Publications by authors named "Rais A Khan"

Porous materials play a crucial role in the extraction of trace analytes; yet, the attainment of high selectivity and efficient regeneration continues to pose a considerable problem. In this study, we employed a green method to synthesize porous carbon microspheres. These microspheres were subsequently functionalized with aminophosphonic acid to facilitate the extraction of heavy metal ions from real samples.

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L-tryptophan is an amino acid that significantly impacts metabolic activity in both humans and herbivorous animals. It is also known as a precursor for melatonin and serotonin, and its levels must be regulated in the human body. Therefore, there is a need to develop a cost-effective, simple, sensitive, and selective method for detecting L-tryptophan.

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Three novel coordination polymers (CPs), namely [Cu(μ-1κO,2κN-L)] (1), [Zn (μ-1κO,2κN-L)(HO)] (2) and [Cd (μ-1κOO',2κN-L)] (3) [where HL = 4-(pyrimidin-5-ylcarbamoyl)benzoic acid], were synthesized and characterized by elemental analysis, ATR-IR, TGA, XPS and single-crystal X-ray diffraction. Despite having the same organic ligand, the various metal cations had an impact in the subsequent frameworks. Hirshfeld surface analysis was performed to investigate the intermolecular interactions and to examine the stability of the crystal structures of the three polymers.

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Hydrazine is considered a powerful reducing agent and catalyst, showing diverse applications in agricultural industries, toxic degradation research, and wastewater management. Additionally, hydrazine can trigger some specific reactions when combined with suitable oxidants. Due to its highly polar nature, hydrazine can easily dissolve in alcohol, water, and various other polar solvents.

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Graphitic carbon nitride nanosheets were synthesized onto cellulose nanofiber surfaces utilizing an eco-friendly salt melt approach. The fabricated material CNF@CN selectively removes Ni(II) and Cu(II) from electroplating wastewater samples. The immobilization of g-CN on solid substrates eases handling of nanomaterial in a flow-through approach and mitigates sorbent loss during column operations.

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In this study, we successfully synthesized polymeric graphitic carbon nitride (g-CN) nanosheets through thermal means and proposed their application in solid-phase extraction (SPE) for the enrichment of trace Hg(ii). The nanosheets underwent characterization using scanning electron microscopy, tunnelling electron microscopy, and energy-dispersive X-ray spectroscopy. The column packed with polymeric carbon nitride nanosheets demonstrated effective extraction of trace Hg(ii) ions from complex samples.

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The leaves of the Aegle marmelos plant were used for the green synthesis of copper oxide nanoparticles and further characterized by different techniques, including (Ultra Violet-Visible) UV-Vis, Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), Transmission electron microscopy (TEM) and X-ray diffraction (XRD). The UV-Vis showed a peak at 330 nm, which may be due to the Surface Plasmon Resonance phenomenon. XRD analysis showed the crystalline nature of copper oxide nanoparticles (CuO NPs).

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Azithromycin (AZY) is a well-known top-prioritized antibiotic and is used by humans in strong concentrations. However, the side effects of the AZY antibiotic may cause some serious and significant damage to humans and the environment. Thus, there is a need to develop effective and sensitive sensors to monitor accurate concentrations of AZY.

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L-tryptophan (L-TRP) is an essential amino acid responsible for the establishment and maintenance of a positive nitrogen equilibrium in the nutrition of human beings. Therefore, it is vital to quantify the amount of L-tryptophan in our body. Herein, we report the MoS/S@g-CN-modified glassy carbon electrode for the electrochemical detection of L-tryptophan (L-TRP).

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Iron-nickel bimetallic nanoparticles (Fe-Ni BMNPs) are prepared by combining two different metals by using the bottom-up approach. The resulting material has entirely different properties as compared to both the metals. The product is examined by using different analytical instruments such as.

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Recently, the simulation of perovskite solar cells (PSCs) via SCAPS-1D has been widely reported. In this study, we adopted SCAPS-1D as a simulation tool for the numerical simulation of lead-free (Pb-free) PSCs. We used methyl ammonium germanium iodide (MAGeI) as a light absorber, zinc oxysulphide (ZnOS) as an electron transport layer (ETL), and spiro-OMeTAD as a hole transport layer.

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Zirconium oxide (ZrO) nanoparticles were introduced onto cellulose nanofibers after being covalently functionalized with mercaptoacetic acid. We experimentally demonstrate that the nanocomposite is capable of selectively capturing Hg(ii) from aqueous samples down to trace level concentrations. Density functional theory (DFT) calculations indicate that energetically favorable R-S → Hg ← O-R bidentate complex formation enhances the rapid adsorption, leading to selective extraction of Hg(ii).

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The new 3D coordination polymer (CP) [Mn(L)(HCOO)] () [L = 4-(pyridin-4-ylcarbamoyl)benzoate] was synthesised via a hydrothermal reaction using the pyridyl amide functionalized benzoic acid HL. It was characterized by elemental, FT-IR spectroscopy, single-crystal and powder X-ray diffraction (PXRD) analyses. Its structural features were disclosed by single-crystal X-ray diffraction analysis, which revealed a 3D structure with the monoclinic space group P21/c.

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Serotonin is a very important monoamine neurotransmitter, which takes part in biological and psychological processes. In the present scenario, design and fabrication of a serotonin electrochemical sensor is of great significance. In this study, we have synthesized α-MnO via a hydrothermal synthesis method using potassium permanganate as a precursor.

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Hydroquinone is a widely used derivative of phenol which has a negative influence on human beings and the environment. The determination of the accurate amount of hydroquinone is of great importance. Recently, the fabrication of an electrochemical sensing device has received enormous attention.

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Recently, the design and fabrication of lead (Pb)-free perovskite or perovskite-like materials have received great interest for the development of perovskite solar cells (PSCs). Manganese (Mn) is a less toxic element, which may be an alternative to Pb. In this work, we explored the role of NH(CH)NHMnCl perovskite as a light absorber layer via SCAPS-1D.

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Carbon nanomaterials exhibit exceptional properties and broad horizon applications, where graphene is one of the most popular allotropes of this family due to its astounding performance in every stratum vis-à-vis other classical materials. The large surface area of 2630 m g, high electrical conductivity, and electron mobility of non-toxic graphene nanomaterials serve as the building blocks for supercapacitor studies. In this article, comparative studies are carried out between electrochemically exfoliated graphene sheets (GSs), solvothermally synthesized graphene quantum dots (GQDs) and acid refluxed carbon nanotubes (CNTs) as an energy storage electrode nanomaterial through cyclic voltammetry (CV).

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Lactoferrin is a heme-binding multifunctional glycoprotein known for iron transportation in the blood and also contributes to innate immunity. In this study, the interaction of theaflavin monogallate, a polyphenolic component of black tea, with camel milk lactoferrin was studied using various biophysical and computational techniques. Fluorescence quenching at different temperatures suggests that theaflavin monogallate interacted with lactoferrin by forming a non-fluorescent complex, , static quenching.

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Defect rich molybdenum disulfide (MoS) nanosheets were hydrothermally synthesized and their potential for ultrasound assisted dispersive solid phase microextraction of trace Hg(ii) ions was assessed. Ultrasonic dispersion allows the MoS nanosheets to chelate rapidly and evenly with Hg(ii) ions and results in improving the precision and minimizing the extraction time. The multiple defect rich surface was characterized by X-ray diffraction and high-resolution transmission electron microscopy.

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We report a graphene oxide (GO) lamellar membrane with increased inter-layer spacing for efficient permeation of water molecules and heavy metal ions through nanoporous graphene oxide. The inter-layer spacing of the GO sheets in the lamellar structure was increased by introducing poly-aminophosphonic acid (APA) in between the GO sheets. We demonstrate experimentally, the use of a prepared membrane (GO-APA) by a SPE technique for the preconcentration and extraction of heavy metal ions by chelate formation and their determination by ICP-OES.

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Metal ion extraction and determination at trace level concentration are challenging due to sample complexity or spectral interferences. Herein, we prepared a through-hole aluminum oxide membrane (AOM) by electrochemical anodization of aluminum substrates. The prepared AOM was characterized by scanning electron microscopy, surface area analysis, porosity measurements, and X-ray photoelectron spectroscopy.

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Quorum sensing (QS) and biofilm inhibition are recognized as the novel drug targets for the broad-spectrum anti-infective strategy to combat the infections caused by drug-resistant bacterial pathogens. Many compounds from medicinal plants have been found to demonstrate anti-infective activity. However, broad-spectrum anti-QS and antibiofilm efficacy and their mode of action are poorly studied.

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Biocompatible tryptophan-derived copper () and zinc () complexes with norharmane (β-carboline) were designed, synthesized, characterized, and evaluated for the potential anticancer activity in vitro and in vivo. The in vitro cytotoxicity of both complexes and were assessed against two cancerous cells: (human breast cancer) MCF7 and (liver hepatocellular cancer) HepG2 cells with a non-tumorigenic: (human embryonic kidney) HEK293 cells. The results exhibited a potentially decent selectivity of against MCF7 cells with an IC value of 7.

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Copper compounds are promising candidates for next-generation metal anticancer drugs. Therefore, we synthesized and characterized a formate bridged 1D coordination polymer [Cu(L)(HCOO)], (L = 2-methoxy-6-methyl-3-((quinolin-8-ylimino)methyl)chroman-4-ol), PCU1, wherein the Cu(ii) center adopts a square pyramidal coordination environment with adjacent CuCu distances of 5.28 Å.

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Herein, we report PAN-g-Alg@Ag-based nanocatalysts synthesis via in situ oxidative free-radical polymerization of acrylonitrile (AN) using Alg@Ag nanoparticles (Alg@Ag NPs). Various analytical techniques, including FTIR, XRD, SEM, TEM, UV-Vis, and DSC, were employed to determine bonding interactions and chemical characteristics of the nanocatalyst. The optimized response surface methodology coupled central composite design (RSM-CCD) reaction conditions were a 35-min irradiation time in a 70-mg L 2,4-dinitrophenol (DNP) solution at pH of 4.

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