School Of Basic And Applied Sciences

Permanent URI for this communityhttps://kr.cup.edu.in/handle/32116/17

Browse

Has files: NoSubject: search.filters.subject.DNA

Search Results

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    Peptide Nucleic Acids: Recent Developments in the Synthesis and Backbone Modifications
    (Academic Press Inc., 2023-09-18T00:00:00) Singh, Gurpreet; Monga, Vikramdeep
    Nucleic acid represents the ideal drug candidate for protein targets that are hard to target or against which drug development is not easy. Peptide nucleic acids (PNAs) are synthesized by attaching modified peptide backbones generally derived from repetitive N-2-aminoethyl glycine units in place of the regular phosphodiester backbone and represent synthetic impersonator of nucleic acids that offers an exciting research field due to their fascinating spectrum of biotechnological, diagnostic and potential therapeutic applications. The semi-rigid peptide nucleic acid backbone serves as a nearly-perfect template for attaching complimentary base pairs on DNA or RNA in a sequence-dependent manner as described by Watson-Crick models. PNAs and their analogues are endowed with exceptionally high affinity and specificity for receptor sites, essentially due to their polyamide backbone's uncharged and flexible nature. The present review compiled various strategies to modify the polypeptide backbone for improving the target selectivity and stability of the PNAs in the body. The investigated biological activities carried out on PNAs have also been summarized in the present review. � 2023 Elsevier Inc.
  • No Thumbnail Available
    Item
    DNA Origami-Templated Bimetallic Core-Shell Nanostructures for Enhanced Oxygen Evolution Reaction
    (American Chemical Society, 2022-04-15T00:00:00) Kaur, Gagandeep; Biswas, Rathindranath; Haldar, Krishna Kanta; Sen, Tapasi
    Hydrogen generation through electrocatalytic water splitting offers promising technology for sustainable and clean energy production as an alternative to conventional energy sources. The development of highly active electrocatalysts is of immense interest for improving the efficiency of gas evolution, which is strongly hindered due to the sluggish kinetics of oxygen evolution reaction (OER). Herein, we present the design of Ag-coated Au nanostar (core-shell-type Au@Ag nanostar) monomer structures assembled on rectangular DNA origami and study their electrocatalytic activities through OER, which remains unexplored. Our designed DNA origami-templated bimetallic nanostar catalyst showed excellent OER activity and high stability without using any external binder and exhibited a current density of 10 mA cm-2at a low overpotential of 266 mV, which was smaller than those of ss-DNA-functionalized Au@Ag nanostars and DNA origami-templated pure Au nanostars. Our results reveal that DNA origami-assembled core-shell Au@Ag nanostars show better electrocatalytic performance as compared to pure-core Au nanostars immobilized on DNA origami, owing to the presence of a highly conductive Ag layer. Such controlled assembly of bimetallic nanostructures on a DNA origami template can provide additional electrochemical surface area and a higher density of active sites resulting in enhanced electrocatalysis. � 2022 American Chemical Society. All rights reserved.
  • No Thumbnail Available
    Item
    Genomic DNA-mediated formation of a porous Cu2(OH)PO4/Co3(PO4)2�8H2O rolling pin shape bifunctional electrocatalyst for water splitting reactions
    (Royal Society of Chemistry, 2022-01-28T00:00:00) Singh, Harjinder; Ahmed, Imtiaz; Biswas, Rathindranath; Mete, Shouvik; Halder, Krishna Kamal; Banerjee, Biplab; Haldar, Krishna Kanta
    Among the accessible techniques, the production of hydrogen by electrocatalytic water oxidation is the most established process, which comprises oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Here, we synthesized a genomic DNA-guided porous Cu2(OH)PO4/Co3(PO4)2�8H2O rolling pin shape composite structure in one pot. The nucleation and development of the porous rolling pin shape Cu2(OH)PO4/Co3(PO4)2�8H2O composite was controlled and stabilized by the DNA biomolecules. This porous rolling pin shape composite was explored towards electrocatalytic water oxidation for both OER and HER as a bi-functional catalyst. The as-prepared catalyst exhibited a very high OER and HER activity compared to its various counterparts in the absence of an external binder (such as Nafion). The synergistic effects between Cu and Co metals together with the porous structure of the composite greatly helped in enhancing the catalytic activity. These outcomes undoubtedly demonstrated the beneficial utilization of the genomic DNA-stabilised porous electrocatalyst for OER and HER, which has never been observed. This journal is � The Royal Society of Chemistry.
  • No Thumbnail Available
    Item
    Combing of picogram level DNA equivalent to genomic DNA present in single human cell by self propelled droplet motion over a stable gradient surface
    (Academic Press Inc., 2023-11-08T00:00:00) Yadav, Hemendra; Algaonkar, Prashant S.; Chakraborty, Sudip; Ramakrishna, Wusirika
    DNA combing is a powerful technique for studying replication profile, fork-directionality and fork velocity. At present, there is requirement of a methodology to comb DNA present in a single human cell for studying replication dynamics at early embryonic stage. In our study, a surface having dual characteristics i.e., affinity towards negatively charged single DNA molecules and a hydrophobic gradient for self propelled droplet motion of combing solution was developed. The surface was made by coating of TCOS (trichloro-octylsilane) by vapor diffusion on APTES (Aminopropyl-triethoxysilane) coated glass slides. A gradient surface having high deposition efficiency (DE) was developed on which 5 picogram DNA equivalent to genomic DNA present in one single human cell can be combed. The gradient surface was thermostable in nature having the ability to sustain boiling temperature for two hours and sustain anisotropy in 70 % ethanol for 80 h. Applicability for multiple runs was enhanced such that the surface can be used for 13�14 times. Factors associated with gradient surface are unidirectional movement of combing solution droplet over the gradient surface for combing straight DNA molecules and a longer gradient surface of more than 1 cm such that long size DNA molecules can be combed. Ellipsometry and contact angle hysteresis confirmed the presence of hydrophobic gradient. XPS (X-ray photoelectron spectroscopy) and FTIR (Fourier Transform Infrared Spectroscopy) confirmed the presence of characteristic affinity towards negatively charged DNA molecules on the gradient surface. Combing solution was optimized for increasing deposition efficiency and for increasing the applicability of gradient surface for multiple runs. High temperature of combing solution was found to increase Deposition Efficiency. Combing solution was also optimized for combing single DNA molecules over the gradient surface. Single DNA molecules were combed by reducing pH and lowering concentration of triton-X in the combing solution. Dye: bp ratio was optimized for high fluorescent intensity and low surface background. � 2023 Elsevier Inc.