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Vovusha, Hakkim
Publications (9 of 9) Show all publications
Hussain, T., Vovusha, H., Kaewmaraya, T., Amornkitbamrung, V. & Ahuja, R. (2018). Adsorption characteristics of DNA nucleobases, aromatic amino acids and heterocyclic molecules on silicene and germanene monolayers. Sensors and actuators. B, Chemical, 255, 2713-2720
Open this publication in new window or tab >>Adsorption characteristics of DNA nucleobases, aromatic amino acids and heterocyclic molecules on silicene and germanene monolayers
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2018 (English)In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 255, p. 2713-2720Article in journal (Refereed) Published
Abstract [en]

Binding of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules on two-dimensional silicene and germanene sheets have been investigated for the application of sensing of biomolecules using first principle density functional theory calculations. Binding energy range for nucleobases, amino acids and heterocyclic molecules with both the sheets have been found to be (0.43-1.16 eV), (0.70-1.58 eV) and (0.22-0.96 eV) respectively, which along with the binding distances show that these molecules bind to both sheets by physisorption and chemisorption process. The exchange of electric charges between the monolayers and the incident molecules has been examined by means of Bader charge analysis. It has been observed that the introduction of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules alters the electronic properties of both silicene and germanene nano sheets as studied by plotting the total (TDOS) and partial (PDOS) density of states. The DOS plots reveal the variation in the band gaps of both silicene and germanene caused by the introduction of studied molecules. Based on the obtained results we suggest that both silicene and germanene monolayers in their pristine form could be useful for sensing of biomolecules.

Keywords
Adsorption characteristics, DNA nucleobases, Aromatic amino acids, Heterocyclic molecules
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-341967 (URN)10.1016/j.snb.2017.09.083 (DOI)000414686500032 ()
Funder
Swedish Research CouncilCarl Tryggers foundation StandUp
Available from: 2018-02-19 Created: 2018-02-19 Last updated: 2018-02-19Bibliographically approved
Vovusha, H., Banerjee, D., Yadav, M. K., Perrozzi, F., Ottaviano, L., Sanyal, S. & Sanyal, B. (2018). Binding Characteristics of Anticancer Drug Doxorubicin with Two-Dimensional Graphene and Graphene Oxide: Insights from Density Functional Theory Calculations and Fluorescence Spectroscopy. The Journal of Physical Chemistry C, 122(36), 21031-21038
Open this publication in new window or tab >>Binding Characteristics of Anticancer Drug Doxorubicin with Two-Dimensional Graphene and Graphene Oxide: Insights from Density Functional Theory Calculations and Fluorescence Spectroscopy
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2018 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 36, p. 21031-21038Article in journal (Refereed) Published
Abstract [en]

There has been a perpetual interest in identifying suitable nano-carriers for drug delivery. In this regard, graphene-based two-dimensional materials have been proposed and demonstrated as drug carriers. In this paper, we have investigated the adsorption characteristics of a widely used anticancer drug, doxorubicin (DOX), on graphene (G) and graphene oxide (GO) by density functional theory calculations and fluorescence and X-ray photoelectron spectroscopies. From the calculated structural and electronic properties, we have concluded that G is a better binder of DOX compared to GO, which is also supported by our fluorescence measurements. The binding of DOX to G is mainly based on strong pi-pi stacking interactions. Consistent with this result, we also found that the sp(2) regions of GO interact with DOX stronger than the sp(3) regions attached with the functional groups; the binding is characterized by pi-pi and hydrogen-bonding interactions, respectively.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-366741 (URN)10.1021/acs.jpcc.8b04496 (DOI)000444920900049 ()
Funder
Swedish Research Council, 2016-05366Swedish Research Council, 20144423Swedish Research Council, 2017-05447Knut and Alice Wallenberg Foundation, KAW 2017.0055
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10Bibliographically approved
Haldar, S., Bhandary, S., Vovusha, H. & Sanyal, B. (2018). Comparative study of electronic and magnetic properties of iron and cobalt phthalocyanine molecules physisorbed on two-dimensional MoS2 and graphene. Physical Review B, 98(8), Article ID 085440.
Open this publication in new window or tab >>Comparative study of electronic and magnetic properties of iron and cobalt phthalocyanine molecules physisorbed on two-dimensional MoS2 and graphene
2018 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, no 8, article id 085440Article in journal (Refereed) Published
Abstract [en]

In this paper, we have done a comparative theoretical study of electronic and magnetic properties of iron phthalocyanine (FePc) and cobalt phthalocyanine (CoPc) molecules physisorbed on a monolayer of MoS2 and graphene by density functional theory. Various types of physisorption sites have been considered for both surfaces. The lowest energy structure for both metal phthalocyanine (MPc) molecules physisorbed on MoS2 is a sulfur-top position, i.e., when the metal center of the molecule is on top of a sulfur atom. However, on graphene, the lowest energy structure for the FePc molecule is when a metal atom is on top of a bridge position. In contrast to this, the CoPc molecule prefers a carbon-top position. The adsorption of MPc molecules is stronger on the MoS(2 )surface than on graphene (similar to 2.5 eV higher physisorption energy). In these systems, spin dipole moments of the metal centers are antiparallel to the spin moments and hence a huge reduction of effective spin moment can be seen. The calculations of magnetic anisotropy energies using both variational and second-order perturbation approaches indicate no significant changes after physisorption. In case of the FePc and CoPc physisorption, respectively, an out-of-plane and an in-plane easy axis of magnetization can be observed. Our calculations indicate a reduction of MoS2 work function similar to 1 eV due to physisorption of MPc molecules while it does not change significantly in the case of graphene.

National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-364179 (URN)10.1103/PhysRevB.98.085440 (DOI)000443395600008 ()
Funder
Swedish Research Council, 2017-05447
Available from: 2018-11-01 Created: 2018-11-01 Last updated: 2018-11-01Bibliographically approved
Vovusha, H., Amorim, R. G., Scheicher, R. H. & Sanyal, B. (2018). Controlling the orientation of nucleobases by dipole moment interaction with graphene/h-BN interfaces. RSC Advances, 8(12), 6527-6531
Open this publication in new window or tab >>Controlling the orientation of nucleobases by dipole moment interaction with graphene/h-BN interfaces
2018 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 8, no 12, p. 6527-6531Article in journal (Refereed) Published
Abstract [en]

The interfaces in 2D hybrids of graphene and h-BN provide interesting possibilities of adsorbing and manipulating atomic and molecular entities. In this paper, with the aid of density functional theory, we demonstrate the adsorption characteristics of DNA nucleobases at different interfaces of 2D hybrid nanoflakes of graphene and h-BN. The interfaces provide stronger binding to the nucleobases in comparison to pure graphene and h-BN nanoflakes. It is also revealed that the individual dipole moments of the nucleobases and nanoflakes dictate the orientation of the nucleobases at the interfaces of the hybrid structures. The results of our study point towards a possible route to selectively control the orientation of individual molecules in biosensors.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2018
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-347655 (URN)10.1039/c7ra11664k (DOI)000425034000041 ()
Funder
Knut and Alice Wallenberg FoundationSwedish Research CouncilCarl Tryggers foundation
Available from: 2018-04-06 Created: 2018-04-06 Last updated: 2018-04-06Bibliographically approved
Hussain, T., Kaewmaraya, T., Chakraborty, S., Vovusha, H., Amornkitbamrung, V. & Ahuja, R. (2018). Defected and Functionalized Germanene-based Nanosensors under Sulfur Comprising Gas Exposure. ACS SENSORS, 3(4), 867-874
Open this publication in new window or tab >>Defected and Functionalized Germanene-based Nanosensors under Sulfur Comprising Gas Exposure
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2018 (English)In: ACS SENSORS, ISSN 2379-3694, Vol. 3, no 4, p. 867-874Article in journal (Refereed) Published
Abstract [en]

Efficient sensing of sulfur containing toxic gases like H2S and SO2 is of the utmost importance due to the adverse effects of these noxious gases. Absence of an efficient 2D-based nanosensor capable of anchoring H2S and SO2 with feasible binding and an apparent variation in electronic properties upon the exposure of gas molecules has motivated us to explore the promise of a germanene nanosheet (Ge-NS) for this purpose. In the present study, we have performed a comprehensive computational investigation by means of DFT-based first-principles calculations to envisage the structural, electronic, and gas sensing properties of pristine, defected, and metal substituted Ge-NSs. Our initial screening has revealed that although interaction of SO2 with pristine Ge-NSs is within the desirable range, H2S binding however falls below the required values to guarantee an effective sensing. To improve the binding characteristics, we have considered the interactions between H2S and SO2 with defected and metal substituted Ge-NS. The systematic removals of Ge atoms from a reasonably large super cell lead to monovacancy, divacancies, and trivacancies in Ge-NS. Similarly, different transition metals like As, Co, Cu, Fe, Ga, Ge, Ni, and Zn have been substituted into the monolayer to realize substituted Ge-NS. Our van der Waals corrected DFT calculations have concluded that the vacancy and substitution defects not only improve the binding characteristics but also enhance the sensing propensity of both H2S and SO2. The total and projected density of states show significant variations in electronic properties of pristine and defected Ge-NSs before and after the exposure to the gases, which are essential in constituting a signal to be detected by the external circuit of the sensor. We strongly believe that our present work would not only advance the knowledge towards the application of Ge-NS-based sensing but also provide motivation for the synthesis of such efficient nanosensor for H2S and SO2 based on Ge monolayer.

Keywords
binding characteristics, nano sheets, substitution, nanostructures, nanosensors
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-355689 (URN)10.1021/acssensors.8b00167 (DOI)000431165200018 ()29582648 (PubMedID)
Funder
Swedish Research CouncilStandUpCarl Tryggers foundation
Available from: 2018-07-05 Created: 2018-07-05 Last updated: 2018-07-05Bibliographically approved
Hussain, T., Vovusha, H., Umer, R. & Ahuja, R. (2018). Superior sensing affinities of acetone towards vacancy induced and metallized ZnO monolayers. Applied Surface Science, 456, 711-716
Open this publication in new window or tab >>Superior sensing affinities of acetone towards vacancy induced and metallized ZnO monolayers
2018 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 456, p. 711-716Article in journal (Refereed) Published
Abstract [en]

The sensing propensities of acetone molecule towards zinc oxide monolayers (ZnO-ML) have been studied by means of density functional theory (DFT) calculations. Our van der Waals induced first principles calculations revealed that pristine ZnO-ML barely binds acetone, which limits its application as acetone sensing materials. However the formation of vacancies and foreign element doping improves acetone binding drastically. Among several defects, divacancy, and metal doping Li, Sc and Ti functionalization on ZnO-ML has been found the most promising ones. Presence of dangling electrons and partial positive charges in case of vacancy-induced and metallized ZnO-ML respectively, is believed to enhance the binding of acetone on the monolayers. The acetone-ZnO binding behavior has been further explained through studying the electronic properties by density of states and charge transfer mechanism though Bader analysis. Thus defected and metallized ZnO-ML could be a promising nano sensor for efficient sensing/capture of acetone.

Keywords
Monolayers, Adsorption, Formation energies, Defects, Electronic properties
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-362624 (URN)10.1016/j.apsusc.2018.06.155 (DOI)000441281300082 ()
Funder
Swedish Research CouncilStandUpCarl Tryggers foundation
Available from: 2018-10-08 Created: 2018-10-08 Last updated: 2018-10-08Bibliographically approved
Vovusha, H. & Sanyal, B. (2015). DFT and TD-DFT studies on the electronic and optical properties of explosive molecules adsorbed on boron nitride and graphene nano flakes. RSC Advances, 5(6), 4599-4608
Open this publication in new window or tab >>DFT and TD-DFT studies on the electronic and optical properties of explosive molecules adsorbed on boron nitride and graphene nano flakes
2015 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 6, p. 4599-4608Article in journal (Refereed) Published
Abstract [en]

The adsorption characteristics of explosive molecules: RDX, TATP, HMTD, TNT, HMX and PETN with boron nitride (BN) and graphene (G) flakes have been investigated using first principles density functional theory (DFT). It has been found that the binding between BN flakes and the explosive molecules is stronger than that with G flakes due to higher charge transfer in the BN-complexes. The energy decomposition analysis indicates that the dispersive interaction is the most dominant one. The optical properties and the nature of electronic transitions of BN and G-explosive complexes are studied by time dependent DFT (TD-DFT). It is observed that the strong interaction with BN flakes quenches the optical spectra by a significant amount whereas the graphene flakes leave the spectra almost unperturbed. Our findings of differential characteristics of 2D flakes will be useful for the designing of nanomaterials for the detection of aromatic and nonaromatic explosive molecules.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-241952 (URN)10.1039/c4ra11314d (DOI)000346570300086 ()
Available from: 2015-01-20 Created: 2015-01-19 Last updated: 2017-12-05Bibliographically approved
Banerjee, D., Vovusha, H., Pang, Y., Oumata, N., Sanyal, B. & Sanyal, S. (2014). Spectroscopic and DFT studies on 6-Aminophenanthridine and its derivatives provide insights in their activity towards ribosomal RNA. Biochimie, 97, 194-199
Open this publication in new window or tab >>Spectroscopic and DFT studies on 6-Aminophenanthridine and its derivatives provide insights in their activity towards ribosomal RNA
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2014 (English)In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 97, p. 194-199Article in journal (Refereed) Published
Abstract [en]

6-Aminophenanthridine (6AP), a plant alkaloid possessing antiprion activity, inhibits ribosomal RNA dependent protein folding activity of the ribosome (referred as PFAR). We have compared 6AP and its three derivatives 6AP8Cl, 6AP8CF3 and 6APi for their activity in inhibition of PFAR. Since PFAR inhibition requires 6AP and its derivatives to bind to the ribosomal RNA (rRNA), we have measured the binding affinity of these molecules to domain V of 23S rRNA using fluorescence spectroscopy. Our results show that similar to the antiprion activity, both the inhibition of PFAR and the affinity towards rRNA follow the order 6AP8CF3 > 6AP8Cl > 6AP, while 6APi is totally inactive. To have a molecular insight for the difference in activity despite similarities in structure, we have calculated the nucleus independent chemical shift using first principles density functional theory. The result suggests that the deviation of planarity in 6APi and steric hindrance from its bulky side chain are the probable reasons which prevent it from interacting with rRNA. Finally, we suggest a probable mode of action of 6AP, 6AP8CF3 and 6AP8Cl towards rRNA.

National Category
Natural Sciences
Research subject
Biochemistry; Physics with specialization in Biophysics
Identifiers
urn:nbn:se:uu:diva-218782 (URN)10.1016/j.biochi.2013.10.012 (DOI)000331410500022 ()24184272 (PubMedID)
Available from: 2014-02-17 Created: 2014-02-17 Last updated: 2017-12-06Bibliographically approved
Vovusha, H., Sanyal, S. & Sanyal, B. (2013). Interaction of Nucleobases and Aromatic Amino Acids with Graphene Oxide and Graphene Flakes. Journal of Physical Chemistry Letters, 4(21), 3710-3718
Open this publication in new window or tab >>Interaction of Nucleobases and Aromatic Amino Acids with Graphene Oxide and Graphene Flakes
2013 (English)In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 4, no 21, p. 3710-3718Article in journal (Refereed) Published
Abstract [en]

In this work, we have studied interactions of nucleobases and aromatic amino acids with graphene (G) and graphene oxide (GO) flakes by ab initio density functional theory (DFT). It is evident from the results that GO complexes are stabilized by hydrogen bonding interactions whereas G complexes are stabilized by pi-pi interactions, leading to enhanced binding energies for GO complexes compared to G complexes. Moreover, time-dependent DFT (TD-DFT) calculations for the optical properties reveal that the GO nanoflakes and GO-nucleobase composite absorb visible light in the range of 400-700 nm, which may be useful for light-emitting devices. The insights obtained from our study will be useful to understand the role of GO flakes as carriers in targeted drug delivery and biosensors.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-212315 (URN)10.1021/jz401929h (DOI)000326845200016 ()
Available from: 2013-12-10 Created: 2013-12-09 Last updated: 2017-12-06Bibliographically approved
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