Photochemical modification of diamond was carried out by covalently bonding the radicals of 2-propanol-2-yl [(CH3)2C * OH] on the surface of diamond, which were produced by the photochemical disintegration of 2-hydroxy-2-methyl-1-phenyl-1-propanone irradiated by ultraviolet rays.A dispersion of diamond was prepared in acetone with the subsequent addition of 2-hydroxy-2-methyl-1-phenyl-1propanone which acted as photoinitiator.This mixture was put under irradiation with UV light for the generation of free radicals from 2-hydroxy-2-methyl-1-phenyl-1-propanone.These free radicals were introduced onto the surface of diamond and improved the dispersion in liquid phase.The modified diamond was characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, thermogravimetric analysis, thermogravimetric analysis-mass spectrometry and scanning electron microscopy.The scanning electron microscopy and dispersibility data demonstrated that the surface modification of diamond helped to improve its dispersibility in common organic solvents as well as the functional behaviour of its surface which may be useful in diagnosis/treatment of various diseases.
The detection of human serum albumin (HSA) is of significant clinical importance in disease diagnoses. In this work, polymer-based synthetic receptors are designed by incorporating Ag-ZnS microspheres in molecularly imprinted poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MIPs) for the gravimetric detection of HSA. Among different compositions of Ag-ZnS@MIPs, MIPs having methacrylic acid and ethylene glycol dimethacrylate volume ratio of 3:2 exhibit enhanced HSA sensitivity in the concentration range of 5–200 ng/mL. A remarkably low threshold limit of detection (LOD = 0.364 ng/mL) is achieved with quartz crystal microbalance (QCM) based gravimetric sensors. Furthermore, the Ag-ZnS@MIPs/QCM sensors show high selectivity for HSA compared to other proteins, e.g., bovine serum albumin (BSA), glycoprotein, ribonuclease, and lysozyme. Hence, the gravimetric quantification of HSA realizes a highly sensitive, selective, and label-free detection mechanism with a limit of quantification down to 1.1 ng/mL.
Modification of carbon nanotubes (CNTs) and their incoporation in polymer matrix have attracted much attention of researchers. As maximum dispersion of CNTs could enhance the properties of matrix dynamically, researchers are trying to find new methodologies to obtain this target. However, maximum dispersion remains a great challenge and under the stage of progress. Here, we claimed the synthesis of composites with a highly uniform dispersion of the filler that results significantly improved electrical features. In this regard, composites of polymethylmethacrylate (PMMA) were fabricated by using pristine and zwitterionic surfactant (ZIS) modified CNTs (ZIS-CNTs). Characterization was done by using ultraviolet–visible (UV–Vis), Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermo gravimetric analysis (TGA) techniques. UV–Vis and FTIR spectroscopy confirmed the synthesis of ZIS-CNTs and composites. UV–Vis spectra showed an increase in wavelength with the decrease in optical band gap for CNTs-based (CNTs/PMMA) and ZIS-CNTs-based (ZIS-CNTs/PMMA) composites. SEM and XRD studies confirmed a significant homogenoeus and uniform dispersion of CNTs in ZIS-CNTs/PMMA composites. An increase in conductivity of PMMA from 10−9 to 10−2 and 10−1 S/cm was observed on addition of less than 1% (mass fraction) of CNTs without and with modification by ZIS, respectively. Low values of percolation threshold at 0.5% and 0.005% for CNTs/PMMA and ZIS-CNTs/PMMA composites were obtained, respectively. TGA analysis showed a slow rate of decomposition for composites than that for pure PMMA. Around 600 °C, 3% CNTs/PMMA and 7% ZIS-CNTs/PMMA composites were left in the end, which depicts the increase in thermal stability of PMMA. This work depicts a better dispersion of CNTs in PMMA matrix via slight modification in synthesis as well as by using ZIS as surfactant.
The advancements in gas sensors application with maximum performances in selectivity, response, accuracy in resistance measurements and inexpensive fabrication cost has led researcher to develop and new outstand nanomaterials for environmental safety. In this study, we followed a simple hydrothermal route to synthesize ultrathin NiCo 2 O 4 nanosheets used in gas sensing applications. The wide surface area of nanosheets provides plenty of surface area for the adsorption of HCHO gas molecules. The nanostructures are testified using XRD, XPS, SEM and TEM, respectively. The nanosheets are tested for diverse gases at assorted effective temperature ranges, and shows high response and selectivity towards formaldehyde gas. The outstanding gas-sensing properties of ultrathin NiCo 2 O 4 nanosheets based sensor make it a potential candidate in industrial applications.
Natural product synthesis is an important area of chemical study having various prospects for medicinal, industrial, and agricultural industry. Grignard reaction was developed as a flexible and necessary tool for the production of complex organic compounds in synthetic procedures. Additionally, the synthetic flexibility of the Grignard reaction facilitates its usage in the construction of more complicated ring frameworks and stereoselective transformations. It has been substantially applied in natural product synthesis, demonstrating its effectiveness in the generation of crucial C-C, C-X bonds and the development of intricate molecular structures. Use of Grignard reaction has been significantly studied towards the synthesis of biologically active natural products such as terpenoids, polyketides, alkaloids and amino acids. This review outlines the numerous instances where Grignard reagents have been exploited in the synthesis of notable natural products since past two years.
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