Faculty Publications
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Item A perspective of advanced biosensors for environmental monitoring(Elsevier, 2019) Mohan Balakrishnan, R.M.; Uddandarao, U.; Raval, K.; Raval, R.Biosensor technology has developed in leaps and bounds due to multidisciplinary approach between biotechnology and nanotechnology. This synergy provided much needed characteristic features, such as sensitivity and selectivity to the biosensor technology. Biosensors are venerated as superior entities for electrochemical, optical, and calorimetric-based sensing because of their exceptional size properties. They are the potential tools, which exhibited the feasibility and potential in detecting various biological, physical, chemical, radiological contaminants in water. This book chapter outlines the overview of various types of sensors, especially on chalcogen-based semiconductor nanoparticles. In this scenario, green route nanoparticles which employ PbSe quantum dots synthesis via marine Aspergillus terreus and ZnS/PbS nanoparticles via an endophytic fungus Aspergillus flavus are focused in this chapter. The book chapter also discusses about highly selective biogenic nanosensors which play a significant role in improving the capacity of biosensors due to their size tuneable quantum confinement effects. Potential applications of these biosensors for environmental monitoring are discussed. © 2019 Elsevier Inc. All rights reserved.Item Insights on the advanced processes for treatment of inorganic water pollutants(Elsevier, 2020) Mohan Balakrishnan, R.M.; Uddandarao, P.; Manirethan, V.; Raval, K.A remarkable increase in the discharge of inorganic pollutants globally from various sources such as mines, industries, or agricultural lands is a major threat to the environment. Development of novel methodologies to mitigate the effects caused by inorganic pollutants in water is crucial in addressing environmental issues. In this regard, various biological sources as nanosorbents and biosensors are venerated as superior entities for the detection and removal of inorganic contaminants. This chapter summarizes the utility of marine bacterial melanin- and fungal-based selenium nanoparticles for the adsorption and further reports endophytic fungal–based ZnS and PbS nanoparticles for the detection of inorganic pollutants from the aqueous systems; moreover, it gives a perspective on current challenges for the removal of contaminants. © 2020 Elsevier Inc. All rights reserved.Item Decolorization of Reactive Blue 220 aqueous solution using fungal synthesized Co3O4 nanoparticles(IWA Publishing, 2020) Valappil, R.S.K.; Vijayanandan, A.S.; Mohan Balakrishnan, R.M.In this work, the photocatalytic activity of the biosynthesized cobalt oxide (Co3O4) nanoparticle (NP) is investigated using a textile dye Reactive Blue 220 (RB220) and decolorization % was monitored using UV–Vis spectrophotometer. The photocatalytic activity has been observed maximum at alkaline pH of 9, NP dosage of 250 mg/L, and reaction time of 270 min. In the presence of UV light irradiation, a maximum dye concentration of 10 mg/L was treated effectively using 150 mg/L NP, and 67% decolorization was achieved. Reaction kinetics has been analyzed, and the reaction followed the pseudo kinetics model with an activation energy of 484 kJ mol1. © 2020 IWA Publishing.Item Photocatalytic degradation of Irgalite violet dye using nickel ferrite nanoparticles(IWA Publishing, 2020) Vijay, S.; Mohan Balakrishnan, R.M.; Rene, E.R.; Priyanka, U.Nanotechnologies have prominent applications in the field of science and technology owing to their size-tunable properties providing a promising approach for degradation of various pollutants. In this scenario, the present work aims to study the effect of nickel ferrite nanoparticles on the degradation of Irgalite violet dye by Fenton’s reaction using oxalic acid as an oxidizing agent in the presence of sunlight. The effect of pH and adsorbent dosage on the rate of dye degradation was monitored. Based on these studies it was observed that 99% dye degradation was achieved for catalyst dosage of 0.2 g, 400 ppm dye concentration and 2.0 mM oxalic acid at pH 3.0 within 60 min. The studies reveal that the degradation follows pseudo-first-order kinetics and the catalyst reusability remained constant almost for five cycles. Further, nickel ferrite nanoparticles are proven to be an efficient alternative for the removal of dyes from coloured solutions. © 2020 IWA Publishing.Item Biological synthesis of metal selenide nanoparticles and their applications(IWA Publishing, 2021) Mohan Balakrishnan, R.M.; Kadam, V.V.[No abstract available]Item The uptake mechanism of Cd(II), Cr(VI), Cu(II), Pb(II), and Zn(II) by mycelia and fruiting bodies of Galerina vittiformis(Hindawi Publishing Corporation 410 Park Avenue, 15th Floor, 287 pmb New York NY 10022, 2013) Damodaran, D.; Mohan Balakrishnan, R.M.; Shetty K, K.Optimum concentrations of heavy metals like copper, cadmium, lead, chromium, and zinc in soil are essential in carrying out various cellular activities in minimum concentrations and hence help in sustaining all life forms, although higher concentration of these metals is lethal to most of the life forms. Galerina vittiformis, a macrofungus, was found to accumulate these heavy metals into its fleshy fruiting body in the order Pb(II) > Cd(II) > Cu(II) > Zn(II) > Cr(VI) from 50 mg/kg soil. It possesses various ranges of potential cellular mechanisms that may be involved in detoxification of heavy metals and thus increases its tolerance to heavy metal stress, mainly by producing organic acids and phytochelatins (PCs). These components help in repairing stress damaged proteins and compartmentalisation of metals to vacuoles. The stress tolerance mechanism can be deduced by various analytical tools like SEM-EDX, FTIR, and LC-MS. Production of two kinds of phytochelatins was observed in the organism in response to metal stress. © 2013 Dilna Damodaran et al.Item Biosynthesis of lead selenide quantum rods in marine Aspergillus terreus(2014) Mary Jacob, J.; Mohan Balakrishnan, R.M.; Kumar, U.B.Biosynthesis of fluorescent, semiconductor lead selenide (PbSe) quantum rods was initiated in lead and selenium tolerant marine Aspergillus terreus. TEM and SEM images revealed the formation of rod like structures having an average diameter of 59 nm. Compositional analysis using EDAX followed by optical and structural characterization by XRD, UV-vis and FTIR spectrophotometry confirmed the biogenesis of crystalline PbSe nanoparticles with quantum confinement effects. © 2014 Elsevier B.V.Item Biosynthesis and optimization of silver nanoparticles by endophytic fungus Fusarium solani(Elsevier, 2014) Sogra Fathima, B.; Mohan Balakrishnan, R.M.A mathematical model for optimization of factors influencing the biosynthesis of silver nanoparticles by an endophytic fungus Fusarium solani was designed. A high determination coefficient R2 of 99.3% was obtained. Structural characterization by UV-vis, TEM, XRD and FTIR revealed the formation of spherical nanoparticles. © 2014 Elsevier B.V.Item Optimization and kinetic modeling of cell-associated camptothecin production from an endophytic fusarium oxysporum NFX06(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2015) Musavi, S.F.; Dhavale, A.; Mohan Balakrishnan, R.M.The production of cell-associated camptothecin (CPT) from an endophytic fungus Fusarium oxysporum NFX06 isolated from Nothapodytes foetida and its kinetics studies were proposed. Response surface methodology (RSM) based on central composite design (CCD) was used to construct a model to describe the effects of substrate concentration. Three independent variables (dextrose, peptone, and MgSO4) were successfully employed to study the yield of CPT under submerged fermentation. The maximum yield of CPT obtained from CCD was about 598.0 ng/g biomass. The model-validated optimum predicted CPT yield and experimental CPT yield from the biomass were found to be 628.08 ng/g and 610.09 ng/g at the concentrations of dextrose 42.64 (g/L), peptone 9.23 (g/L), and MgSO4 0.26 (g/L) respectively. The predicted yield of CPT was 4.90% higher than the value obtained from CCD and 2.85% higher than the value obtained from experiment conducted at optimum conditions. The kinetic parameters, maximum specific growth rate ?max = 1.212 day-1, growth-associated CPT production coefficient (? = 29.35 ng/g biomass), and non-growth-associated CPT production coefficient (? = 0.03 ng CPT/g biomass-day) were obtained. The logistic model was found suitable to predict mycelial growth with a high determination coefficient (R2). Luedeking-Piret and modified Luedeking-Piret models were employed to represent the product kinetics and substrate consumption kinetics. A good concurrence was found between the experimental and predicted values, representing that the unstructured models were able to illustrate the fermentation profile effectively. © 2015 Copyright Taylor & Francis Group, LLC.Item Optimised microwave-assisted biosynthesis of silver nanoparticles from Nothapodytes foetida leaf extracts and its anti-microbial activities(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2016) Roopesh, R.; Geedhika, G.; D'Souza, J.; Anandhan, S.; Bhat, K.U.; Jaya M, J.; Fathima B, S.; Mohan Balakrishnan, R.M.The present investigation reports the biogenesis of silver nanoparticles (Ag NPs) using extracts of a medicinal plant Nothapodytes foetida. Total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) assay were carried out for the microwave-assisted extract (MAE) of N. foetida using methanol as solvent and the conditions for extraction were optimised by response surface methodology (RSM). The effects of operating variables such as extraction time, temperature and ratio of sample to solvent were studied using central composite design (CCD). A mathematical model with a high determination coefficient (R2) for TPC (0.991) and FRAP (0.995) was obtained. The optimal conditions of extraction for TPC were 48.6 ºC, 23.15 min and 2.04:30 (g/mL) and for FRAP 52.31ºC, 12.32 min and 1.67: 30 (g/mL). Under these conditions, the experimental yields of TPC and FRAP were 2.426 mg gallic acid equivalents (GAE)/g dry powder and 14.985mg of FeSO4·7H2O/g of dry powder, respectively. Ag NPs were characterised using UV–Vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The synthesised Ag NPs have also shown potent activity against the human pathogenic Staphylococcus aureus. © 2016 Informa UK Limited, trading as Taylor & Francis Group.