Browsing by Author "Balu, Krishnakumar"

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ANTIOXIDANT (IN VITRO), ANTIDIABETIC (IN VITRO) AND PHOTOCATALYTIC ACTIVITY OF COSTUS SPECIOSUS LEAF EXTRACT ASSISTED CS-AG-TIO2 COMPOSITES
(Springer Link, 2019-10-24) Chinnasamy, Surya; Nayagam, Agnel Arul John; Venkatesan, Pandiyan; Parasuraman, Amutha; Abílio José, Fraga do Nascimento Sobral; Balu, Krishnakumar
The researchers have currently targeted bio-synthesis nanoparticles (NPs) and their potential applications toward bio and photocatalytic field. The in vitro antidiabetic activity of noble metal modified TiO2 is really scare in literature. In the present work, green synthesis of CS-Ag nanoparticles was achieved through Costus speciosus (Crape ginger, an Indian ornamental plant, has long been medicinally used in traditional systems of medicine) leaf extract, and followed by solvothermal synthesis of CS-Ag-TiO2 composites. The prepared nanocomposites effectively utilized for in vitro antioxidant, in vitro antidiabetic study and azo dye AB 1 degradation under visible light.
BICL3-MODIFIED PERLITE AS AN EFFECTIVE CATALYST FOR SELECTIVE ORGANIC TRANSFORMATIONS: A GREEN PROTOCOL
(Springer Link, 2019-05-02) Kannan, Brindha; Parasuraman, Amutha; Balu, Krishnakumar; Abílio José, Fraga do Nascimento Sobral
A new perlite supported Bismuth Chloride (BiCl3) was used as an efficient heterogeneous catalyst for the synthesis of heterocyclic compounds viz., quinoxalines and dihydropyrimidinones. Fourier-transform infrared spectroscopy (FT–IR), scanning electron microscopy, energy dispersive spectra, X-ray diffractometry, thermogravimetric analysis and Brunauer–Emmett–Teller surface area analytical techniques were employed to characterize the prepared catalyst. Initially, the catalytic activity of the prepared BiCl3-Perlite was tested towards synthesis of simple quinoxaline derivatives at room temperature. The effect of solvent in the preparation of quinoxaline was also examined. The formed products were confirmed by their physical (melting point) and spectral data (FT–IR, 1H and 13C-NMR). In order to implement the activity of the BiCl3-Perlite catalyst, a multicomponent reaction was adopted for synthesis of dihydropyrimidinones under solvent free conditions in a micro oven. The use of recyclable heterogeneous solid acid catalyst makes the reaction simple with minimum chemical waste, shorter reaction time, easy workup and products in good yield.
COSTUS SPECIOSUS LEAF EXTRACT ASSISTED CS-PT-TIO2 COMPOSITES: SYNTHESIS, CHARACTERIZATION AND THEIR BIO AND PHOTOCATALYTIC APPLICATIONS
(Elsevier, 2019-11-05) Surya, C; Agnel Arul John, N; Pandiyan, V; Ravikumar, S; Amutha, P; Abilio J.F.N, Sobral; Balu, Krishnakumar
The antioxidative and antidiabetic properties of Costus speciosus leaf extract assisted nanoparticles (CS–Pt modified TiO2) were compared with pristine TiO2 NPs along with standard ascorbic acid (AA). CS-Pt nanoparticles were synthesized through bioreduction process and supported on titanium dioxide semiconductor. Costus speciosus (CS) leaf extract was used as reducing and capping agent. Initially, CS-Pt nanoparticles synthesis was carried out with ethanolic extract of CS, later, two different wt% of CS-Pt supported TiO2 were prepared through sol-gel cum solvothermal process. The prepared materials have been characterized using different characterization techniques such as XRD, FT-IR, Raman, SEM, HR-TEM, EDS, DRS, PL and XPS measurements. CS-Pt-TiO2 nanocomposites showed well dispersion of Pt nanoparticles on TiO2 surface. The prepared materials have been effectively utilized for in-vitro antioxidant and in vitro antidiabetic activity. Moreover, the photocatlytic activity of the materials has been tested toward NBB degradation under visible light. CS-Pt NPs modified TiO2 composites show better activity when compared with pristine TiO2 in all cases.
FACILE APPROACH FOR GREEN SYNTHESIS OF FLUORESCENT CARBON DOTS FROM MANIHOT ESCULENTA AND THEIR POTENTIAL APPLICATIONS AS SENSOR AND BIO-IMAGING AGENTS
(Elsevier, 2022-03) Monisha, Sivanandhan; Amutha, Parasuraman; Chinnasamy, Surya; Komalavalli, Lakshminarayanan; Balu, Krishnakumar; Durai, Mani; Young-Ho, Ahn
An eco-friendly approach for the synthesis of blue fluorescent carbon dots (CDs) using Manihot esculenta with an average size of 3–5 nm through hydrothermal method has been reported. Functionality of the prepared CDs was characterized by FT-IR spectroscopy. Structural and morphological characterisation were carried with XRD and TEM techniques, these studies exposed amorphous nature of carbons dots with spherical shape. Optical properties of CDs were examined using UV–Visible and Photoluminescence spectral techniques. Owing to strong blue fluorescence, CDs were evaluated for its ability to sense various heavy metal ions. Attributable to significant response towards Fe3+ ions among different metal ions tested (Al3+, Cu+, Co2+, Pb2+, Zn2+, Fe3+, Ca2+, Hg2+ and Mg2+), CDs were used as a selective fluorescence probe for detection of Fe3+. The bioimaging and cytotoxicity aspects of CDs on MDA MB-231 breast cancer cell lines were confirmed by localised experiments. The synthesised CDs were found to be non-toxic even at their high concentration of 500 µg/mL.
FACILE APPROACH FOR GREEN SYNTHESIS OF FLUORESCENT CARBON DOTS FROM MANIHOT ESCULENTA AND THEIR POTENTIAL APPLICATIONS AS SENSOR AND BIO-IMAGING AGENTS
(Elsevier, 2022-03) Monisha, Sivanandhan; Amutha, Parasuraman; Chinnasamy, Surya; Komalavalli, Lakshminarayanan; Balu, Krishnakumar; Durai, Mani; Young-Ho, Ahn
An eco-friendly approach for the synthesis of blue fluorescent carbon dots (CDs) using Manihot esculenta with an average size of 3–5 nm through hydrothermal method has been reported. Functionality of the prepared CDs was characterized by FT-IR spectroscopy. Structural and morphological characterisation were carried with XRD and TEM techniques, these studies exposed amorphous nature of carbons dots with spherical shape. Optical properties of CDs were examined using UV–Visible and Photoluminescence spectral techniques. Owing to strong blue fluorescence, CDs were evaluated for its ability to sense various heavy metal ions. Attributable to significant response towards Fe3+ ions among different metal ions tested (Al3+, Cu+, Co2+, Pb2+, Zn2+, Fe3+, Ca2+, Hg2+ and Mg2+), CDs were used as a selective fluorescence probe for detection of Fe3+. The bioimaging and cytotoxicity aspects of CDs on MDA MB-231 breast cancer cell lines were confirmed by localised experiments. The synthesised CDs were found to be non-toxic even at their high concentration of 500 µg/mL.
PERLITE IMPREGNATED WITH HPA/Α-FE2O3: MAGNETICALLY SEPARABLE CATALYST FOR THE SYNTHESIS OF 3,3,6,6-TETRAMETHYL-9-SUBSTITUTED-3,4,6,7-TETRAHYDRO-2H-XANTHENE-1,8-(5H,9H)-DIONES
(Elsevier, 2021-10) Komalavalli, Lakshminarayanan; Amutha, Parasuraman; Manawwer, Alam; Naushad, Ahmad; Balu, Krishnakumar; Annamalai, Raja; Misook, Kang
Phosphotungstic acid (HPA)/α-Fe2O3-loaded Perlite has been prepared as a recyclable heterogeneous catalyst for the synthesis of xanthenes. The prepared catalyst has been characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM) with selected-area electron diffraction (SAED) pattern analysis, thermogravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET) measurements. XRD peaks at 2θ = 9.08° and 26.73° (HPA) and 36.03°, 39.72°, and 62.6° (α-Fe2O3) showed efficient loading of HPA/α-Fe2O3 on the Perlite surface. TEM images of the prepared HPA/α-Fe2O3/Perlite corroborated the successful loading of α-Fe2O3 on the Perlite. Advantages of this new protocol include facile handling, low cost, easy work-up procedure, and remarkable reusability over several cycles without loss of the catalytic activity.
SYNTHESIS, CHARACTERIZATION OF GELATIN ASSISTED ZNO AND ITS EFFECTIVE UTILIZATION OF TOXIC AZO DYE DEGRADATION UNDER DIRECT SUNLIGHT
(Elsevier, 2021-03) Balu, Krishnakumar; Ali, Alsalme; Fahad A, Alharthi; Durai, Mani; Anandan, K; Parasuraman, Amutha; Abilio J FN, Sobral
A highly solar active gelatin assisted ZnO (g/ZnO) was successfully synthesized by a sol-gel method. The photocatalyst was characterized by FE-SEM, HR-TEM, XRD, DRS, PL, FT-IR and Raman spectra. The prepared ZnO and g/ZnO were effectively utilized for toxic AB 1 azo dye degradation under direct sunlight. About 100% of degradation occurred with g/ZnO in a shorter time compared with prepared ZnO. The higher efficiency of g/ZnO in azo dye degradation under solar light may be due to higher visible light absorbance of g/ZnO compared with the prepared ZnO. A suitable degradation mechanism was proposed for AB 1 degradation under sunlight by g/ZnO. The g/ZnO was found to be sable and reusable. The addition of scavengers contributes a significant decrease in the photodegradation efficiency of the catalyst.