Browsing by Author "Kadam, V.V."

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    Biological synthesis of metal selenide nanoparticles and their applications
    (IWA Publishing, 2021) Mohan Balakrishnan, R.M.; Kadam, V.V.
    [No abstract available]
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    Fluorometric detection of bisphenol A using ?-cyclodextrin-functionalized ZnO QDs
    (2020) Kadam, V.V.; Raj Mohan, Balakrishnan; Ettiyappan, J.P.
    The estrogenic property of bisphenol A (BPA) leads to potential adverse health and ecological effects. A simple, selective, and cost-effective sensor capable of detecting BPA would have a noteworthy relevance for the environmental system. The present work illustrates the synthesis and characterization of ?-cyclodextrin (?-CD) functionalized zinc oxide (ZnO) quantum dots (QDs) for the selective detection of BPA. BPA has a fluorescence quenching effect on functionalized ZnO QDs, and the decrease in fluorescence intensity is associated with the BPA concentration between 2 and 10 ?M. Under the optimum reaction condition, a good linear correlation was obtained between relative fluorescence-quenching intensity of ?-cyclodextrin-functionalized ZnO QDs and BPA concentration (R2 = 0.9891). The lower detection limit of functionalized QDs for BPA was estimated to be 0.19 ?M, which is lower than the toxic limits in aquatic biota. The fluorescence-based detection of BPA may be ascribed to the electron transfer mechanism, which is elucidated with scientific details from the literature. 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
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    Fluorometric detection of bisphenol A using ?-cyclodextrin-functionalized ZnO QDs
    (Springer Science and Business Media Deutschland GmbH, 2021) Kadam, V.V.; Mohan Balakrishnan, R.M.; JagadeeshBabu, J.
    The estrogenic property of bisphenol A (BPA) leads to potential adverse health and ecological effects. A simple, selective, and cost-effective sensor capable of detecting BPA would have a noteworthy relevance for the environmental system. The present work illustrates the synthesis and characterization of ?-cyclodextrin (?-CD) functionalized zinc oxide (ZnO) quantum dots (QDs) for the selective detection of BPA. BPA has a fluorescence quenching effect on functionalized ZnO QDs, and the decrease in fluorescence intensity is associated with the BPA concentration between 2 and 10 ?M. Under the optimum reaction condition, a good linear correlation was obtained between relative fluorescence-quenching intensity of ?-cyclodextrin-functionalized ZnO QDs and BPA concentration (R2 = 0.9891). The lower detection limit of functionalized QDs for BPA was estimated to be 0.19 ?M, which is lower than the toxic limits in aquatic biota. The fluorescence-based detection of BPA may be ascribed to the electron transfer mechanism, which is elucidated with scientific details from the literature. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
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    Mechanistic insight into the endophytic fungus mediated synthesis of protein capped ZnO nanoparticles
    (2019) Kadam, V.V.; Ettiyappan, J.P.; Raj Mohan, Balakrishnan
    Present investigation is focused on the development of environment friendly protocol for ZnO nanoparticles synthesis using mycelial free filtrate of unexplored endophytic fungus Cochliobolus geniculatus. Zinc metal tolerant endophyte was isolated from leaves of Nothapodytes foetida and identified based on rDNA internal transcribed spacer region sequence. Surface plasmon resonance examined by UV VIS spectroscopy analysis confirmed the synthesis of ZnO nanoparticles; exhibiting a band gap of 3.28 eV. The obtained nanoparticles were characterized by energy dispersive X-ray (EDX), high resolution transmission electron microscopy and XRD analysis. The synthesized ZnO nanoparticles were found to be polydispersed and well distributed deprived of agglomeration, crystalline, quasi spherical particles exhibiting a narrow range distribution. Fluorescence, FTIR and UV VIS spectra depicted presence of extracellular proteins which was further confirmed by SDS-PAGE study that displayed occurrence of 52 kDa and 58 kDa protein bands involved in the synthesis of ZnO nanoparticles and further act as capping material. 2019 Elsevier B.V.
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    Mechanistic insight into the endophytic fungus mediated synthesis of protein capped ZnO nanoparticles
    (Elsevier Ltd, 2019) Kadam, V.V.; JagadeeshBabu, P.E.; Mohan Balakrishnan, R.
    Present investigation is focused on the development of environment friendly protocol for ZnO nanoparticles synthesis using mycelial free filtrate of unexplored endophytic fungus Cochliobolus geniculatus. Zinc metal tolerant endophyte was isolated from leaves of Nothapodytes foetida and identified based on rDNA internal transcribed spacer region sequence. Surface plasmon resonance examined by UV–VIS spectroscopy analysis confirmed the synthesis of ZnO nanoparticles; exhibiting a band gap of 3.28 eV. The obtained nanoparticles were characterized by energy dispersive X-ray (EDX), high resolution transmission electron microscopy and XRD analysis. The synthesized ZnO nanoparticles were found to be polydispersed and well distributed deprived of agglomeration, crystalline, quasi spherical particles exhibiting a narrow range distribution. Fluorescence, FTIR and UV–VIS spectra depicted presence of extracellular proteins which was further confirmed by SDS-PAGE study that displayed occurrence of 52 kDa and 58 kDa protein bands involved in the synthesis of ZnO nanoparticles and further act as capping material. © 2019 Elsevier B.V.
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    Photocatalytic Degradation of Caffeine Using Biogenic Silver Doped Zinc Oxide Nanoparticles
    (Springer Science and Business Media Deutschland GmbH, 2025) Gudadur, K.S.; Mohan Balakrishnan, R.; Kadam, V.V.
    This study explores the degradation of caffeine using biogenic silver-doped zinc oxide (Ag/ZnO) nanoparticles (NPs) as a heterogeneous photocatalyst. Zinc nitrate (Zn(NO3)2) and silver nitrate (AgNO3) were utilized as precursors in the biogenic synthesis of Ag/ZnO NPs. The synthesis involved incubating the mixtures for 72 h at pH 11 and a temperature of 28 °C ± 1 °C. The incorporation of silver resulted in a reduction of the bandgap energy of ZnO from 3.33 to 2.29 eV, confirming the successful synthesis of Ag/ZnO NPs. Key parameters were optimized to enhance caffeine degradation efficiency, including catalyst loading (5, 10, 15, and 20 mg), initial pollutant concentration (20, 40, 60, 80, 100, 120, and 140 ppm), hydrogen peroxide (H2O2) concentration (1, 3, 5, and 7 mM), and radiation exposure duration (20 to 200 min). The optimal conditions achieved a maximum degradation efficiency of 85.78% with a pollutant concentration of 60 ppm, catalyst loading of 15 mg/100 mL at pH 8, 5 mM H2O2 as an electron acceptor, and a radiation exposure duration of 160 min. The kinetics of caffeine degradation were found to follow a pseudo-first-order reaction. After 160 min of irradiation, the removal rates of chemical oxygen demand (COD) and total organic carbon (TOC) were 71.23% and 67.87%, respectively, indicating significant mineralization of caffeine. Additionally, the photocatalyst demonstrates impressive reusability and stability, maintaining 81.3% of its degradation capacity for caffeine even after five cycles. This highlights the excellent reusability of Ag/ZnO, making it a sustainable and environmentally friendly choice for treating industrial wastewater. Notably, the method is environmentally friendly and does not involve toxic chemicals.; To synthesize Ag@ZnO NPs using an endophytic fungal isolate from medicinal plant. Nothapodytes foetida. To study the morphological, structural, optical, and stability properties of biogenic Ag@ZnO NPs. To investigate the caffeine degradation and its underlying kinetic analysis. To characterize caffeine degradation using total organic carbon (TOC) and chemical oxygen demand (COD) analysis. © University of Tehran 2025.; © University of Tehran 2025.
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    Photocatalytic degradation of p-nitrophenol using biologically synthesized ZnO nanoparticles
    (Springer Science and Business Media Deutschland GmbH, 2021) Kadam, V.V.; Shanmugam, S.D.; JagadeeshBabu, J.; Mohan Balakrishnan, R.M.
    The present work deals with the photocatalytic degradation of p-nitrophenol as it is a United States Environmental Protection Agency-listed priority pollutant and has adverse environmental and health effects. To eradicate the detrimental environmental impact of p-nitrophenol, the biologically synthesized ZnO nanoparticles were used as a photocatalyst. The degradation of p-nitrophenol was confirmed by decreasing the absorbance value at a characteristic wavelength of 317 nm using the UV-vis spectrophotometer. Reaction parameters such as ZnO photocatalyst concentration of 0.1 g/L at pH 11 in the presence of H2O2 (5 mM) were found to be optimum conditions for p-nitrophenol degradation. The photocatalytic degradation was slowly enhanced in the presence of H2O2 as an electron acceptor. The kinetics of nitrophenol degradation was studied, which follows the pseudo-first-order reaction. The photocatalytic degradation of p-nitrophenol was characterized by using total organic carbon, chemical oxygen demand, and high-performance liquid chromatography analyses. This method is found to be effective as it is environmentally friendly, free of toxic chemicals. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.