Browsing by Author "Devyani Shukla"

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Carbon Quantum Dot as Electron Transporting Layer in Organic Light Emitting Diode
(Wiley-Blackwell, 2019) Md. Bayazeed Alam; Kanchan Yadav; Devyani Shukla; Ritu Srivastava; Jayeeta Lahiri; Avanish. S. Parmar
Carbon quantum dots derived from banana leaves by a simple hydrothermal process has been used as an electron transport layer to fabricate Organic Light Emitting Diodes. To the best of our knowledge, this is the first report of Carbon QD utilized as an electron transport layer inOLED. Devices with multilayered structureITO/PEDOT: PSS/PFO/CQD/LiF/Al are fabricated on indium tin oxide (ITO) coated glass substrates. Current-Voltage (I−V) curves reveal that the turn-on voltages are reduced from 8 V to 6 V as compared with pristine PFO device.Results show CQD as an ETL has enhanced the performance and efficiency of the OLEDs. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Label-Free Fluorometric Detection of Adulterant Malachite Green Using Carbon Dots Derived from the Medicinal Plant Source Ocimum tenuiflorum
(Wiley-Blackwell, 2019) Devyani Shukla; Fanindra Pati Pandey; Puja Kumari; Nilanjan Basu; Manish K. Tiwari; Jayeeta Lahiri; Ravindra N. Kharwar; Avanish S. Parmar
Food adulteration is an alarming concern in developing countries causing an increased rate of cancer incidents. This study aims to address this concern by detecting adulteration in green vegetables. A facile green one-step and cost-effective strategy to synthesize carbon quantum dots derived from a herbal source has been utilized to design a fluorescence-based sensor for detecting malachite green (MG), a toxic carcinogenic dye, commonly used as an adulterant to give a fresh green look to green vegetables. The leaf-extract of Ocimum tenuiflorum has been used to synthesize highly photostable carbon dots for detecting MG with a limit of detection (LOD) as low as 18 nM. Further, this principle has been utilized to design a prototype calorimetric sensor. The mechanism of the interaction between malachite green and carbon dots has been probed using DFT by employing the SMD solvation model. In addition, CQDs also possess strong antioxidant activity and minimal cytotoxicity enabling their utilization in many biological and sensing applications. This shows the versatility of these easily scalable carbon dots. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Sandalwood-derived carbon quantum dots as bioimaging tools to investigate the toxicological effects of malachite green in model organisms
(Elsevier Ltd, 2020) Devyani Shukla; Megha Das; Dipanshu Kasade; Maneesha Pandey; Ashutosh Kumar Dubey; Sanjeev Kumar Yadav; Avanish Singh Parmar
Malachite green is an N-methylated diaminophenylmethane dye that has generated much concern over its suggestive carcinogenic nature. After its excessive use in aquaculture industry as an effective ectoparasitide, much debate was raised over its toxicological effects leading to scientific studies conducted on animal models. Even after several bans, malachite green is still easily available in many parts of the world and unscrupulously even used to give green vegetables a fresher look. This study aims to address this concern by systematically studying the toxicological effects of malachite green through bioimaging in plant and animal cell and tissue. Sandalwood-derived carbon quantum dots have been used as a bioimaging tool since they are non-cytotoxic and show excellent fluorescence properties. Onion tissues demonstrate the translocation of the dye inside cells having high affinity for the nuclei and cell walls. Toxicological effects on the growth of Vigna radiata (mung beans) have been studied methodically. Bioimaging of the transverse cross-section of the dye-treated plant root shows a significant difference from the control. In animal cells, dose-dependent decrease in cell viability of MG-63 cells was observed with MG. CQD showed good fluorescence in both cytoplasm and nucleus of MG63 cells. In addition, CQDs were employed as a great tool for bioimaging of the histopathologically adverse effects of MG in Golden hamster animal model. This study showed CQDs could be used as an alternative non-site specific fluorescent probe for cell and tissue imaging for better visualization of cell and tissue architectural changes. © 2020 Elsevier Ltd
Understanding the In Situ Mechanistic Control of Plant-Derived Carbon Quantum Dots on the Synthesis of Gold Nanoparticles
(Wiley-Blackwell, 2019) Devyani Shukla; Subhaya Bose; Smarajit P. Choudhury; Vinay K. Sharma; Megha Das; Shivesh Sabbarwal; Sanjeev K. Yadav; Manoj Kumar; Avanish S. Parmar
Arjuna terminalia- derived Carbon Quantum Dots synthesized by hydrothermal method are utilized to investigate the effect of their reaction parameters on the synthesis and growth of gold nanoparticles. In this study, carbon dots are synthesized at two temperatures (160 °C and 200 °C) and two solvents (water and ethanol) to investigate the effect of four variants on the formation of non-cytotoxic gold nanoparticles. They are extensively characterized to understand their different physical and chemical properties. Gold nanoparticles synthesized using ethanol based carbon dots show greater stability. Addition of Type-I collagen stabilizes the gold nanoparticles to form gold nanoparticle-coated collagen fibrils. Further, β-mercaptoethanol initiates a spontaneous precipitation and sedimentation of visible gold micelles similar to “snowing”. This work may help in future to understand the reduction of chloroauric acid using bio-derived plant extracts, microbial consortium and very recently, carbon quantum dots, for specific tailoring of gold nanoparticles for biomedical, surface-enhanced Raman spectroscopy and theranostics applications. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim