Dr. G H Pujar

Verified email at gmail.com

HoD-Physics
GM Institute of Technology, Davangere



                                   

https://researchid.co/puttpuja

Dr. GONIBASAPPA PUJAR
M.Sc., K-SET, Ph.D.(Physics)



Asst. Professor & Head, Controller of Examinations
Head of Research Centre (recognized by VTU, Belagavi), Department of Engineering Physics,
GM Institute of Technology, Davangere, Karnataka, India-577006
✉: puttpuja@gmail.com ☏: +91-9739136260
(Former Doctoral Research Scholar @ Centre for Advanced Studies and UGC-CPEPA, Département of Physics, Laser Spectroscopy Lab, Karnatak University, Dharwad-580003, Karnataka, India)


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ACADEMIA

2018
Doctor of Philosophy (Ph.D.) – Physics
Thesis Title:“Fluorescence Spectroscopic Study of Some Organic Compounds & Nanostructures”
Research Guide:

RESEARCH INTERESTS

 Material Science: Green synthesis-Nanoparticles, Synthesis, characterization and applications of Nanocellulose, Semiconducting Quantum dots and metallic nanoparticles (MNPs), Physical/analytical characterization-nanostructure materials, Characterization and applications of novel organic probes-na

FUTURE PROJECTS

Material Science-OLEDS

Photophysical/Optoelectronic properties, characterization of novel organic compounds and laser dyes, Energy Transfer studies in nanomaterial dispersed organic compounds & their possible role in emerging applications, Computational Physics (G09 Pro).


Applications Invited
Fabrication and sensing applications
26

Scopus Publications

207

Scholar Citations

9

Scholar h-index

9

Scholar i10-index

Scopus Publications

  • Facile green synthesis of ZnO-CuO nanocomposites using areca catechu leaves and their in vitro antidiabetic and cytotoxicity studies
    U R Shwetha, M S Latha, Virupaxappa S Betageri, G H Pujar, C R Rajith Kumar, M S Kiran, M S Sunita, Nagappa B Gokavi, and Shiva Prasad Kollur

    Advances in Natural Sciences: Nanoscience and Nanotechnology, eISSN: 20436262, Published: December 2021 IOP Publishing
    Abstract The fabrication and diverse applications of mixed oxides have received immense interest due to numerous prospects for better functional performance in tuning their properties compared to the basic metal oxides. Herein, we report synthesis of ZnO-CuO nanocomposites (NCs) using a simple and green route solution combustion method. The as-prepared ZnO-CuO NCs have been characterised through x-ray diffraction (XRD), energy dispersive x-ray (EDX) with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The results revealed that as-prepared ZnO-CuO NCs have spherical and rod-shaped structures with an average size between 10 and 30 nm. Further, ZnO-CuO NCs were tested for antidiabetic and anticancer properties. Amylase inhibition and MTT assays were carried out with different concentrations of NCs. The biological results depicted that the as-prepared nanocomposites exhibited significant cytotoxic effects with IC50 value of 13.29 μg mg−1. These observations further showed that the newly synthesised ZnO–CuO NCs are interesting and promising nanomaterials in pharmaceutical and healthcare sector.

  • Nanoparticle surface energy transfer (NSET) in ferroelectric liquid crystal-metallic-silver nanoparticle composites: Effect of dopant concentration on NSET parameters
    T. Vimal, G. H. Pujar, K Agrahari, Sanjeev R. Inamdar, and R. Manohar

    Physical Review E, ISSN: 24700045, eISSN: 24700053, Volume: 103, Published: February 2021 American Physical Society (APS)
    In the recent past, the resonance energy transfer studies using metallic nanoparticles has become a matter of quintessence in modern technology, which considerably extends its applications in probing specific biological and chemical processes. In the present study, metallic-silver nanoparticles of 2-4 nm (diameter) capped with hexanethiol ligand are developed and dispersed in ferroelectric liquid crystal (FLC). The morphology of nanoparticles was characterized using HR-TEM and SEM techniques. Furthermore, a systematic study of energy transfer between the host FLC material (as donors) and metallic-silver nanoparticles (as acceptors) has been explored employing steady state and time resolved fluorescence spectroscopic techniques. The nanoparticle based surface energy transfer (NSET) parameters viz., transfer efficiency, transfer rate, and proximity distance between donor and acceptor, have been determined for NSET couples (FLC material-metallic-silver nanoparticle) composites. It is observed that various NSET parameters and quenching efficiency follow a linear dependence on the concentration of metallic-silver nanoparticles in host FLC material. The nonradiative energy transfer and superquenching effect were analyzed with the help of Stern-Volmer plots. The impact of present study about superquenching effect of the silver nanoparticles can be used for sensing applications that require high degree sensitivity.

  • Facile Green Synthesis and Characterization of Moringa Oliefera Extract-Capped Silver Nanoparticles (MO-Agnps) and Its Biological Applications
    M S Kiran, M S Latha, Nagappa B Gokavi, G H Pujar, C R Rajith Kumar, U R Shwetha, and Virupaxappa S Betageri

    IOP Conference Series: Materials Science and Engineering, ISSN: 17578981, eISSN: 1757899X, Volume: 925, Published: 13 October 2020 IOP Publishing
    Abstract In the current study, we developed a simple, eco-friendly, quick and economical process to synthesize stable silver nanoparticles (AgNPs) using medicinal herb Moringa oliefera leaves extract. Obtained AgNPs are characterized by spectrophotometrical and microscopic techniques such as UV-Visible spectroscopy, x-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM). The study on the in vitro antidiabetic activities displayed that the particles have greater α-amylase inhibition potentials. In addition, exceptional antioxidant activity on 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) is observed. Cytotoxic study against Michigan Cancer Foundation-7 (MCF-7) cell lines displayed significant anticancer activity of AgNPs and hence they can be employed as a promising, cost-reliable and non-toxic strategy for treating these diseases in future.

  • Principal Component Analysis and its Application to Nominal Gross Domestic Product
    Suchitra Hiregowda, GH Pujar, and VS Betageri

    IOP Conference Series: Materials Science and Engineering, ISSN: 17578981, eISSN: 1757899X, Volume: 925, Published: 13 October 2020 IOP Publishing
    Abstract Gross Domestic Product refers to financial or market value of all goods and services which are produced within the countries in a specific time duration. As expansive measure of universal domestic production, it functions as a comprehensive record of the country’s economic health. Nominal Gross Domestic Product is the computation of raw data and is more utilitarian comparing national economies on the international market. Some countries have very differing Gross Domestic Product per capita between its regions. A countries region tend to intersect overtime, the discrepancy between the poorer and richer regions is kept over decades in other cases. Here, we considered progress in the nominal Gross Domestic Product per capita across 19 regions in Spain to provide the analysis of progress. This could answer few questions with respect to Nominal Gross Domestic Product viz., Have the regions converged? Which is the spread between regions? The central theme of this article is to answer whether can we make a cluster analysis of the regions after applying principal component analysis?

  • Nonlinear Radiative Heat Transfer of Magnetite(Fe<inf>3</inf>O<inf>4</inf>)-Water Nanofluid over Unsteady Stretching Surface with Fluid Particle Suspension
    N Srikantha, M R Krishnamurthy, M M Praveena, K S Onkarappa, K Bharathi, and G H Pujar

    IOP Conference Series: Materials Science and Engineering, ISSN: 17578981, eISSN: 1757899X, Volume: 925, Published: 13 October 2020 IOP Publishing
    Abstract The exploration of the magneto hydrodynamics(MHD) flow and nonlinear radiative heat transfer of magnetite Fe3O4 - H2O nanoparticle with fluid particle suspension over an unsteady stretching sheet is the central theme of the present work. The similarity transformations were employed to transfer the governing partial differential equations into ordinary ones prior to solve numerically using Runge - Kutta - Fehlberg-fourth and fifth order method with shooting technique. The variations of the temperature and velocity distribution and coefficients of heat transfer for magnetic parameter, temperature ratio parameter nanoparticle volume fraction, and thermal radiation parameter are discussed graphically. Comparative analysis of reported ones and present work results was presented and found to be in good agreement.

  • Hydroxy-benzimidazoles as blue-green emitters: Synthesis, structural and DFT studies
    Reshma Sathyanarayana, Vasantha Kumar, G.H. Pujar, Boja Poojary, Madan Kumar Shankar, and Sangappa Yallappa

    Journal of Photochemistry and Photobiology A: Chemistry, ISSN: 10106030, Volume: 401, Published: 1 October 2020 Elsevier BV
    Abstract The new benzimidazole ligands (3a-e) were synthesized using ethyl 4-(butylamino)-3-nitrobenzoate and substituted salicylaldehyde in the presence of sodium dithionite reagent which undergoes “one-pot’’ nitro reductive cyclization. Here benzimidazole moiety acts as an electron-acceptor (A) whereas substituted 2-hydroxyphenyl moiety acts as an electron-donor (D) unit. The molecular structures were characterised by FTIR, 1H NMR, 13C NMR, single crystal XRD and MS analysis. Optoelectronic properties were determined by UV–vis, solution and solid photoluminescence, quantum yield and lifetime. The solvent-dependent absorption and emission were studied using both polar protic and polar aprotic solvents. All the derivatives exhibited ESIPT, especially compound ethyl 1-butyl-2-(3,5-dichloro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (3e) displayed dual emission in both polar protic and polar aprotic solvents. The compound stability and electrochemical property were determined by thermal gravimetric analysis (TGA) and cyclic voltammetry (CV) respectively. The compounds emit intense blue-green fluorescence with high to moderate quantum yield. Also, these derivatives exhibited a high Stokes shift. The computational studies like Density-Functional Theory (DFT) and Molecular Electrostatic Potential (MEP) were conducted to provide important insights into the structure-property relationships. The crystal packing is stabilized through intermolecular hydrogen bonds (C---H…O) and intermolecular interactions (π… π). The findings of results help in developing novel ligands in the field of organic optoelectronics.

  • Hevea brasiliensis mediated synthesis of nanocellulose: Effect of preparation methods on morphology and properties
    H.S. Onkarappa, G.K. Prakash, G.H. Pujar, C.R. Rajith Kumar, M.S. Latha, and Virupaxappa S. Betageri

    International Journal of Biological Macromolecules, ISSN: 01418130, eISSN: 18790003, Volume: 160, Pages: 1021-1028, Published: 1 October 2020 Elsevier BV
    In present research, Hevea brasiliensis (Rubber Wood) converted into cellulose by pre-treatment with NaOH (5%) and NaClO2 (5%). In addition, the cellulose was converted to nanocellulose (NC) using ionic liquid, acid hydrolysis and TEMPO oxidation accompanied by ultra-sonication. The prepared nanocellulose was characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier transformation infrared spectroscopy (FT-IR). Thermal properties have been studied using thermogravimetric and differential thermal Analysis (TGA/DTA). FT-IR results clearly suggested that the synthetic approaches employed did not alter the principle chemical structure of rubber wood cellulose. SEM and AFM monographs reveal that synthetic approaches affect the morphology/surface topology of prepared nanocellulose. Among the three kinds of NC, NC by TEMPO approach had the largest aspect ratio and superior thermal stability.

  • Synthesis and characterization of nanocellulose using renewable resources through Ionic liquid medium
    Onkarappa H S, G K Prakash, G H Pujar, C R Rajith Kumar, Radha, M S Latha, and Virupaxappa S Betageri

    Advances in Natural Sciences: Nanoscience and Nanotechnology, eISSN: 20436262, Published: September 2020 IOP Publishing

  • Phase Contraction, fluorescence quenching and formation of topological defects in chiral smectic C matrix by Cd<inf>0.15</inf>Zn<inf>0.85</inf>S/ZnS core/shell quantum dots dispersion: Faster electro-optic response for gadget displays
    D. P. Singh, B. Duponchel, K. Kondratenko, Y. Boussoualem, G. H. Pujar, S. R. Inamdar, R. Douali, and A. Daoudi

    Liquid Crystals, ISSN: 02678292, eISSN: 13665855, Pages: 1638-1654, Published: September 2020 Informa UK Limited
    ABSTRACT Cd0.15Zn0.85S/ZnS core/shell quantum dots (CSQDs) of size 7.54 ± 0.99 nm in diameter were prepared via gram-scale one-pot synthesis method and dispersed in a ferroelectric liquid crystalline (FLC) material into two different concentrations. Spectroscopic, electro-optical (E-O) and morphological characterisations of aforementioned composites have been carried out. CSQDs cause a significant contraction in the width of chiral smectic C (SmC*) mesophase that has also been theoretically verified. Diffusion–controlled processes are responsible for the fluorescence quenching in the FLC/CSQDs composites which has been explained by using the Stern–Volmer quenching equation. The mesomorphic investigation has revealed that helical deformation takes place in the FLC/CSQDs composites, due to which the temperature-dependent gradual growth of ferroelectric domains is noticed. The perturbed helical geometry evinces a new structure-property correlation having a molecular switching time of 135 μs that is 51% faster response as compared to the pristine system. Resultant spontaneous polarisation in the matrix of FLC/CSQDs composites is diminished because of the induced homeotropic and flexoelectric contributions. The faster E-O response and optical imaging are the fascinating features of the FLC/CSQDs composites that can probably be utilised in gadget displays. Graphical abstract

  • One-Pot Synthesis of ZnO Nanoparticles for Nitrite Sensing, Photocatalytic and Antibacterial Studies
    C. R. Rajith Kumar, Virupaxappa S. Betageri, G. Nagaraju, B. P. Suma, M. S. Kiran, G. H. Pujar, and M. S. Latha

    Journal of Inorganic and Organometallic Polymers and Materials, ISSN: 15741443, eISSN: 15741451, Pages: 3476-3486, Published: 1 September 2020 Springer Science and Business Media LLC
    Abstract In this work, we have carried out an eco-friendly route for synthesis of zinc oxide nanoparticles (ZnO NPs) via solution combustion method using Calotropis gigantea leaves extract as fuel and Zn(NO 3 ) 2 ·6H 2 O as an oxidizer. The NPs had been characterized employing various analytical techniques namely XRD, SEM, EDAX, HR-TEM with SAED, FT-IR and UV-DRS. XRD confirms crystalline nature with average crystallite size of 31 nm. SEM and HR-TEM images shows that particles are in hexagonal and pyramidal shapes with particles size of 10–50 nm. In FT-IR, characteristic vibrational mode of NPs was observed at 442 cm −1 . The Optical energy band gap was found to be 3.25 eV. Considering practical applications, ZnO NPs exhibited superior photocatalytic activity for degradation of Methylene blue dye. Antibacterial activity of ZnO NPs was screened against Staphylococcus aureus and Escherichia coli bacterial strains. Further, electrochemical performance of developed sensor using NPs was investigated employing electrochemical approaches for quantification of nitrite. Graphic Abstract

  • Synthesis of Core/Shell (ZnO/Ag) Nanoparticles Using Calotropis gigantea and Their Applications in Photocatalytic and Antibacterial Studies
    C. R. Rajith Kumar, Virupaxappa S. Betageri, G. Nagaraju, G. H. Pujar, H. S. Onkarappa, and M. S. Latha

    Journal of Inorganic and Organometallic Polymers and Materials, ISSN: 15741443, eISSN: 15741451, Pages: 3410-3417, Published: 1 September 2020 Springer Science and Business Media LLC
    In this study, we have synthesized core/shell ZnO/Ag nanoparticles (NPs) via solution combustion method using Calotropis gigantea leaves extract as fuel and zinc nitrate hexahydrate Zn(NO)3·6H2O and silver nitrate AgNO3 as precursor. The prepared NPs were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX) and Fourier transform infrared (FT-IR). The optical energy band gap was studied using diffuse reflectance spectroscopy (DRS) and it is found to be 3.38 eV. ZnO/Ag NPs used as photocatalyst for degradation of methylene blue (MB) dye. Antibacterial activity for human pathogens (Escherichia coli and Staphylococcus aureus) studies through Agar well diffusion method.

  • Facile synthesis and characterization of nanocellulose from Zea mays husk
    H. S. Onkarappa, G. K. Prakash, G. H. Pujar, C. R. Rajith Kumar, Radha V, and Virupaxappa S. Betageri

    Polymer Composites, ISSN: 02728397, eISSN: 15480569, Pages: 3153-3159, Published: 1 August 2020 Wiley

  • Photocatalytic, nitrite sensing and antibacterial studies of facile bio-synthesized nickel oxide nanoparticles
    C.R. Rajith Kumar, Virupaxappa S. Betageri, G. Nagaraju, G.H. Pujar, B.P. Suma, and M.S. Latha

    Journal of Science: Advanced Materials and Devices, ISSN: 24682284, eISSN: 24682179, Pages: 48-55, Published: March 2020 Elsevier BV
    Abstract In the present work, Nickel oxide nanoparticles (NiO NPs) were synthesized using leaves extract of C. gigantea through a solution combustion method. The NiO NPs were characterized through analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The XRD results revealed rhombohedral structured crystallites with average size of 31 nm. SEM and TEM images indicate that the nanoparticles are agglomerated with an asymmetrical shape. The optical energy bandgap of 3.45 eV was estimated using UV-diffused reflectance spectroscopy (UV-DRS). The synthesized NiO NPs have shown superior photodegradation for methylene blue (MB) dye. Further, the antibacterial activity of the prepared nanoparticles was tested against E.coli and S.aureus bacterial strains. In addition, nanoparticles were utilized for electroanalytical applicability as a novel non-enzymatic sensor in the trace level quantification of nitrite. The proposed nitrite sensor showed wide linearity in the range 8–1700 μM and good stability with a lower detection limit of 1.2 μM.

  • One-pot green synthesis of ZnO-CuO nanocomposite and their enhanced photocatalytic and antibacterial activity
    C R Rajith Kumar, Virupaxappa S Betageri, G Nagaraju, G H Pujar, Onkarappa H S, and Latha M S

    Advances in Natural Sciences: Nanoscience and Nanotechnology, eISSN: 20436262, Published: 2020 IOP Publishing

  • Solvatochromism of a highly conjugated novel donor-π-acceptor dipolar fluorescent probe and its application in surface-energy transfer with gold nanoparticles
    G.H. Pujar, Narahari Deshapande, Imtiyaz Ahmed M. Khazi, and Sanjeev R. Inamdar

    Journal of Molecular Liquids, ISSN: 01677322, Volume: 271, Pages: 118-127, Published: 1 December 2018 Elsevier BV
    Abstract A novel highly conjugated donor-π-acceptor (D-π-A) fluorescent probe 4-((1E,3E)-4-(4-(5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl)phenyl)buta-1,3-dienyl)-N,N-dimethylbenzenamine (3TVPO) is synthesized using a Wittig reaction and characterized by 1H, 13C NMR, FT-IR spectroscopy and high-resolution mass spectrometry (HR-MS). The photophysical properties have been studied to understand the intramolecular charge-transfer (ICT) character of the compound. The solvatochromism of 3TVPO has been explored in polar protic/aprotic/weakly polar solvents. Various solvent correlation techniques such as Lippert–Mataga, Bilot–Kawski, Kawski–Chamma–Viallet, Bakhshiev, and Reichardt methods were employed to estimate the singlet ground- and excited-state dipole moment and are compared and discussed with those obtained computationally. The specific and non-specific solute-solvent interactions were analyzed using Kamlet–Taft and Catalan solvent parameters by means of a multiple-linear-regressions (MLR) method. In addition, surface-energy transfer (SET) has been studied using this optoelectronically important 3TVPO molecule as efficient donor and gold nanoparticles (Au MNPs) as excellent acceptors employing steady-state and time-resolved spectroscopic techniques. The size- and distance-dependent SET between 3TVPO and Au MNPs was explored. It is demonstrated that the quenching efficiency increases as the size of Au MNPs increases from 40 to 53 nm. The super-quenching effect and nonradiative energy transfer were analyzed using Stern–Volmer plots. The impact of the present investigation about the super-quenching effect of the Au MNPs can be exploited for biosensing applications owing to its acute sensitivity.

  • FRET from ZnSe/ZnS QDs to coumarin dyes: Role of acceptor dipole moment and QD surface states on FRET efficiency
    Sanjeev R. Inamdar, G.H. Pujar, and M.S. Sannaikar

    Journal of Luminescence, ISSN: 00222313, Volume: 203, Pages: 67-73, Published: November 2018 Elsevier BV
    Abstract Herein we report efficient fluorescence resonance energy transfer (FRET) between heavy metal free core-shell ZnSe/ZnS quantum dots (QDs as donors) and coumarin 540A (C540A), coumarin 515 (C515) and coumarin 519 (C519) laser dyes (as acceptors) using multiple spectroscopic techniques which interestingly provides a strong evidence for its dependence on acceptor dipole moment. The results also reveal that the coumarin dye acceptors, especially the C519 probe, significantly quench the photoluminescence intensity of QDs. Remarkably high energy transfer efficiencies ~ 85% in the QDs-C519 FRET pairs are noted which demonstrate that acceptor dipole moment could be associated with energy transfer via strong electrostatic dipole-dipole interaction. The FRET efficiency was investigated as function of QDs size and surface chemistry conditions. Interestingly, the nonlinear dependence of FRET efficiency on the spectral overlap was observed contradictory to the Forster's theory. This nonlinearity might be due to role of QDs surface states and acceptor dipole moment. The current work is not only expected to provide useful information about the interaction between inorganic and organic hetero-structured probes via FRET mechanism but also throws light on the role of acceptor dipole moment, surface states in addition to nonlinear dependence of transfer efficiency on spectral overlap.

  • Comprehensive study of interaction between biocompatible PEG-InP/ZnS QDs and bovine serum albumin
    M. S. Sannaikar, Laxmi S. Inamdar, G. H. Pujar, M. N. Wari, Nafisa H. Balasinor, and S. R. Inamdar

    Luminescence, ISSN: 15227235, eISSN: 15227243, Pages: 495-504, Published: May 2018 Wiley
    Polyethylene glycol (PEG) surface modified biocompatible InP/ZnS quantum dots (QDs) act as a potential alternative for conventional carcinogenic cadmium-based quantum dots for in vivo and in vitro studies. Comprehensively, we studied the interaction between a model protein bovine serum albumin (BSA) and PEGylated toxic free InP/ZnS QDs using various spectroscopic tools such as absorption, fluorescence quenching, time resolved and synchronous fluorescence spectroscopic measurements. These studies principally show that tryptophan (Trp) residues of BSA have preferable binding affinity towards PEG-InP/ZnS QDs surface and a blue shift in Trp fluorescence emission is a signature of conformational changes in its hydrophobic microenvironment. Photoluminescence (PL) intensity of Trp is quenched by ground state complex formation (static quenching) at room temperature. However, InP/ZnS@BSA conjugates become unstable with increasing temperature and PL intensity of Trp is quenched via dynamic quenching by PEG-InP/ZnS QDs. Experimentally determined thermodynamic parameters for these conjugates have shown spontaneity, entropy driven and exothermic nature of bio-conjugation. The calculated binding affinity (n ≅ 1, Hill coefficient) suggest that the affinity of InP/ZnS QDs for a BSA protein is not dependent on whether or not other BSA proteins are already bound to the QD surface. Energy transfer efficiency (E), Trp residue to InP/ZnS QDs distances and energy transfer rate (kT ) were all obtained from FÖrster resonance energy.

  • Synthesis, characterization and photophysical studies of zinc(II) complexes derived from a hydralazine hydrazone
    Sunil M. Patil, Ramesh S. Vadavi, Umashri Kendur, Geeta H. Chimmalagi, G.H. Pujar, Suresh D. Kulkarni, M. Nethaji, Sharanappa Nembenna, S.R. Inamdar, and Kalagouda B. Gudasi

    Journal of Photochemistry and Photobiology A: Chemistry, ISSN: 10106030, Volume: 351, Pages: 225-230, Published: 15 January 2018 Elsevier BV
    Abstract In the present study, we report two novel mononuclear zinc(II) complexes (1 and 2) obtained by reacting ( E )-1-(phenyl(pyridin-2-yl)methylene)-2-(phthalazin-1-yl)hydrazine (L) with ZnCl 2 and Zn(NO 3 ) 2 ∙6H 2 O respectively. Photophysical properties of the compounds were studied in both solution and solid phase. The fluorescence absolute quantum yield of the complexes in solution varies in the order 1 (0.01)

  • Dual photoluminescence and charge transport in an alkoxy biphenyl benzoate ferroelectric liquid crystalline-graphene oxide composite
    Dharmendra Pratap Singh, Benoit Duponchel, Yahia Boussoualem, Kaushlendra Agrahari, Rajiv Manohar, Veeresh Kumar, Renu Pasricha, Gonibasappa H. Pujar, Sanjeev R. Inamdar, Redouane Douali, and Abdelylah Daoudi

    New Journal of Chemistry, ISSN: 11440546, eISSN: 13699261, Pages: 16682-16693, Published: 2018 Royal Society of Chemistry (RSC)
    GO has been dispersed in a ferroelectric liquid crystalline material to prepare a FLC–GO composite.

  • Synthesis, photophysics of a novel green light emitting 1,3,4-oxadiazole and its application in FRET with ZnSe/ZnS QDs donor
    G.H. Pujar, Narahari Deshapande, M.S. Sannaikar, M.N. Wari, Imtiyaz Ahmed M. Khazi, and Sanjeev R. Inamdar

    Journal of Molecular Liquids, ISSN: 01677322, Volume: 248, Pages: 350-359, Published: December 2017 Elsevier BV
    Abstract The design and synthesis of a novel molecule 2-(4-((E)-2-(5-((E)-4-(5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl)styryl)thiophen-2-yl)vinyl)-5-(4-tert-butylphenyl)1,3,4-oxadiazole (2TVPO) based on Donor-π-Acceptor strategy through the Wittig reaction as well as characterization by 1H, 13C NMR spectroscopy, high resolution mass spectrometry and FT-IR spectroscopy form the central theme of the present work. Thermal (TGA and DSC), photophysical and electrochemical properties have been studied in detail for this novel probe. In addition, fluorescence resonance energy transfer (FRET) employing steady state and time resolved spectroscopy methods has been studied using core-shell ZnSe/ZnS QDs (7 and 8 nm) and 2TVPO fluorescent probe, respectively, as the energy donor and acceptor. Results of these studies reveal that (i) FRET pairs show a strong dipole-dipole interaction tendency to transfer energy from donor to acceptor; (ii) they possess high FRET efficiency and (iii) strong dependence of the acceptor emission on the overlap integral, quantum dot size and donor-acceptor distance. Further, the type of quenching is analyzed by Stern–Volmer plots.

  • A combined experimental and computational investigation of solvatochromism of nonpolar laser dyes: Evaluation of ground and singlet excited-state dipole moments
    G.H. Pujar, M.N. Wari, B. Steffi, H. Varsha, B. Kavita, C. Yohannan Panicker, C. Santhosh, Ajeetkumar Patil, and Sanjeev R. Inamdar

    Journal of Molecular Liquids, ISSN: 01677322, Volume: 244, Pages: 453-463, Published: October 2017 Elsevier BV
    Abstract In the present work, the solvatochromism of two large nonpolar laser dyes Exalite 384 (E384) and Exalite 416 (E416) has been studied both experimentally and computationally. The steady state absorption and fluorescence spectra have been measured in a series of polar protic, polar aprotic and non-polar/weakly polar solvents to investigate their solvatochromism and determine dipole moments. Various solvent correlation techniques, like Lippert–Mataga, Bilot–Kawski, Kawski–Chamma–Viallet, Bakhshiev and Reichardt methods were used to evaluate the singlet excited and ground state dipole moments. Kamlet–Taft and Catalan solvent parameters were used by means of multiple linear regression (MLR) method to analyze specific and non-specific solute-solvent interactions. Computational studies were carried out to optimize ground and excited state geometries using density functional theory (DFT) and time-dependent density functional theory (TD-DFT), respectively, in vacuum. This study also extends to evaluate the electronic transition energies from ground to first electronic excited state of solvated laser dyes employing semiempirical wave function model. In particular, the semiempirical method ZINDO has been combined with integral equation formalism of polarizable continuum model (IEF-PCM) to calculate solute-solvent interaction potential which is comparatively studied with E T (30) polarity scale along with experimental. The intramolecular charge transfer and hybridization is demonstrated by natural bond orbital analysis (NBO). The ground (μ g ) and excited state dipole moments (μ e ) of these dyes computed and those determined experimentally are compared and the results are discussed.

  • Time-resolved fluorescence and absence of Förster resonance energy transfer in ferroelectric liquid crystal-quantum dots composites
    D.P. Singh, S. Pandey, R. Manohar, S. Kumar, G.H. Pujar, and S.R. Inamdar

    Journal of Luminescence, ISSN: 00222313, Volume: 190, Pages: 161-170, Published: October 2017 Elsevier BV
    Abstract The present article deals with the interaction of octadecylamine (ODA) capped cadmium selenide quantum dots (CdSe QDs) and two ferroelectric liquid crystals (FLCs) having different values of spontaneous polarization (Ps). The pristine FLCs and FLC-QDs composites have been investigated by using steady-state and time-resolved fluorescence spectroscopic techniques. Stokes shift and the preferred alignment of FLC molecules in the presence of QDs are found to depend on the secondary order parameter of FLCs (i.e. Ps). The secondary fluorescence emissions have been strongly influenced by the concentration of QDs. The Forster resonance energy Transfer (FRET) was absent in both the composites. This article discloses the role of various factors, like relative orientation, dipolar interaction between donor and acceptor and the proximity of QDs (>10 nm), which might be responsible for the absence of FRET. FLC-QDs composites do not form a new class of luminescent material though the fluorescence properties of host FLCs are tailored in the presence of QDs by means of the change in molecular alignment. The change in lifetimes of FLC-QDs composites has not been observed.

  • Synthesis and Optoelectronic Exploration of Highly Conjugated 1,3,4-Oxadiazole Containing Donor-π-Acceptor Chromophores
    Narahari Deshapande, G. H. Pujar, Manjunath G. Sunagar, Supreet Gaonkar, Ningaraddi S. Belavagi, S. R. Inamdar, Chinna Bathula, and Imtiyaz Ahmed M. Khazi

    ChemistrySelect, eISSN: 23656549, Pages: 1793-1801, Published: 13 February 2017 Wiley

  • Synthesis, characterization and optoelectronic investigations of bithiophene substituted 1,3,4-oxadiazole derivatives as green fluorescent materials
    Narahari Deshapande, Ningaraddi S. Belavagi, Manjunath G. Sunagar, Supreet Gaonkar, G. H. Pujar, M. N. Wari, S. R. Inamdar, and Imtiyaz Ahmed M. Khazi

    RSC Advances, eISSN: 20462069, Issue: 105, Pages: 86685-86696, Published: 8 October 2015 Royal Society of Chemistry (RSC)
    Design and synthesis of novel bithiophene substituted oxadiazoles and exploration of their optoelectronic properties.

  • Design, synthesis and optoelectronic properties of unsymmetrical oxadiazole based indene substituted derivatives as deep blue fluoroscent materials
    Ningaraddi S. Belavagi, Narahari Deshapande, G. H. Pujar, M. N. Wari, S. R. Inamdar, and Imtiyaz Ahmed M. Khazi

    Journal of Fluorescence, ISSN: 10530509, Pages: 1323-1330, Published: 1 September 2015 Springer Science and Business Media LLC
    A series of novel unsymmetrically substituted indene-oxadiazole derivatives (3a–f) have been designed and synthesized by employing palladium catalysed Suzuki cross coupling reaction in high yields. The structural integrity of all the novel compounds was established by 1H, 13C NMR and LC/MS analysis. These compounds are amorphous in nature and are remarkably stable to long term storage under ambient conditions. The optoelectronic properties have been studied in detail using UV–Vis absorption and Fluorescence spectroscopy. All compounds emit intense blue to green-blue fluoroscence with high quantum yields. Time resolved measurments have shown life times in the range of 1.28 to 4.51 ns. The density functional theory (DFT) calculations were carried out for all the molecules to understand their structure–property relationships. Effect of concentration studies has been carried out in different concentrations for both absorption and emission properties and from this we have identified the optimized fluoroscence concentrations for all these compounds. The indene substituted anthracene-oxadiazole derivative (3f) showed significant red shift (λmaxemi = 490 nm) and emits intense green-blue fluoroscence with largest stokes shift of 145 nm. This compound also exhibited highest fluoroscence life time (τ) of 4.51 ns, which is very close to the standard dye coumarin-540A (4.63 ns) and better than fluorescein-548 (4.10 ns). The results demonstrated that the novel unsymmetrical indene-substituted oxadiazole derivatives could play important role in organic optoelectronic applications, such as organic light-emitting diodes (OLEDs) or as models for investigating the fluorescent structure–property relationship of the indene-functionalized oxadiazole derivatives.

RECENT SCHOLAR PUBLICATIONS

  • Facile green synthesis of ZnO–CuO nanocomposites using areca catechu leaves and their in vitro antidiabetic and cytotoxicity studies
    UR Shwetha, MS Latha, VS Betageri, GH Pujar, CRR Kumar, MS Kiran, ...
    Advances in Natural Sciences: Nanoscience and Nanotechnology 12 (4), 045011 2022

  • Nanoparticle surface energy transfer (NSET) in ferroelectric liquid crystal–metallic-silver nanoparticle composites: Effect of dopant concentration on NSET parameters
    T Vimal, GH Pujar, K Agrahari, SR Inamdar, R Manohar
    Physical Review E 103 (2), 022708 2021

  • Extraction of Nanocellulose for Futuristic Materials
    GHP Onkarappa H S , Radha V , Nikhileshwar V , Virupaxappa S Betageri ...
    Karnatak University Journal of Science 52, 1-13 2021

  • Nonlinear Radiative Heat Transfer of Magnetite(𝑭𝒆𝟑𝑶𝟒)- Water Nanofluid over Unsteady Stretching Surface with Fluid Particle Suspension
    GHP N Srikantha, MR Krishnamurthy, MM Praveena, KS Onkarappa, K Bharathi
    IOP Conf. Series: Materials Science and Engineering 925 (1), 012054 2020

  • Hydroxy-benzimidazoles as blue-green emitters: Synthesis, structural and DFT studies
    R Sathyanarayana, V Kumar, GH Pujar, B Poojary, MK Shankar, ...
    Journal of Photochemistry and Photobiology A: Chemistry 401, 112751 2020

  • Hevea brasiliensis mediated synthesis of nanocellulose: Effect of preparation methods on morphology and properties
    HS Onkarappa, GK Prakash, GH Pujar, CRR Kumar, MS Latha, ...
    International Journal of Biological Macromolecules 160, 1021-1028 2020

  • Facile Green Synthesis and Characterization of Moringa Oliefera Extract-Capped Silver Nanoparticles (MO-Agnps) And Its Biological Applications
    MS Kiran, MS Latha, NB Gokavi, GH Pujar, CRR Kumar, UR Shwetha, ...
    IOP Conference Series: Materials Science and Engineering 925 (1), 012055 2020

  • Principal Component Analysis and its Application to Nominal Gross Domestic Product
    S Hiregowda, GH Pujar, VS Betageri
    IOP Conference Series: Materials Science and Engineering 925 (1), 012012 2020

  • Phase Contraction, fluorescence quenching and formation of topological defects in chiral smectic C matrix by Cd0.15Zn0.85S/ZnS core/shell quantum dots
    DP Singh, B Duponchel, K Kondratenko, Y Boussoualem, GH Pujar, ...
    Liquid Crystals 47 (11), 1638-1654 2020

  • Synthesis of Core/Shell (ZnO/Ag) Nanoparticles Using Calotropis gigantea and Their Applications in Photocatalytic and Antibacterial Studies
    CR Rajith Kumar, VS Betageri, G Nagaraju, GH Pujar, HS Onkarappa, ...
    Journal of Inorganic and Organometallic Polymers and Materials 30 (9), 3410-3417 2020

  • Facile synthesis and characterization of nanocellulose from Zea mays husk
    HS Onkarappa, GK Prakash, GH Pujar, CR Rajith Kumar, VS Betageri
    Polymer Composites 41 (8), 3153-3159 2020

  • Synthesis and characterization of nanocellulose using renewable resources through Ionic liquid medium
    HS Onkarappa, GK Prakash, GH Pujar, CRR Kumar, MS Latha, ...
    Advances in Natural Sciences: Nanoscience and Nanotechnology 11 (3), 035001 2020

  • One-Pot Synthesis of ZnO Nanoparticles for Nitrite Sensing, Photocatalytic and Antibacterial Studies
    CRR Kumar, VS Betageri, G Nagaraju, BP Suma, MS Kiran, GH Pujar, ...
    Journal of Inorganic and Organometallic Polymers and Materials, 1-11 2020

  • One-pot green synthesis of ZnO–CuO nanocomposite and their enhanced photocatalytic and antibacterial activity
    CR Rajith Kumar, VS Betageri, G Nagaraju, GH Pujar, O HS, L MS
    Advances in Natural Sciences: Nanoscience and Nanotechnology 11 (1), 015009 2020

  • Photocatalytic, nitrite sensing and antibacterial studies of facile bio-synthesized nickel oxide nanoparticles
    CRR Kumar, VS Betageri, G Nagaraju, GH Pujar, BP Suma, MS Latha
    Journal of Science: Advanced Materials and Devices 5 (1), 48-55 2020

  • One-pot green synthesis of ZnO–CuO nanocomposite and their enhanced photocatalytic and antibacterial activity
    CRR Kumar, VS Betageri, G Nagaraju, GH Pujar, HS Onkarappa, ...
    Advances in Natural Sciences: Nanoscience and Nanotechnology 11 (1), 015009 2020

  • Text Book of Medicinal Chemistry: Biological importance of Medicinal plants
    GHP Latha M S, V S Betageri
    LAMBERT Academic Publishing 1, Paper back: 200 pages 2019

  • Solvatochromism of a highly conjugated novel donor-π-acceptor dipolar fluorescent probe and its application in surface-energy transfer with gold nanoparticles
    GH Pujar, N Deshapande, IAM Khazi, SR Inamdar
    Journal of Molecular Liquids 271, 118-127 2018

  • FRET from ZnSe/ZnS QDs to coumarin dyes: Role of acceptor dipole moment and QD surface states on FRET efficiency
    SR Inamdar, GH Pujar, MS Sannaikar
    Journal of Luminescence 2018

  • Comprehensive study of interaction between biocompatible PEG‐InP/ZnS QDs and bovine serum albumin
    MS Sannaikar, LS Inamdar, GH Pujar, MN Wari, NH Balasinor, ...
    Luminescence 33 (3), 495-504 2018

MOST CITED SCHOLAR PUBLICATIONS

  • Synthesis, characterization and optoelectronic investigations of bithiophene substituted 1, 3, 4-oxadiazole derivatives as green fluorescent materials
    N Deshapande, NS Belavagi, MG Sunagar, S Gaonkar, GH Pujar, ...
    RSC advances 5 (105), 86685-86696 2015
    Citations: 31

  • One-pot green synthesis of ZnO–CuO nanocomposite and their enhanced photocatalytic and antibacterial activity
    CRR Kumar, VS Betageri, G Nagaraju, GH Pujar, HS Onkarappa, ...
    Advances in Natural Sciences: Nanoscience and Nanotechnology 11 (1), 015009 2020
    Citations: 18

  • Photocatalytic, nitrite sensing and antibacterial studies of facile bio-synthesized nickel oxide nanoparticles
    CRR Kumar, VS Betageri, G Nagaraju, GH Pujar, BP Suma, MS Latha
    Journal of Science: Advanced Materials and Devices 5 (1), 48-55 2020
    Citations: 17

  • Dual photoluminescence and charge transport in an alkoxy biphenyl benzoate ferroelectric liquid crystalline–graphene oxide composite
    DP Singh, B Duponchel, Y Boussoualem, K Agrahari, R Manohar, ...
    New Journal of Chemistry 42 (20), 16682-16693 2018
    Citations: 16

  • Time-resolved fluorescence and absence of Frster resonance energy transfer in ferroelectric liquid crystal-quantum dots composites
    DP Singh, S Pandey, R Manohar, S Kumar, GH Pujar, SR Inamdar
    Journal of Luminescence 190, 161-170 2017
    Citations: 15

  • Design, synthesis and optoelectronic properties of unsymmetrical oxadiazole based indene substituted derivatives as deep blue fluoroscent materials
    NS Belavagi, N Deshapande, GH Pujar, MN Wari, SR Inamdar, IAM Khazi
    Journal of fluorescence 25 (5), 1323-1330 2015
    Citations: 13

  • Hevea brasiliensis mediated synthesis of nanocellulose: Effect of preparation methods on morphology and properties
    HS Onkarappa, GK Prakash, GH Pujar, CRR Kumar, MS Latha, ...
    International Journal of Biological Macromolecules 160, 1021-1028 2020
    Citations: 12

  • A combined experimental and computational investigation of solvatochromism of nonpolar laser dyes: Evaluation of ground and singlet excited-state dipole moments
    GH Pujar, MN Wari, B Steffi, H Varsha, B Kavita, CY Panicker, C Santhosh, ...
    Journal of Molecular Liquids 244, 453-463 2017
    Citations: 12

  • Synthesis, photophysics of a novel green light emitting 1,3,4-oxadiazole and its application in FRET with ZnSe/ZnS QDs donor
    ⁎ G.H. Pujar, Narahari Deshapande, M.S. Sannaikar, M.N. Wari, Imtiyaz Ahmed ...
    Journal of Molecular Liquids 248, 350-359 2017
    Citations: 12

  • Synthesis and Optoelectronic Exploration of Highly Conjugated 1, 3, 4‐Oxadiazole Containing Donor‐π‐Acceptor Chromophores
    N Deshapande, GH Pujar, MG Sunagar, S Gaonkar, NS Belavagi, ...
    ChemistrySelect 2 (5), 1793-1801 2017
    Citations: 9

  • Facile synthesis and characterization of nanocellulose from Zea mays husk
    HS Onkarappa, GK Prakash, GH Pujar, CR Rajith Kumar, VS Betageri
    Polymer Composites 41 (8), 3153-3159 2020
    Citations: 8

  • Phase Contraction, fluorescence quenching and formation of topological defects in chiral smectic C matrix by Cd0.15Zn0.85S/ZnS core/shell quantum dots
    DP Singh, B Duponchel, K Kondratenko, Y Boussoualem, GH Pujar, ...
    Liquid Crystals 47 (11), 1638-1654 2020
    Citations: 7

  • Synthesis of Core/Shell (ZnO/Ag) Nanoparticles Using Calotropis gigantea and Their Applications in Photocatalytic and Antibacterial Studies
    CR Rajith Kumar, VS Betageri, G Nagaraju, GH Pujar, HS Onkarappa, ...
    Journal of Inorganic and Organometallic Polymers and Materials 30 (9), 3410-3417 2020
    Citations: 7

  • Synthesis and characterization of nanocellulose using renewable resources through Ionic liquid medium
    HS Onkarappa, GK Prakash, GH Pujar, CRR Kumar, MS Latha, ...
    Advances in Natural Sciences: Nanoscience and Nanotechnology 11 (3), 035001 2020
    Citations: 6

  • FRET from ZnSe/ZnS QDs to coumarin dyes: Role of acceptor dipole moment and QD surface states on FRET efficiency
    SR Inamdar, GH Pujar, MS Sannaikar
    Journal of Luminescence 2018
    Citations: 6

  • Solvatochromism of a highly conjugated novel donor-π-acceptor dipolar fluorescent probe and its application in surface-energy transfer with gold nanoparticles
    GH Pujar, N Deshapande, IAM Khazi, SR Inamdar
    Journal of Molecular Liquids 271, 118-127 2018
    Citations: 4

  • Comprehensive study of interaction between biocompatible PEG‐InP/ZnS QDs and bovine serum albumin
    MS Sannaikar, LS Inamdar, GH Pujar, MN Wari, NH Balasinor, ...
    Luminescence 33 (3), 495-504 2018
    Citations: 3

  • Hydroxy-benzimidazoles as blue-green emitters: Synthesis, structural and DFT studies
    R Sathyanarayana, V Kumar, GH Pujar, B Poojary, MK Shankar, ...
    Journal of Photochemistry and Photobiology A: Chemistry 401, 112751 2020
    Citations: 2

  • One-Pot Synthesis of ZnO Nanoparticles for Nitrite Sensing, Photocatalytic and Antibacterial Studies
    CRR Kumar, VS Betageri, G Nagaraju, BP Suma, MS Kiran, GH Pujar, ...
    Journal of Inorganic and Organometallic Polymers and Materials, 1-11 2020
    Citations: 2

  • Synthesis, characterization and photophysical studies of zinc (II) complexes derived from a hydralazine hydrazone
    SM Patil, RS Vadavi, U Kendur, GH Chimmalagi, GH Pujar, SD Kulkarni, ...
    Journal of Photochemistry and Photobiology A: Chemistry 351, 225-230 2018
    Citations: 2

GRANT DETAILS

Areca Sheath: an Innovative Material for Acoustics and Noise Control” (Sanctioned ; 2020-21)

Mentors: Dr. Srinivasa CV, Dr. G H Pujar

Grant: Rs. 6000/- (Sanctioned under "Student Project Programme - 44th Series” by KCST, Govt. of Karnataka, India); Project Proposal Ref. No: 44S_BE_2571

RESEARCH OUTPUTS (PATENTS, SOFTWARE, PUBLICATIONS, PRODUCTS)

 Software/Tools/Applications: Gaussian 09 Pro, Originpro, FORTRAN pro, Mathcad, Mercury 3.8 pro, ChemSketch, Chemdraw, InkScape, DAS-6 Pro,

Operating Systems: DOS, Windows 98/XP, Windows Vista, Windows 7, 8, 8.1, 10, obuntu and MS Office, knowledge of formatting hard drives, installing Operating systems and softwares



Indian Patent (P. No.: 202141000258):
“Enhanced Storage Method of Gravitational Energy to Manage Renewable Resources” (2021)

Inventors: Gonibasappa Pujar, Santhosh B M, Prakash KK, et. al.,

Indian Patent (P. No.: 202041029920):
“Single Window Documentation for Multiple Assessment and Appraisal Requirements”

Inventors: Mouneshachari S, Rajakumar DG, H Gurumurthy, Naveen B, Nagendra HN, Gonibasappa Pujar, et. al.,


Indian Patent (P. No.:202011041959):
“IAIP-Interactive Business Data: Interactive Intelligent Business Data Visualization Using AI- Based Programming” (2020)

Inventors: Sandeep G, Vasudeva Nayaka KBL, Santhosh BM, Prakash KK, Prakash Chandra Behera, G H Pujar, et. al.,

Industry, Institute, or Organisation Collaboration

Sugar Industry, Shamanur Sugar Industry PVT. Ltd.

INDUSTRY EXPERIENCE

Distillery Industry, Shamanur Sugar Industry PVT. Ltd.