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Author

Omprakash Nacham

Other affiliations: University of Toledo
Bio: Omprakash Nacham is an academic researcher from Iowa State University. The author has contributed to research in topics: Ionic liquid & Paramagnetism. The author has an hindex of 12, co-authored 17 publications receiving 686 citations. Previous affiliations of Omprakash Nacham include University of Toledo.

Papers
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Journal ArticleDOI
TL;DR: Hydrophobic magnetic ionic liquids (MILs) were synthesized and employed as solvents for the rapid and efficient extraction of DNA from aqueous solution, demonstrating the feasibility of MIL-based DNA sample preparation prior to downstream analysis.
Abstract: DNA extraction represents a significant bottleneck in nucleic acid analysis. In this study, hydrophobic magnetic ionic liquids (MILs) were synthesized and employed as solvents for the rapid and efficient extraction of DNA from aqueous solution. The DNA-enriched microdroplets were manipulated by application of a magnetic field. The three MILs examined in this study exhibited unique DNA extraction capabilities when applied toward a variety of DNA samples and matrices. High extraction efficiencies were obtained for smaller single-stranded and double-stranded DNA using the benzyltrioctylammonium bromotrichloroferrate(III) ([(C8)3BnN+][FeCl3Br–]) MIL, while the dicationic 1,12-di(3-hexadecylbenzimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide bromotrichloroferrate(III) ([(C16BnIM)2C122+][NTf2–, FeCl3Br–]) MIL produced higher extraction efficiencies for larger DNA molecules. The MIL-based method was also employed for the extraction of DNA from a complex matrix containing albumin, revealing a competitive...

172 citations

Journal ArticleDOI
TL;DR: The structural tunability and paramagnetic properties of MILs have enabled magnet-based technologies that can easily be added to the analytical method workflow, complement needed extraction requirements, or target specific analytes.

169 citations

Journal ArticleDOI
TL;DR: In this article, three general classes of hydrophobic ionic liquids including monocationic, symmetric/unsymmetrical dicationic, and symmetric and unsymmetric tricationic MILs were synthesized and characterized.
Abstract: Magnetic ionic liquids (MILs) are a subclass of ionic liquids (ILs) containing paramagnetic components and are readily manipulated by an external magnetic field. Due to their hydrophilic nature, very few applications of MILs in aqueous systems have been reported. In this study, three general classes of hydrophobic MILs including monocationic, symmetrical/unsymmetrical dicationic, and symmetrical/unsymmetrical tricationic MILs were synthesized and characterized. By tuning the structure of the MIL, various physicochemical properties including water solubility, magnetic susceptibility, and melting point were regulated. MILs synthesized with the benzimidazolium cation were shown to exhibit lower water solubility (0.1% (w/v)) when compared to those containing imidazolium cations (0.25% (w/v)). By incorporating asymmetry into the cationic component of the MIL, the melting point of dicationic MILs was lowered while the effective magnetic moment (μeff) and hydrophobicity remained unchanged. Tricationic MILs paire...

74 citations

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TL;DR: A simple, rapid method for MIL-based plasmid DNA extraction from crude bacterial cell lysate in which DNA-enriched MIL is transferred directly to a PCR tube for analysis.

71 citations

Journal ArticleDOI
TL;DR: In this paper, extremely hydrophobic ionic liquids (MILs) were synthesized by using transition and rare earth metal hexafluoroacetylacetonate chelated anions paired with the trihexyl(tetradecyl)phosphonium ([P66614+]) cation.
Abstract: Magnetic ionic liquids (MILs) are distinguished from traditional ionic liquids (ILs) by the incorporation of a paramagnetic component within their chemical structure. Hydrophobic MILs are novel solvents that can be used in many applications, including liquid–liquid extraction (LLE) and catalysis. Low viscosity and low water solubility are essential features that determine their feasibility in LLE. In this study, extremely hydrophobic MILs were synthesized by using transition and rare earth metal hexafluoroacetylacetonate chelated anions paired with the trihexyl(tetradecyl)phosphonium ([P66614+]) cation. Hydrophobic MILs exhibiting water solubilities less than 0.01% (v/v) were synthesized in a rapid two-step procedure. Furthermore, the viscosities of the MILs are among some of the lowest ever reported for hydrophobic MILs (276.5–927.9 centipoise (cP) at 23.7 °C) dramatically improving the ease of handling these liquids. For the first time, the magnetic properties of MILs possessing hexafluoroacetylacetonate chelated metal anions synthesized in this study are reported using a superconducting quantum interference device (SQUID) magnetometer. Effective magnetic moments (μeff) as high as 9.7 and 7.7 Bohr magnetons (μB) were achieved by incorporating high spin dysprosium and gadolinium ions, respectively, into the anion component of the MIL. The low viscosity, high hydrophobicity, and large magnetic susceptibility of these MILs make them highly attractive and promising solvents for separations and purification, liquid electrochromic materials, catalytic studies, as well as microfluidic applications.

61 citations


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TL;DR: The accumulated data on the biological activity of ionic liquids, including their antimicrobial and cytotoxic properties, are discussed in view of possible applications in drug synthesis and drug delivery systems.
Abstract: Ionic liquids are remarkable chemical compounds, which find applications in many areas of modern science. Because of their highly tunable nature and exceptional properties, ionic liquids have become essential players in the fields of synthesis and catalysis, extraction, electrochemistry, analytics, biotechnology, etc. Apart from physical and chemical features of ionic liquids, their high biological activity has been attracting significant attention from biochemists, ecologists, and medical scientists. This Review is dedicated to biological activities of ionic liquids, with a special emphasis on their potential employment in pharmaceutics and medicine. The accumulated data on the biological activity of ionic liquids, including their antimicrobial and cytotoxic properties, are discussed in view of possible applications in drug synthesis and drug delivery systems. Dedicated attention is given to a novel active pharmaceutical ingredient-ionic liquid (API-IL) concept, which suggests using traditional drugs in ...

1,065 citations

Journal ArticleDOI
TL;DR: The key accomplishments and future challenges to the field are discussed, with particular emphasis on the major lacunas found within the IL community dedicated to separation processes and by suggesting some steps to overcome the current limitations.
Abstract: Ionic liquids (ILs) have been proposed as promising media for the extraction and separation of bioactive compounds from the most diverse origins. This critical review offers a compilation on the main results achieved by the use of ionic-liquid-based processes in the extraction and separation/purification of a large range of bioactive compounds (including small organic extractable compounds from biomass, lipids, and other hydrophobic compounds, proteins, amino acids, nucleic acids, and pharmaceuticals). ILs have been studied as solvents, cosolvents, cosurfactants, electrolytes, and adjuvants, as well as used in the creation of IL-supported materials for separation purposes. The IL-based processes hitherto reported, such as IL-based solid–liquid extractions, IL-based liquid–liquid extractions, IL-modified materials, and IL-based crystallization approaches, are here reviewed and compared in terms of extraction and separation performance. The key accomplishments and future challenges to the field are discusse...

630 citations

01 Feb 2007
TL;DR: A review of magnetic particle-based methods for nucleic acid separation can be found in this paper, where the synthesis of a variety of magnetic particles is presented in more detail, as well as commercially available manual magnetic separators and automated systems for magnetic particle handling and liquid handling are mentioned.
Abstract: Nucleic acid separation is an increasingly important tool for molecular biology. Before modern technologies could be used, nucleic acid separation had been a time- and work-consuming process based on several extraction and centrifugation steps, often limited by small yields and low purities of the separation products, and not suited for automation and up-scaling. During the last few years, specifically functionalised magnetic particles were developed. Together with an appropriate buffer system, they allow for the quick and efficient purification directly after their extraction from crude cell extracts. Centrifugation steps were avoided. In addition, the new approach provided for an easy automation of the entire process and the isolation of nucleic acids from larger sample volumes. This review describes traditional methods and methods based on magnetic particles for nucleic acid purification. The synthesis of a variety of magnetic particles is presented in more detail. Various suppliers of magnetic particles for nucleic acid separation as well as suppliers offering particle-based kits for a variety of different sample materials are listed. Furthermore, commercially available manual magnetic separators and automated systems for magnetic particle handling and liquid handling are mentioned.

385 citations

Journal ArticleDOI
TL;DR: Application of main techniques widely used for preparation of a variety of coating materials of SPME, including sol-gel technique, electrochemical and electrospinning methods as well as the available commercial coatings, were presented and advantages and limitations of each technique were investigated.

234 citations

Journal ArticleDOI
TL;DR: In this article, the combined use of different types of ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) is described, such as META IL-DLME (magnetic effervescent tablet-assisted ionic Liquid- Liquid Micro Extraction), in-situ MR-IL-LME (in situ magnetic retrieval ionic-liqueficient liquid- liquid-extraction), and MIL-DTLME (MAGnetic ionic ionic liquids-based dispersive-liquid-microextraction) methods as well

226 citations