Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Molecularly imprinted polymer (MIP) for uric acid (UA) was synthesized by thermal polymerization using acrylic acid (AA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross linker and 2,2′-azobis(2-isobutyro) nitrile (AIBN) as initiator. The noncovalent interactions involved in four possible conformations of pre-polymer complex were computationally studied by density functional theory. The hydrogen bond formation between UA and AA was confirmed by Fourier transform infrared (FTIR) spectrum of the MIP before extraction of UA. After extraction of the template, the molecularly imprinted polymer based carbon paste electrode (MIPCPE) was fabricated under optimized conditions. A significant enhancement in the electrocatalytic oxidation of UA was found at MIPCPE. The electrochemical behavior of sensor was investigated by cyclic voltammetry (CV) and differential pulse adsorptive stripping voltammetry (DPAdSV). The electrochemical impedance spectroscopy (EIS) studies revealed less charge transfer resistance (Rct) at MIPCPE than NIPCPE. Under optimized conditions, calibration curve was obtained with a linearity range of 0.5μM to 100μM and the limit of detection was 0.1μM. The sensor showed good selectivity towards UA in the presence of interferents and was successfully applied for the determination of UA in spiked serum samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

World University root node

Chemistry

School of Advanced Sciences

Chennai Campus

Electroanalysis

Voltammetric Determination of Uric Acid Based on Molecularly Imprinted Polymer Modified Carbon Paste Electrode

Fulltext

Journal of Materials Research

Erratum: Engineered 2D nanomaterials-protein interfaces for efficient sensors (J. Mater. Res. (2015) DOI:10.1557/jmr.2015.349)

This paper presents the hardware implementation of 12/24V closed loop boost converter using dSPACE 1104 controller board for lamp load. The proposed system consists of 12V battery, closed loop boost converter and 24V lamp load. The closed loop boost converter is used to boost the 12V input DC voltage to 24V DC output. To regulate the output of the converter, feedback voltage is given to dSPACE controller. Using control desk and MATLAB, voltage from dSPACE is amplified and compared with reference voltage which in turn generates PWM signal that controls the switching of IGBT. Initially simulation is carried out using PI controller in MATLAB. The experimental results for closed loop boost converter obtained in software and hardware are presented here and verified with theoretical results. © 2014 IEEE.

VIT Unitversity

Language

School of Social Science and Languages

Department of Energy and Power Electronics

School of Electrical Engineering

Vellore Campus

2014 International Conference on Computation of Power, Energy, Information and Communication (ICCPEIC)

dSPACE based 12/24v closed loop boost converter for low power applications

Molecularly imprinted polymer (MIP) for sulfanilamide (SN) sensing is prepared through in-situ electropolymerization of pyrrole (Py) on pencil graphite electrode (PGE). Computational study using density functional theory with B3LYP level is performed to analyze and evaluate the template-monomer geometry. Among the various functional monomers studied pyrrole is found to have the highest binding interaction energy with SN and it is chosen as a functional monomer. Electropolymerization of pyrrole in the presence of SN on PGE is carried out using cyclic voltammetry. Structural morphology of the imprinted polymer is characterized by field emission scanning electron microscopy (FESEM) studies. Quantitative measurements of MIP based SN detection are performed by using cyclic voltammetry and differential pulse voltammetry studies. Several important kinetic parameters influencing the performance of SN sensor such as limit of detection, linear concentration range and sensitivity etc. are determined and analyzed. Under the optimized conditions, MIP based SN sensor proposed in this work has a very low detection limit of 2.0×10-8M (S/N=3) and possesses two linear ranges from 5.0×10-8 to 1.1×10-6M and 1.1×10-6 to 48×10-6M with a sensitivity value of 1.158 and 0.012μA/μM respectively. This particular sensor shows a good selectivity towards SN in presence of potential other structural analogue interferences namely sulfamethaxazole, sulfathiazole and sulfadiazine. Furthermore, the fabricated sensor is successfully applied to quantitatively determine and analyze SN present in spiked human serum and ground water samples. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemical Detection of Sulfanilamide Using Pencil Graphite Electrode Based on Molecular Imprinting Technology

In present paper experimental data on extractive desulfurization of liquid fuel using trihexyl tetradecyl phosphonium bis (2,4,4-trimethyl pentyl) phosphinate has been presented. The FTIR, 1H NMR, 13C NMR, 31P NMR, and ESR have been discussed for the molecular confirmation of synthesized phosphonium based ionic liquid. Further, conductivity, solubility, and viscosity analyses of phosphonium ionic liquids were carried out. The effects of reaction time, reaction temperature, sulfur compounds, ultrasonication, and recycling of ionic liquid without regeneration on removal of dibenzothiophene from liquid fuel were also investigated. In extractive desulfurization process, the removal of dibenzothiophene in n-dodecane was 79.5% for mass ratio of 1:1 in 30 min at 30 C under the mild reaction conditions. Phosphonium ionic liquids could be reused five times without a significant decrease in activity. Also, the desulfurization of real fuels, multistage extraction was examined. The data and results provided in present paper explore the significant insights of phosphonium based ionic liquids as novel extractant for extractive desulfurization of liquid fuels. © 2014 Published by Elsevier B.V.

Fuel Processing Technology

Synthesis, characterization, and application of novel trihexyl tetradecyl phosphonium bis (2,4,4-trimethylpentyl) phosphinate for extractive desulfurization of liquid fuel

Molecular imprinting technology is a convenient approach for preparing synthetic receptors that possesses user defined recognition properties. Oxalic acid imprinted bulk polymer was synthesized by thermal initiated free radical co-polymerization of oxalic acid (template) with two different functional monomers (acrylamide and methacrylic acid) and ethylene glycol dimethacrylate as crosslinker, using acetonitrile (porogen) as solvent. Scanning electron microscopy and FT-IR spectra confirmed the formation of molecularly imprinted polymer (MIP) with acrylamide. The synthesized MIP(ACR) efficiently adsorbed oxalic acid from aqueous solutions. The binding parameters of molecularly imprinted polymer and non-imprinted polymer were compared by Langmuir-Freundlich adsorption (LF) isotherm. © (2013) Trans Tech Publications, Switzerland.

Advanced Materials Research

Synthesis and evaluation of molecularly imprinted polymer for oxalic acid

Molecularly imprinted polymers (MIPs) are capable of recognizing a particular molecule in presence of others due to the selective cavities on it and thus are known as plastic antibodies. Pindolol (PDL) is a synthetic beta-adrenergic receptor blocking agent and widely used for the treatment of hypertension, cardiac arrhythmia and angina pectoris. Using a combinatorial method PDL imprinted polymers were prepared with three functional monomers viz., itaconic acid, 4-vinylpyridine and methacrylic acid by thermal initiated bulk polymerization technique using ethylene glycol dimethacrylate, 2, 2′-azobisisobutyronitrile and acetonitrile as crosslinker, initiator and solvent respectively. Among the three, PDL-itaconic acid MIP shows the best binding capacity. The PDL imprinted polymer was characterized by FTIR spectra and morphology was studied by SEM images. The binding parameters of MIP and non-imprinted polymer (NIP) were compared by the Freundlich and Langmuir adsorption isotherms. © 2013 Indian Institute of Metals.

Transactions of the Indian Institute of Metals

Synthesis and characterization of pindolol imprinted polymer

Computational approach plays an important role to pre-evaluate the interactions between template and functional monomer, so that to choose functional monomer having stronger interactions with template during synthesis of molecularly imprinted polymers (MIPs). Hence template-monomer interactions in pre-polymerization were mainly focused. In this paper, computational chemistry was applied to screen the number of mol of functional monomer that interacts with one mol of template. Intermolecular interactions between oxalic acid and acrylamide have been investigated. The binding energies ΔEbind were calculated by DFT (B3LYP) level of theory with the 6-31+G(d,p) basis set. It was found that four mol of acrylamide were sufficient to interact with one mol of oxalic acid in the pre-polymerization mixture. Four possible conformations and frequency calculations were performed to locate minima. Oxalic acid specific bulk polymer was obtained by the thermal initiated free radical co-polymerization of acrylamide and ethylene glycol dimethacrylate with oxalic acid as template and acetonitrile as porogen. The synthesized MIP efficiently adsorbed oxalic acid from aqueous solutions. The binding parameters of MIP and non-imprinted polymer (NIP) were compared by Freundlich and Langmuir adsorption isotherms. © 2013 Indian Academy of Sciences.

Journal of Chemical Sciences

Computational and experimental studies on oxalic acid imprinted polymer

This paper reports potentiometric determination of oxalic acid in spinach, using PVC-oxalic acid imprinted polymer coated graphite electrode. The intermolecular interactionsbetween oxalic acid and acrylamide functional monomer and the number of moles of functional monomer that interact with one mole of template were studied using computational method based on density functional theory. Oxalic acid specific bulk polymer was obtained by the thermal initiated free radical co-polymerization of acrylamide and ethylene glycol dimethacrylate with oxalic acid as template and acetonitrile as porogen. After extraction of template, the binding parameters of molecularly imprinted polymer (MIP) and non-imprinted polymer (NIP) were compared by Langmuir- Freundlich (L-F) adsorption isotherms. After optimization of membrane composition, electrode coated with MIP-PVC membrane in dioctyl phthalate as plasticizer, exhibited super Nernstian response (36.83 0.5 mV decade-1) over a concentration range of 1.0 10-7 to 1.0 10-2 M, with a low detection limit of 1.210-7 M. The sensor showed good selectivity and was successfully applied for determination of oxalic acid in spinach and ground water samples. © 2013 by ESG.

International Journal of Electrochemical Science

Potentiometric selective recognition of oxalic acid based on molecularly imprinted polymer

Pindolol (PDL) is a potent and specific adrenoreceptor blocking agent. It is widely used in the treatment of hypertension, cardiac arrhythmia and angina pectoris. Molecularly imprinted polymers (MIPs) are synthetic receptors having potential applications in drug delivery systems and devices such as diagnostic sensors. In the present work, ab initio quantum mechanical simulations and computational screening were used to identify functional monomer having best interactions with PDL. A virtual library of 16 functional monomers was built and the possible minimum energy conformation of the monomers and PDL were calculated using Hartree-Fock (HF) method for the synthesis of PDL imprinted polymer. The interaction energy between functional monomer and the template were corrected by means of basis set superposition error (BSSE) in all pre-polymerization complexes. The hydrogen bonding between PDL and functional monomer was evaluated by changes in bond lengths before and after complex formation. The virtual template-monomer complex with highest interaction energy is more stable during the polymerization and leads to high selectivity and specificity toward the template. The interaction energy of PDL was found to be the highest with itaconic acid followed by 4-vinyl pyridine and least with acrylonitrile. Taking a spectroscopic viewpoint, results obtained from analysis of the harmonic infrared spectrum were examined. Red and blue shifts related to the stretching frequencies of either donors or acceptors of protons were identified and compared experimentally. Stoichiometric mole ratio of template to functional monomer was optimized and confirmed by UV visible spectra titrations. The theoretical results were correlated by evaluation of binding parameters of MIPs. The experimental binding results were in good agreement with theoretical computations. © 2013 Springer-Verlag Berlin Heidelberg.