 kGy gamma radiation (generated from 6°Co) on physicochemical, thermal, morphological, and antimicrobial properties of chitosan. The results demonstrated that these properties of chitosan were largely influenced by the action of gamma radiation. In addition, the fat binding capacity (FBC) of chitosan was found to be increased with increasing irradiation doses. In this work a thorough in-vivo investigation on mice was performed to examine FBC of irradiated chitosan (30–100 kGy) in animal bodies. Different groups of mice specimens were fed with γ-irradiated chitosan along with natural rodent chow and cheese as well as sufficient supply of water. The unconsumed lipid measured in feces was found to increase by 67% in mice whose diet included 100 kGy irradiated chitosan, relative to that nonirradiated chitosan. After twelve weeks of intimate observation, mice were sacrificed to examine triglyceride (TG) and total cholesterol (TC) content in mice blood. The results demonstrated that TG and TC values of mice fed with γ-irradiated chitosan were significantly lower than that of the control. All of these findings are expected to enhance the future research on irradiated chitosan to be used as potential fat reducer in human metabolism.

Fabrication of 3-methoxyphenol sensor based on Fe 3 O 4 decorated carbon nanotube nanocomposites for environmental safety: Real sample analyses

Iron oxide ornamented carbon nanotube nanocomposites (Fe3O4.CNT NCs) were prepared by a wet-chemical process in basic means. The optical, morphological, and structural characterizations of Fe3O4.CNT NCs were performed using FTIR, UV/Vis., FESEM, TEM; XEDS, XPS, and XRD respectively. Flat GCE had been fabricated with a thin-layer of NCs using a coating binding agent. It was performed for the chemical sensor development by a dependable I-V technique. Among all interfering analytes, 3-methoxyphenol (3-MP) was selective towards the fabricated sensor. Increased electrochemical performances for example elevated sensitivity, linear dynamic range (LDR) and continuing steadiness towards selective 3-MP had been observed with chemical sensor. The calibration graph found linear (R2 = 0.9340) in a wide range of 3-MP concentration (90.0 pM ~ 90.0 mM). The limit of detection and sensitivity were considered as 1.0 pM and 9×10−4 μAμM-1cm-2 respectively. The prepared of Fe3O4.CNT NCs by a wet-chemical progression is an interesting route for the development of hazardous phenolic sensor based on nanocomposite materials. It is also recommended that 3-MP sensor is exhibited a promising performances based on Fe3O4.CNT NCs by a facile I-V method for the significant applications of toxic chemicals for the safety of environmental and health-care fields.

Micellization of Amphiphilic Drug with Pharmaceutical Excipients in Aqueous Electrolytic Solution: Composition, Interaction, and Stability of the Aggregates

In the present study, we report on the interaction between an antidepressant drug, amitriptyline hydrochloride, and nonionic surfactants (t-octylphenoxypolyethoxyethanol (TX-100), polyethoxyglycol t-octylphenyl ether (TX-114)), in aqueous electrolyte solutions, with special attention paid to the possible contribution from the ion–dipole type of interaction, by using a spectroscopic approach. The structural difference in the drug and nonionic surfactants also plays a role in tuning the aggregational behavior of the drug–surfactant mixtures. From the I 1/I 3 versus total surfactant concentration plots, the mixed critical micelle concentration (cmc) of various mixtures was computed. Critical assessments by applying Clint, Rubingh, and Motomura models confirm strong interactions in mixed micelle in the bulk of aqueous electrolytic solution. The various micellar parameters, such as micelle mole fraction ( ), interaction parameter (βm), micropolarity, and micelle aggregation number (N agg), have been determined for all different ratio mixtures. Micelle aggregation numbers (N agg) indicate that the contribution of nonionic surfactants was always more than that of the drug. Stern–Volmer binding constants (K sv) and dielectric constant of mixed systems have also been evaluated from the ratios of respective peak intensities (I 1/I 3 or I 0/I 1).

Preparation and characterization of poly (ethylene glycol) grafted Ca-alginate fibers by γ-irradiation for biomedical applications

Radiation processing, being a physical process, is an environmentally friendly alternative to chemical modifications. It is economically viable, safe, and possesses several advantages over other conventional methods employed for modification and grafting. To improve the physico-mechanical properties of Ca-alginate fiber (CaAF), poly (ethylene glycol) (PEG) was grafted by applying γ-radiation of different intensities. The effect of γ-irradiation on the physico-mechanical, thermal, morphological, thermal and water aging, water, and simulated body fluid (SBF) uptake were evaluated. FT-IR results confirmed that PEG was successfully grafted onto Ca-alginate fibers by γ-irradiation. From the detailed experimental results, irradiation doses and PEG concentration were optimized for grafting processes. The results showed that 50% PEG and 2.5 kGy irradiation dose yielded the highest tensile strength. Differential scanning calorimetric (DSC) analysis showed that with increasing γ-intensity a decrease of dehydration temperature of the fibers had occurred. On the other hand, the glass transition temperature (T g) increased with increasing irradiation dose. The tensile cracked surfaces of the grafted alginate fibers were analyzed by scanning electron microscope (SEM) in order to monitor their surface morphologies. The SEM images of the cracked surfaces demonstrated that spherical shape rods were present for irradiated fiber sample while no such rods were observed for non-irradiated fibers. The characteristic data obtained from SBF and water uptake, and water and thermal aging experiments indicated that CaAF grafted with 50% PEG by applying 2.5 kGy γ-irradiation can be potentially employed for biomedical purposes, such as surgical suture.

Mechanistic Investigation of Osmium(VIII) Catalyzed Oxidation of Glutamic Acid With Sodium Salt of N-Chloro 4-Methylbenzenesulfonamide in Aqueous Media: A Practical Approach

L-glutamic acid is used in the production of monosodium glutamate spices and other biochemical reagents. Its oxidation kinetics and a detailed mechanistic interaction of Os(VIII) catalyzed Glue-CAT reaction in alkaline medium have been investigated at different temperatures. It has been studied spectrophotometrically as a basic experimental approach for this study. All variables affecting the development of the color were investigated and the conditions were optimized. The effect of Glue, CAT, Os(VIII), and OH concentration on the rate of reaction has been studied. The reactions follow identical kinetics for all It is a first order reaction in both Glue and CAT, but fractional order in alkali and Os(VIII). Increasing ionic strength dielectric constant of the medium had no significant effect on the rate. The effects of added products like halide ions and toluene-p-sulfonamide have also been investigated. A mechanism involving the formation of a complex between Glue-CAT-Os(VIII) has been proposed. The stoichiometry of the reaction is found to be 1:1. The main products of Glue were identified with the help of FTIR and TLC. The reaction constants involved in the mechanism are explained. There is a good agreement between the observed and calculated rate constants under different experimental conditions. Investigations at different temperatures allowed the determination of the activation parameters with respect to the slow step of the proposed mechanism. The proposed methods were successfully applied for the high yield of the products and short reaction times. It is also an inexpensive, simple, and smooth method.