Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
6 results
Search Results
Item Preparation of gold nanoparticles by novel bacterial exopolysaccharide for antibiotic delivery(Elsevier Inc. usjcs@elsevier.com, 2016) Pradeepa, n.; Vidya, S.M.; Mutalik, S.; Bhat, K.U.; Huilgol, P.; Avadhani, K.Aim To develop potent drug delivery agents to treat multidrug resistant (MDR) bacterial infections using gold nanoparticles (AuNPs) prepared by bacterial exopolysaccharide (EPS) being a reducing and stabilizing agent. Methods Gold nanoparticles were prepared by EPS, extracted from Lactobacillus plantarum. AuNPs were characterized by UV-visible spectrophotometer, transmission electron microscope (TEM), zeta potential and Fourier transform infrared spectroscopy. Antibiotics used for functionalization of AuNPs were levofloxacin, cefotaxime, ceftriaxone and ciprofloxacin. The resulted functionalized AuNPs were tested against various MDR bacteria by employing different assays such as well diffusion assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time killing assay. Key findings The nanostructures exhibited excellent bactericidal activity and reduced MIC and MBC against MDR Gram positive and Gram negative bacteria compared to free drugs. Escherichia coli was the most susceptible MDR bacteria followed by Klebsiella pneumoniae and Staphylococcus aureus. TEM results revealed that the bactericidal activity of nanostructures could be mediated by penetration, loss of cytoplasmic contents and cell lysis. Significance Antibiotic functionalized nanostructures were more potent than free drugs and could be used as potent drug delivery vehicles. © 2016 Elsevier Inc. All rights reserved.Item Green Synthesis of Silver and Gold Nanoparticles Using Root Bark Extract of Mammea suriga: Characterization, Process Optimization, and Their Antibacterial Activity(Springer New York LLC barbara.b.bertram@gsk.com, 2016) Poojary, M.M.; Passamonti, P.; Vasudeva Adhikari, A.V.The present study reports the green synthesis of silver and gold nanoparticles (NPs) from their respective precursors AgNO3 and HAuCl4, using root bark extract of Mammea suriga. Further, it describes the influence of various reaction parameters, such as pH, temperature, precursor concentration, and volume of the extract, on the morphology and size of the newly synthesized NPs. The biosynthesized NPs were characterized using UV–Vis spectroscopy, SEM, EDX, XRD, and FTIR. The formation of Ag and Au NPs was confirmed by their UV–Vis spectra. Ag NPs were efficiently synthesized at pH 10, with precursor concentration of 1 mM of AgNO3 and a reaction temperature of 80 °C, while Au NPs were successfully obtained at pH 8, with precursor concentration of either 1 or 3 mM HAuCl4, and the reaction was maintained at room temperature. The SEM study revealed that the particle size decreases with an increase in the extract volume used in the reaction. The XRD analysis confirmed the formation of metallic Ag and Au NPs having an average size of 50 and 22 nm, respectively. Further, the FTIR spectral data established the role of various functional groups of biomolecules involved in bioreduction as well as capping of NPs. The in vitro antibacterial screening results indicated that the NPs are potential antibacterial agents. Conclusively, the overall study showed that the root bark extract of M. suriga is an excellent eco-friendly and non-toxic source for the synthesis of biologically active Ag and Au NPs at optimal conditions. © 2016, Springer Science+Business Media New York.Item Thermal and cost analysis of various air filled double glazed reflective windows for energy efficient buildings(Elsevier Ltd, 2020) Gorantla, G.; Saboor, S.; Vali, S.S.; Mahapatra, D.; Talanki Puttaranga Setty, A.B.; Kim, K.-H.The enormous amount of energy is being consumed by buildings in an attempt to deliver thermal comfort in buildings. This paper aims at reducing/increasing the total solar heat gain through various combinations of double glazed reflective windows of buildings. The spectral characteristics of six reflective glasses namely bronze, green, grey, opal blue, sapphire blue and gold-reflective glasses at a normal angle of incidence by using UV-3600 Shimadzu spectrophotometer according to ASTM E 424 standards were experimentally measured. The solar optical properties of the glasses were deduced by developing a MATLAB code using spectral data which was obtained from experiments in the solar spectrum wavelength range of 300 nm–2500 nm. Thirty air-filled double-glazed reflective windows have been studied for both thermal and cost analysis in the Indian composite climatic zone (New Delhi 28.580 N, 77.200 E). The configuration C13 (Grey reflective glass-Air gap 10 mm-Gold reflective glass) is observed to be the best air-filled double glazed window from the highest annual cost savings ($ 79.29 per annum in SE direction) and lower payback period (1.42 years) point of views among thirty double-glazed reflective glasses studied. The results of this paper are useful in the design of sustainable passive solar buildings. © 2019 Elsevier LtdItem Hybrid Plasmonic Waveguide Based Platform for Refractive Index and Temperature Sensing(Institute of Electrical and Electronics Engineers Inc., 2022) Sahu, S.K.; Reddy, S.K.; Singh, M.; Avrutin, E.A nanoscale 3D hybrid plasmonic waveguide (HPWG) refractive index-cum-temperature sensor has been proposed and simulated in this work. The aqueous analyte (benzene C6H6) sensing is possible over the wavelength range from 1.18∼μ m to 2.2∼μ m. A well-known refractive index (RI) sensing method (or wavelength interrogation) is considered for the proposed Si-TiO2-SiO2-Au nanostructure. The sensor design includes, titanium dioxide (TiO2) layer deposited over the silicon dioxide to enhance the overall sensitivity of the HPWG sensor. The finite element method (FEM) based 3D-numerical simulations are performed for an IR band signal, predicting 1022.75 nm/RIU device sensitivity and 2.95 nm/°C temperature sensitivity. The proposed sensor is suitable for next-generation on-chip biochemical sensing applications with nanoscale dimensions, low cost, and high sensitivity. © 1989-2012 IEEE.Item Growth Reaction of Gold Nanorods in the Presence of Mutated Peptides and Amine-Modified Single-Stranded Nucleic Acids(John Wiley and Sons Ltd, 2023) Sahu, J.K.; Singh, O.; Chakraborty, D.; Sadhu, K.K.Conformation of biomolecules like DNA, peptides and amino acids play vital role during nanoparticle growth. Herein, we have experimentally explored the effect of different noncovalent interaction between a 5′-amine modified DNA sequence (NH2−C6H12-5′-ACATCAGT-3′, PMR) and arginine during the seed-mediated growth reaction of gold nanorods (GNRs). Amino acid-mediated growth reaction of GNRs results in a snowflake-like gold nanoarchitecture. However, in case of Arg, prior incubation of GNRs with PMR selectively produces sea urchin-like gold suprastructures, via strong hydrogen bonding and cation-π interaction between PMR and Arg. This distinctive structure formation strategy has been extended to study the structural modulation caused by two structurally close α-helical RRR (Ac-(AAAAR)3A−NH2) peptide and the lysine mutated KKR (Ac−AAAAKAAAAKAAAARA−NH2) peptide with partial helix at the amino terminus. Simulation studies confirm that a greater number of hydrogen bonding and cation-π interaction between the Arg residues and PMR resulted in the gold sea urchin structure for RRR peptide against KKR peptide. © 2023 Wiley-VCH GmbH.Item Hybrid Plasmonic Circular Aperture Waveguide for Blood Glucose Sensing(Institute of Electrical and Electronics Engineers Inc., 2024) Vankalkunti, S.; Singh, N.; Singh, M.A novel approach for blood glucose (or blood sugar) sensing utilizing a hybrid plasmonic circular aperture waveguide (HPCAW)-based nanostructure is proposed. The reported sensor combines the unique optical properties of plasmonic waveguides and circular aperture to achieve higher sensitivity and specificity in glucose detection. The HPCAW structure is designed to efficiently confine and propagate surface plasmon polaritons (SPPs) along the circular aperture, enabling enhanced light-matter interaction within the sensing region. Through rigorous numerical simulations and validation, we demonstrate the superior performance of the HPCAW sensor in terms of sensitivity (391.72 nm/RIU), figure of merit (FOM) (7.08 RIU-1), and detection accuracy (DA) (0.018 nm-1) compared to conventional glucose sensing techniques. Moreover, the proposed sensor offers inherent advantages, such as label-free detection, compact footprint, and compatibility with microfluidic systems. HPCAW provides a promising platform for the next-generation blood glucose monitoring applications with potential clinical translation. 1558-1748 © 2024 IEEE.