Faculty Publications
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Item Study of the properties of SCC with quarry dust(2009) Gowda, M.R.; Narasimhan, M.C.; Karisddappa; Rajeeva, S.V.Granite fines or rock dust is a by-product obtained during crushing of granite rocks and is also called quarry dust (QD). This paper deals with using quarry dust as an alternative to fine aggregate (FA) in SCC and reports the strength behaviour and hardened properties of such SCCs. Although in normal concretes, introducing QD increases the water demand, in SCC, it has been successfully used for increasing the deformability and passing ability of fresh concrete. Also, it was noted that by increasing the pouring heights of an SCC, the compressive strength and splitting tensile strength of concrete were unaffected.Item ZnS semiconductor quantum dots production by an endophytic fungus Aspergillus flavus(Elsevier Ltd, 2016) Uddandarao, P.; Mohan B, R.The development of reliable and eco-friendly processes for the synthesis of metal sulphide quantum dots has been considered as a major challenge in the field of nanotechnology. In the present study, polycrystalline ZnS quantum dots were synthesized from an endophytic fungus Aspergillus flavus. It is noteworthy that apart from being rich sources of bioactive compounds, endophytic fungus also has the ability to mediate the synthesis of nanoparticles. TEM and DLS revealed the formation of spherical particles with an average diameter of about 18 nm and 58.9 nm, respectively. The ZnS quantum dots were further characterized using SEM, EDAX, XRD, UV-visible spectroscopy and FTIR. The obtained results confirmed the synthesis of polycrystalline ZnS quantum dots and these quantum dots are used for studying ROS activity. In addition this paper explains kinetics of metal sorption to study the role of biosorption in synthesis of quantum dots by applying Morris-Weber kinetic model. Since Aspergillus flavus is isolated from a medicinal plant Nothapodytes foetida, quantum dots synthesized from this fungus may have great potential in broad environmental and medical applications. © 2016 Elsevier B.V. All rights reserved.Item Exploring the fungal protein cadre in the biosynthesis of PbSe quantum dots(Elsevier B.V., 2017) Jacob, J.M.; Sharma, S.; Mohan Balakrishnan, R.M.While a large number of microbial sources have recently emerged as potent sources for biosynthesis of chalcogenide quantum dots (QDs), studies regarding their biomimetic strategies that initiate QD biosynthesis are scarce. The present study describes several mechanistic aspects of PbSe QD biosynthesis using marine Aspergillus terreus. Scanning electron microscopic (SEM) studies indicated distinctive morphological features such as abrasion and agglomeration on the fungal biomass after the biosynthesis reaction. Further, the biomass subsequent to the heavy metal/metalloid precursor was characterized with spectral signatures typical to primary and secondary stress factors such as thiol compounds and oxalic acid using Fourier Transform Infra-Red Spectroscopic (FTIR) analysis. An increase in the total protein content in the reaction mixture after biosynthesis was another noteworthy observation. Further, metal-phytochelatins were identified as the prominent metal-ion trafficking components in the reaction mixture using Liquid Chromatography Mass Spectroscopic analysis (LCMS). Subsequent assays confirmed the involvement of metal binding peptides namely metallothioneins and other anti-oxidant enzymes that might have played a prominent role in the microbial metal detoxification system for the biosynthesis of PbSe QDs. Based on these findings a possible mechanism for the biosynthesis of PbSe QDs by marine A. terreus has been elucidated. © 2016 Elsevier B.V.Item Photoluminescence Quenching in Metal Ion (Cu2+, Co2+) Interacted Graphene Quantum Dots(Wiley-VCH Verlag info@wiley-vch.de, 2017) Mishra, P.; Badekai Ramachandra, B.R.Graphene quantum dots (GQD) are nanosized fragments of graphene with finite band gap. Thus, GQDs show excellent photoluminescence (PL) and also possess good electrochemical properties. In the present study, we synthesized GQDs via hydrothermal (HT) method using Graphene oxide as prepared from improved Hummer's method as a precursor with several modifications. The effect of the variation in the photoluminescence and electrochemical properties of the as-prepared GQDs were studied. Average particle size of the as-synthesized GQDs was roughly 30 nm and produced blue PL on excitation with a wavelength of 365 nm. On reacting the GQDs with Cupric Nitrate and Cobalt Nitrate in separate batches, a significant decrease in the intensity of PL was observed. This quenching of PL of GQDs has been utilized in the qualitative estimation of Metal ion (Cu2+ and Co2+) species in aqueous media. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimItem Synthesis and characterization of graphene quantum dots and their size reduction using swift heavy ion beam(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2018) Mishra, P.; Badekai Ramachandra, B.R.Graphene quantum dots (GQDs) are nanosized fragments of graphene displaying quantum confinement effect. They have shown to be prepared from various methods which include ion beam etching of graphene. However, recently the modification of the GQDs has garnered tremendous attention owing to its suitability for various applications. Here, we have studied the effect of swift ion beam irradiation on the properties of GQDs. The ion beam treatment on the GQDs exhibited the change in observed photoluminescence of GQDs as they exhibited a blue luminescence on excitation with longwave UV (?365 nm) due to the reduction in size and removal of the ethoxy (–C–O–C–) groups present on the quantum dots. This was confirmed by transmission electron microscopy, particle size analysis, and Fourier transform infrared spectroscopy. © 2018 Informa UK Limited, trading as Taylor & Francis Group.Item Role of graphene quantum dots synthesized through pyrolysis in the release behavior of temperature responsive poly (N,N-diethyl acrylamide) hydrogel loaded with doxorubicin(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2018) Havanur, S.; JagadeeshBabu, P.E.We have reported the synthesis and characterization of new drug carrier using Poly (N,N-diethyl acrylamide) (PDEA) and graphene quantum dots (GQDs). PDEA is a stimuli-responsive, macroporous polymer which has the ability to respond to change in surrounding temperature and addition of GQDs will help in improving the inherent characteristics of PDEA. In this research work, PDEA hydrogels along with GQDs have been synthesized by free radical polymerization. The effect of various concentrations of GQDs on the property of PDEA hydrogel was studied. The structural analysis of synthesized hydrogels was done using Fourier transform infrared spectroscopy (FT–IR). The internal surface morphology of porous hydrogels was observed using scanning electron microscope (SEM) micrographs. From the analysis, it has been observed that the equilibrium swelling ratio (ESR) and reswelling kinetics of the hydrogel significantly increased as the GQDs content was varied. The cancer drug (an anthracycline that is used for cancer chemotherapy) Doxorubicin (DOX) release behavior was studied and found that the performance of hydrogel is dependent on hydrogel composition, time, and surrounding temperature. The cytotoxicity of GQDs incorporated PDEA hydrogels gave a significant report which supports the potential application of hydrogel as an intelligent drug carrier. © 2018, © 2018 Taylor & Francis Group, LLC.Item Surface plasmon resonance sensor using polypyrrole-chitosan/graphene quantum dots layer for detection of sugar(Institute of Physics Publishing helen.craven@iop.org, 2019) Sadrolhosseini, A.R.; Abdul Rashid, S.; Jamaludin, N.; Bin Muhammad Noor, A.S.M.; Isloor, A.M.The Polypyrrole-chitosan/graphene quantum dots nanocomposite layer was prepared by using electrochemical deposition on the surface of gold-coated glass. The prepared layer was used to detect and measure the low concentration of glucose, fructose, and sucrose, using the surface plasmon resonance sensor. X-ray diffraction spectroscopy, and field emission scanning electron microscopy confirmed the GQDs as being formed in the composite layer. The thickness of the polypyrrole-chitosan/graphene quantum dots composite layer was in the range of 10.2 nm to 46.5 nm. The sensitivity of the sensor for glucose detection was higher than fructose and sucrose. The sensor limit and the response time were about 1 ppm and 320 s, respectively. © 2019 IOP Publishing Ltd.Item Experimental and molecular modeling of interaction of carbon quantum dots with glucose(Springer Verlag service@springer.de, 2019) Sadrolhosseini, A.R.; Abdul Rashid, S.A.; Jamaludin, N.; Isloor, A.M.Carbon Quantum Dots are a 0D dimension nanomaterial and they have promising properties, such as fluorescence. In this study, the carbon quantum dots were derived from biochar. The prepared sample was characterized using a UV–visible spectrometer, Fourier transform infrared spectroscopy, and fluorescence spectroscopy, and the morphology was investigated using a high-resolution transmission electron microscopy image. The linear and nonlinear refractive indies were obtained from a UV–visible spectrum and a Z-scan signal. The carbon quantum dots were combined with glucose, and then the variation between the fluorescence spectrum and response time were investigated. The interaction of the carbon quantum dots with the glucose was simulated using density functional theory for finding the stable molecular in the lower energy. Consequently, the carbon quantum dots interacted with the glucose in van der Waals bonding. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.Item Poly(N,N-diethyl acrylamide)/functionalized graphene quantum dots hydrogels loaded with doxorubicin as a nano-drug carrier for metastatic lung cancer in mice(Elsevier Ltd, 2019) Havanur, S.; Batish, I.; Cheruku, S.P.; Gourishetti, K.; JagadeeshBabu, J.; Kumar, N.Cancer has emanated as a daunting menace to human-kind even though medicine, science, and technology has reached its zenith. Subsequent scarcity in the revelation of new drugs, the exigency of salvaging formerly discovered toxic drugs such as doxorubicin has emerged. The invention of drug carrier has made drug delivery imminent which is ascribable to its characteristic traits of specific targeting, effective response to stimuli and biocompatibility. In this paper, the nanoscale polymeric drug carrier poly(N,N-diethyl acrylamide) nanohydrogel has been synthesized by inverse emulsion polymerization. Lower critical solution temperature of the polymeric carrier has been modified using graphene quantum. The particle size of pure nanohydrogel was in the range of 47 to 59.5 nm, and graphene quantum dots incorporated nanohydrogels was in the range of 68.1 to 87.5 nm. Doxorubicin (hydroxyl derivative of anthracycline) release behavior as a function of time and temperature was analyzed, and the Lower critical solution temperature of the synthesized nanohydrogels has been found to be in the range of 28–42 °C. Doxorubicin release characteristics have improved significantly as the surrounding temperature of the release media was increased near to physiological temperature. Further, the cumulative release profile was fitted in the different kinetic model and found to follow a Fickian diffusion release mechanism. The hydrogel was assessed for its cytotoxicity in B16F10 cells by MTT assay. In-vivo studies were done to study the lung metastasis by melanoma cancer and the results showed a rational favorable prognosis which was confirmed by evaluating hematological parameters and the non-immunogenic nature of nanohydrogel by cytokine assay. Comprehensively, the results suggested that poly(N,N-diethyl acrylamide) nanohydrogels have potential application as an intelligent drug carrier for melanoma cancer. © 2019 Elsevier B.V.Item Aggregative ways of graphene quantum dots with nitrogen-rich edges for direct emission spectrophotometric estimation of glucose(Elsevier B.V., 2019) Mishra, P.; Badekai Ramachandra, B.R.We report a facile one step in-situ synthesis of amino-functionalized graphene dots. These quantum dots were employed for the detection of glucose in both standard aqueous solutions and commercially available fruit juice to assess its practicability. The characterization of the quantum dots revealed that they were decorated with amine functionality. Additionally, the interaction between glucose and amine functionalized graphene quantum dots gave enhancement in the UV–vis absorption and photoluminescence (PL) due to aggregation of quantum dots via glucose link. Therefore, the quantum dots were able to detect the concentration of glucose in solution exhibiting linearity from 0.1 to 10 mM and 50–500 mM with a sensitivity transition from 10 mM to 50 mM. The limit of detection for the determination of glucose was found to be 10 ?M. This determination was agreed from both UV–Vis absorption and PL spectroscopy. However, the PL emission method of determination was most suited with its very high accuracy of 98.04 ± 1.96% and 97.33 ± 2.67% for the linear range of glucose concentration within 0.1–10 mM and 50–500 mM, respectively. The PL enhancement was highly selective towards glucose in mixture of other form of sugars making it suitable for determining glucose in food samples. © 2019