Denzil Britto | University College Of Engineering Dindigul (original) (raw)

Papers by Denzil Britto

Research paper thumbnail of Anchoring of a nickel Schiff base complex with mixed ligands on MCM-41 as a heterogeneous catalyst for the synthesis of quinoxaline derivatives by various energies

Research paper thumbnail of A green one pot three component synthesis of tetrazole under microwave irradiation using Ni Schiff base complex of mixed ligands on MCM-41 as an efficient heterogeneous catalyst

Syntheses of 5-substituted tetrazole derivatives have been reported by one-pot three-component re... more Syntheses of 5-substituted tetrazole derivatives have been reported by one-pot three-component reaction of various aldehydes (aryl, aryl with fused ring, aryl with extended conjugation, heterocyclic and aliphatic), hydroxylamine hydrochloride and sodium azide in the presence of potent, reusable, low cost and thermally stable catalyst, Ni-complex MCM-41 under conventional heating / microwave irradiation. The prepared materials were characterized by FT-IR, PXRD analysis, N 2 adsorption and desorption, EDX, SEM and TEM microscopy, ICP-OES and TGA. The effect of solvent, temperature, catalyst loading and time for the syntheses of tetrazoles were optimized. The e ciency of Ni-MCM-41 catalyst is compared and discussed against the literature reports. The catalyst can be successively recovered by simple ltration method and reused upto ve times with excellent yields upto 94%. In general, microwave irradiation technique gave better yields when compared to conventional heating irrespective of the nature of the substrate and their substituents.

Research paper thumbnail of Carbazole-azine based fluorescence 'off-on' sensor for selective detection of Cu(2+) and its live cell imaging

Luminescence : the journal of biological and chemical luminescence, Jan 20, 2017

A new carbazole-azine based fluorescent sensor was synthesized and characterized. The selectivity... more A new carbazole-azine based fluorescent sensor was synthesized and characterized. The selectivity of the sensor for Cu(2+) over other counter ions in a dimethyl sulfoxide/H2 O mixture was shown through enhancement in fluorescence - an off to on transformation. The specificity of the probe towards Cu(2+) was evident in ultraviolet/visible, fluorescence, Fourier transform infrared and mass studies. Application of the probe in the cell imaging and cytotoxicity of living cells is illustrated.

Research paper thumbnail of Phenothiazine-diaminomalenonitrile based Colorimetric and Fluorescence “Turn-off-on” Sensing of Hg2+ and S2−

Sensors and Actuators B: Chemical, 2016

Abstract In this paper a novel, easily available, “on-off-on” fluorescent and colorimetric probe ... more Abstract In this paper a novel, easily available, “on-off-on” fluorescent and colorimetric probe based on Phenothiazine was synthesized and characterized by 1 H NMR, 13 C NMR and ESI–MS. Results showed selective and sensitive recognition towards Hg 2+ and S 2− with no significant interference with other competitive metal ions and anions. The detection limit of Hg 2+ was found to be 17.8 nM. Furthermore the probe has been utilized for fluorescence imaging of Hg 2+ in live cells.

Research paper thumbnail of Fluorescence “on–off–on” chemosensor for selective detection of Hg2+ and S2−: application to bioimaging in living cells

RSC Advances, 2016

A phenothiazine based diamino-malenonitrile-linked (P-1) chromogenic and fluorogenic probe was sy... more A phenothiazine based diamino-malenonitrile-linked (P-1) chromogenic and fluorogenic probe was synthesized and characterized for the specific detection of Hg2+ and S2−. The probe P-1 can be used for selective imaging of Hg2+ and S2− in living cells.

Research paper thumbnail of Phenothiazine based sensor for naked-eye detection and bioimaging of Hg(ii) and F− ions

RSC Advances, 2015

The design and development of new phenothiazine-based fluorescent probes, which displays selectiv... more The design and development of new phenothiazine-based fluorescent probes, which displays selective fluorescence response to Hg2+ and F− ions in a reversible manner. The probe is the first example that facilitates the detection of Hg2+ at nanomolar concentration.

Research paper thumbnail of Anchoring of a nickel Schiff base complex with mixed ligands on MCM-41 as a heterogeneous catalyst for the synthesis of quinoxaline derivatives by various energies

Research paper thumbnail of Unique carbazole – N,N-dimethylanline linked chalcone a colorimetric and fluorescent probe for picric acid explosive and its test strip analysis

Journal of Photochemistry and Photobiology A: Chemistry

Research paper thumbnail of Carbazole–azine based fluorescence 'off–on' sensor for selective detection of Cu 2+ and its live cell imaging

A new carbazole–azine based fluorescent sensor was synthesized and characterized. The selec-tivit... more A new carbazole–azine based fluorescent sensor was synthesized and characterized. The selec-tivity of the sensor for Cu 2+ over other counter ions in a dimethyl sulfoxide/H 2 O mixture was shown through enhancement in fluorescence – an off to on transformation. The specificity of the probe towards Cu 2+ was evident in ultraviolet/visible, fluorescence, Fourier transform infra-red and mass studies. Application of the probe in the cell imaging and cytotoxicity of living cells is illustrated.

Research paper thumbnail of Phenothiazine-diaminomalenonitrile based Colorimetric and Fluorescence " Turn-off-on " Sensing of Hg 2+ and S 2-

In this paper a novel, easily available, " on-off-on " fluorescent and colorimetric probe based o... more In this paper a novel, easily available, " on-off-on " fluorescent and colorimetric probe based on Phenoth-iazine was synthesized and characterized by 1 H NMR, 13 C NMR and ESI–MS. Results showed selective and sensitive recognition towards Hg 2+ and S 2− with no significant interference with other competitive metal ions and anions. The detection limit of Hg 2+ was found to be 17.8 nM. Furthermore the probe has been utilized for fluorescence imaging of Hg 2+ in live cells.

Research paper thumbnail of Fluorescence " on–off–on " chemosensor for selective detection of Hg 2+ and S 2- : application to bioimaging in living cells

A phenothiazine based diamino-malenonitrile-linked chromogenic and fluorogenic probe (P-1) was sy... more A phenothiazine based diamino-malenonitrile-linked chromogenic and fluorogenic probe (P-1) was synthesized and characterized for the specific detection of Hg 2+ and S 2À. In the presence of Hg 2+ , the probe produces " switch-off " along with a color change from yellow to brown, allowing colorimetric detection of Hg 2+ by the naked eye. The sensitivity of probe P-1 towards Hg 2+ and S 2À was demonstrated in living cells, and cell toxicity assay also reveals that the probe P-1 can be used for selective imaging of Hg 2+ and S 2À in living cells.

Research paper thumbnail of Phenothiazine based sensor for naked-eye detection and bioimaging of Hg(II) and F- ions

The design and development of new phenothiazine-based fluorescent probes, which display a selecti... more The design and development of new phenothiazine-based fluorescent probes, which display a selective fluorescence response to mercury and fluoride ions, were described. The probe is the first example that facilitates the detection of Hg 2+ at nanomolar concentrations. The sensitivity of probe P-1 to Hg 2+ and F À was demonstrated in living cells, and cell toxicity assays revealed that probe P-1 can be used for selective imaging of Hg 2+ and F À in living cells. Moreover, the simple probe design presented here may contribute to the development of more efficient and more useful dual-mode probes.

Research paper thumbnail of Anchoring of a nickel Schiff base complex with mixed ligands on MCM-41 as a heterogeneous catalyst for the synthesis of quinoxaline derivatives by various energies

Research paper thumbnail of A green one pot three component synthesis of tetrazole under microwave irradiation using Ni Schiff base complex of mixed ligands on MCM-41 as an efficient heterogeneous catalyst

Syntheses of 5-substituted tetrazole derivatives have been reported by one-pot three-component re... more Syntheses of 5-substituted tetrazole derivatives have been reported by one-pot three-component reaction of various aldehydes (aryl, aryl with fused ring, aryl with extended conjugation, heterocyclic and aliphatic), hydroxylamine hydrochloride and sodium azide in the presence of potent, reusable, low cost and thermally stable catalyst, Ni-complex MCM-41 under conventional heating / microwave irradiation. The prepared materials were characterized by FT-IR, PXRD analysis, N 2 adsorption and desorption, EDX, SEM and TEM microscopy, ICP-OES and TGA. The effect of solvent, temperature, catalyst loading and time for the syntheses of tetrazoles were optimized. The e ciency of Ni-MCM-41 catalyst is compared and discussed against the literature reports. The catalyst can be successively recovered by simple ltration method and reused upto ve times with excellent yields upto 94%. In general, microwave irradiation technique gave better yields when compared to conventional heating irrespective of the nature of the substrate and their substituents.

Research paper thumbnail of Carbazole-azine based fluorescence 'off-on' sensor for selective detection of Cu(2+) and its live cell imaging

Luminescence : the journal of biological and chemical luminescence, Jan 20, 2017

A new carbazole-azine based fluorescent sensor was synthesized and characterized. The selectivity... more A new carbazole-azine based fluorescent sensor was synthesized and characterized. The selectivity of the sensor for Cu(2+) over other counter ions in a dimethyl sulfoxide/H2 O mixture was shown through enhancement in fluorescence - an off to on transformation. The specificity of the probe towards Cu(2+) was evident in ultraviolet/visible, fluorescence, Fourier transform infrared and mass studies. Application of the probe in the cell imaging and cytotoxicity of living cells is illustrated.

Research paper thumbnail of Phenothiazine-diaminomalenonitrile based Colorimetric and Fluorescence “Turn-off-on” Sensing of Hg2+ and S2−

Sensors and Actuators B: Chemical, 2016

Abstract In this paper a novel, easily available, “on-off-on” fluorescent and colorimetric probe ... more Abstract In this paper a novel, easily available, “on-off-on” fluorescent and colorimetric probe based on Phenothiazine was synthesized and characterized by 1 H NMR, 13 C NMR and ESI–MS. Results showed selective and sensitive recognition towards Hg 2+ and S 2− with no significant interference with other competitive metal ions and anions. The detection limit of Hg 2+ was found to be 17.8 nM. Furthermore the probe has been utilized for fluorescence imaging of Hg 2+ in live cells.

Research paper thumbnail of Fluorescence “on–off–on” chemosensor for selective detection of Hg2+ and S2−: application to bioimaging in living cells

RSC Advances, 2016

A phenothiazine based diamino-malenonitrile-linked (P-1) chromogenic and fluorogenic probe was sy... more A phenothiazine based diamino-malenonitrile-linked (P-1) chromogenic and fluorogenic probe was synthesized and characterized for the specific detection of Hg2+ and S2−. The probe P-1 can be used for selective imaging of Hg2+ and S2− in living cells.

Research paper thumbnail of Phenothiazine based sensor for naked-eye detection and bioimaging of Hg(ii) and F− ions

RSC Advances, 2015

The design and development of new phenothiazine-based fluorescent probes, which displays selectiv... more The design and development of new phenothiazine-based fluorescent probes, which displays selective fluorescence response to Hg2+ and F− ions in a reversible manner. The probe is the first example that facilitates the detection of Hg2+ at nanomolar concentration.

Research paper thumbnail of Anchoring of a nickel Schiff base complex with mixed ligands on MCM-41 as a heterogeneous catalyst for the synthesis of quinoxaline derivatives by various energies

Research paper thumbnail of Unique carbazole – N,N-dimethylanline linked chalcone a colorimetric and fluorescent probe for picric acid explosive and its test strip analysis

Journal of Photochemistry and Photobiology A: Chemistry

Research paper thumbnail of Carbazole–azine based fluorescence 'off–on' sensor for selective detection of Cu 2+ and its live cell imaging

A new carbazole–azine based fluorescent sensor was synthesized and characterized. The selec-tivit... more A new carbazole–azine based fluorescent sensor was synthesized and characterized. The selec-tivity of the sensor for Cu 2+ over other counter ions in a dimethyl sulfoxide/H 2 O mixture was shown through enhancement in fluorescence – an off to on transformation. The specificity of the probe towards Cu 2+ was evident in ultraviolet/visible, fluorescence, Fourier transform infra-red and mass studies. Application of the probe in the cell imaging and cytotoxicity of living cells is illustrated.

Research paper thumbnail of Phenothiazine-diaminomalenonitrile based Colorimetric and Fluorescence " Turn-off-on " Sensing of Hg 2+ and S 2-

In this paper a novel, easily available, " on-off-on " fluorescent and colorimetric probe based o... more In this paper a novel, easily available, " on-off-on " fluorescent and colorimetric probe based on Phenoth-iazine was synthesized and characterized by 1 H NMR, 13 C NMR and ESI–MS. Results showed selective and sensitive recognition towards Hg 2+ and S 2− with no significant interference with other competitive metal ions and anions. The detection limit of Hg 2+ was found to be 17.8 nM. Furthermore the probe has been utilized for fluorescence imaging of Hg 2+ in live cells.

Research paper thumbnail of Fluorescence " on–off–on " chemosensor for selective detection of Hg 2+ and S 2- : application to bioimaging in living cells

A phenothiazine based diamino-malenonitrile-linked chromogenic and fluorogenic probe (P-1) was sy... more A phenothiazine based diamino-malenonitrile-linked chromogenic and fluorogenic probe (P-1) was synthesized and characterized for the specific detection of Hg 2+ and S 2À. In the presence of Hg 2+ , the probe produces " switch-off " along with a color change from yellow to brown, allowing colorimetric detection of Hg 2+ by the naked eye. The sensitivity of probe P-1 towards Hg 2+ and S 2À was demonstrated in living cells, and cell toxicity assay also reveals that the probe P-1 can be used for selective imaging of Hg 2+ and S 2À in living cells.

Research paper thumbnail of Phenothiazine based sensor for naked-eye detection and bioimaging of Hg(II) and F- ions

The design and development of new phenothiazine-based fluorescent probes, which display a selecti... more The design and development of new phenothiazine-based fluorescent probes, which display a selective fluorescence response to mercury and fluoride ions, were described. The probe is the first example that facilitates the detection of Hg 2+ at nanomolar concentrations. The sensitivity of probe P-1 to Hg 2+ and F À was demonstrated in living cells, and cell toxicity assays revealed that probe P-1 can be used for selective imaging of Hg 2+ and F À in living cells. Moreover, the simple probe design presented here may contribute to the development of more efficient and more useful dual-mode probes.