Ramakrishnan Ganesan

Ramakrishnan Ganesan
BITS Pilani, Hyderabad · Department of Chemistry

PhD

About

85
Publications
18,952
Reads
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1,174
Citations
Additional affiliations
February 2012 - present
BITS Pilani, Hyderabad
Position
  • Professor (Assistant)
January 2010 - January 2012
Agency for Science, Technology and Research (A*STAR)
Position
  • Researcher
April 2008 - January 2010
Helmholtz-Zentrum Hereon
Position
  • Scientific Employee

Publications

Publications (85)
Article
Contrary to the long-standing opinion of boronic acids being typically reactive with 1,2- and 1,3-diols and hence not suitable for quantitative sensing of DNA containing only a mono-ol unit, this proof-of-concept study has successfully shown the feasibility to quantitatively detect DNA in the concentration range of 5 to 50 nM plausibly through boro...
Article
Full-text available
We report a low-temperature magneto transport study of Bi2Se3 thin films of different thicknesses (40, 80 and 160 nm), deposited on sapphire (0001) substrates, using radio frequency magnetron sputtering technique. The high-resolution x-ray diffraction measurements revealed the growth of rhombohedral c-axis {0003n} oriented Bi2Se3 films on sapphire...
Article
Full-text available
Background: Metal-containing resists entered the mainstream semiconductor industry process flow to mitigate the low absorbance of extreme ultraviolet (EUV) radiation by thin films of organic resists that lead to poor sensitivity and their inability to handle rigors of development and etching conditions. Aim: The long and rich history of using met...
Article
Owing to the alarming consequences of antimicrobial resistance, the requirements for effective antimicrobial materials working under dark and visible-light conditions are on the high rise. On a different note, heterojunctions between semiconductors are highly desirable to enhance the photocatalytic activity of the individual components in a synergi...
Article
In the current study, lipase from Bacillus subtilis was covalently immobilized over magnetite nanoparticles and employed for biofuel generation from food waste such as used olive oil. The free and immobilized lipases have been tested to optimize reaction temperature and pH parameters to determine the specific activity using p-nitrophenyl palmitate....
Article
Nucleic acid tests (NATs) have gained an important position in biosensing in the context of the increasing need to meet the stringent requirements for accurate diagnosis of infectious diseases with high sensitivity and selectivity. Recently, the development of new strategies towards multiplex detection of analytes in a single assay is gaining impet...
Preprint
Full-text available
Evaluation of the defect levels in low-dimensional materials is an important aspect of quantum science. In this article, we report a facile synthesis method of hexagonal boron nitride (h-BN) and evaluate the defects and their light emission characteristics. The thermal annealing procedure is optimized to obtain clean h-BN. The UV-Vis spectroscopy s...
Article
Thin films of Bi2Se3 were deposited on Si (100) substrates using RF magnetron sputtering at a deposition temperature of 633 K. The surface morphology of Bi2Se3 films revealed the variation of grain sizes with thickness, while elemental analysis showed the stoichiometric Bi2Se3 films. The high-intensity x-ray diffraction peaks along (0003), (0006) a...
Article
Caffeic acid (CA) is a naturally occurring plant-derived polyphenol possessing diverse biological properties. However, the poor water-solubility of CA restricts its widespread applications. On the other hand, biogenic amines such as spermine and spermidine are natural constituents in eukaryotes. In this work, we present water-soluble complexes of C...
Article
Despite the highly potent biological characteristics, the poor water-solubility of caffeic acid (CA) limits its applications in various domains. Here, we present a facile approach, wherein CA has been treated with dopamine hydrochloride (Dopa.HCl) to obtain a water-soluble acid-base complex, which does not possess any covalent bond between the indi...
Article
Full-text available
Gold nanoparticles (Au NPs) based technology has been shown to possess enormous potential in the viral nucleic acid diagnosis. Despite significant advancement in this domain, the existing literature reveals the diversity in the conditions employed for hybridization and tagging of thiolated nucleic acid probes over the Au NPs. Here we employ the pro...
Article
We report a solid-state synthesis of [email protected]3N4 core-shell nanocomposites, in which melamine—a precursor of graphitic carbon nitride (g-C3N4)—is thermally decomposed over a pre-formed ZnO core. The thermolysis has led to the formation of a nitrogen-deficient carbonaceous shell over the ZnO core—reported for the first time—when the g-C3N4...
Article
Owing to the probiotic origin, lipases-derived from the Lactobacilli sp. are considered to be promising biomaterials for in vivo applications. On a different note, poly(ε-caprolactone) (PCL)—an FDA-approved polymer for implantable applications—lacks inherent antimicrobial property, because of which suitable modifications are required to render it w...
Article
Molecular diagnosis of viral genotyping devoid of polymerase chain reaction (PCR) amplification in clinical cohorts has hitherto been challenging. Here we present a simplified molecular diagnostic strategy for direct genotyping of hepatitis C virus (HCV) 1 and 3 (prevalent worldwide) using a combination of rationally designed genotype-specific anti...
Article
The synthesis of exotic nanocomposites (NCs) comprising of highly dispersed metal sulfides is challenging owing to the formation of crystalline sulfides in the conventional wet-impregnation method and sublimation characteristics of the sulfide precursors in the thermal decomposition method. Here, we employ silver amyl xanthate (Ag-Xn) precursor to...
Article
We report the catalytic enhancement of hydrogen generation by 1) in situ Fe (0) formed and 2) nitroarenes substrates during Fe3O4@Pd core-shell nanoparticles catalyzed tandem reaction. The active hydrogen species are generated in Pd shell, which either combine to form H2 gas or take part in relatively faster nitroarene reduction reaction. The rate...
Article
Increasing incidence of Hepatitis C viral (HCV) infection worldwide is a major concern for causing liver cirrhosis and hepatocellular carcinoma, leading to increased morbidity and mortality. Currently, the prevalence of HCV infection is estimated to be in the range of ~3%. According to the World Health Organization, antiviral drugs can cure more th...
Article
Full-text available
Increasing the surface area-to-volume ratio of materials through size reduction is a desired approach to access maximum possible surface sites in applications such as catalysis. However, increase in the surface energy with the decrease in dimension warrants strong ligands to stabilize nanosystems, which mask the accessibility of the active surface...
Article
Studies on photocatalytic activity of monophasic and biphasic TiO2 have been well explored. However, detailed studies on the photocatalytic activity of triphasic titania, as opposed to monophasic or biphasic TiO2 are scarce. Here we report a comparative structure-sensitive photocatalytic study of triphasic versus anatase TiO2, both have been synthe...
Article
Molybdenum disulfide (MoS2) is traditionally grown at a high temperature and subsequently patterned to study its electronic properties or make devices. This method imposes severe limitations on shape and size of MoS2 crystals that can be patterned precisely at required positions. Here we describe a method of direct nanoscale patterning of MoS2 at r...
Article
Establishing an endothelial cell (EC) monolayer on top of the blood contacting surface of grafts is considered to be a promising approach for creating a hemocompatible surface. Here we utilized the high affinity interactions between the EC plasma membrane expressed enzyme called endothelin converting enzyme-1 (ECE-1) and its corresponding substrate...
Article
Lipases from various origins such as fungi and bacteria have been largely explored for various applications including biofuel production. Keeping the environmental and health concerns into consideration, we employed lipases derived from probiotic sources like L. plantarum and L. brevis for biodiesel production from the gold standard fresh and used...
Article
Full-text available
The presence or absence and nature of the free patchy ends in DNA sequences has a decisive effect on the performance of colorimetric sensors based on the use of gold nanoparticles (Au NPs). The authors have designed two unmodified gene probes (probe 1: a 19-mer; probe 2: an 18-mer). They are complementary to either half of a 37-mer target derived f...
Article
Ag-Au alloy microflower substrates with tunable surface compositions are prepared through simple thermolysis of metal-alkyl ammonium halide precursors for probing the role of surface composition in SERS. The bulk and surface composition of the microflowers are characterized using ED-XRF and XPS analyses, respectively. For alloys, the ED-XRF studies...
Article
Full-text available
Solvent-less synthesis of nanostructures is highly significant due to its economical, eco-friendly and industrially viable nature. Here we report a solid state synthetic approach for the fabrication of Fe3O4@M (where M = Au, Ag and Au-Ag alloy) core-shell nanostructures in nearly quantitative yields that involves a simple physical grinding of a met...
Article
Full-text available
Enzyme-embedded polymer degradation was reported to be an attractive alternative approach to the conventional surface pouring method for efficient degradation of polymers using fungal-derived enzyme Candida antarctica lipase B. Despite the enormous potential, this approach is still in its infancy. In the present study, a probiotic lipase obtained f...
Article
Full-text available
The microbial resistance to different drugs due to excessive usage of antibiotics in various domains has become a serious environmental threat in recent years. This gave the impetus to researchers to find alternatives that do not lead to multi-drug resistant microbes. In this backdrop, silver nanoparticles (Ag NPs) have become a popular choice due...
Article
Background: Gold nanoparticles (GNPs) are key diagnostic and therapeutic agents in biomedical sciences. Several studies have been carried out in different therapeutic areas such as in cancer treatment, antibacterial topical agents, imaging agents etc. There is a necessity to evaluate the gold nanoparticles cytotoxicity at all fronts. Since blood i...
Article
Owing to the eco-friendly nature of biomolecules, there lies a huge interest in exploring them as capping agents for nanoparticles to achieve stability and biocompatibility. Lipase extracted from the probiotic Lactobacillus plantarum is utilized for the first time to study its efficacy in capping gold nanoparticles (GNPs) in the room temperature sy...
Article
Full-text available
UV-nanoimprint lithography (UV-NIL) is a promising technique for direct fabrication of functional oxide nanostructures. Since it is mostly carried out in aerobic conditions, the free radical polymerization during imprinting is retarded due to the radical scavenging ability of oxygen. Therefore, it is highly desirable to have an oxygen-insensitive p...
Conference Paper
Full-text available
Imparting stability to the nanofluids is important for various applications, including heat-exchange. In the present study, aluminum oxide (Al2O3) nanoparticles of size 80 nm are anchored with PEG (poly(ethylene glycol) methyl ether) with the help of a silane ((3-chloropropyl) trimethoxysilane) linker. The process adopted here is a two-step reactio...
Article
Full-text available
It is a subject of exploration whether the phase pure anatase or rutile TiO2 or the band alignment due to the heterojunctions in the two polymorphs of TiO2 plays the determining role in efficacy of a photocatalytic reaction. In this work, the phase pure anatase and rutile TiO2 have been explored for photocatalytic nitroarenes reduction to understan...
Article
Photocatalytic reduction of aqueous nitrate has been thoroughly studied over noble metals doped and pristine TiO2synthesized by a customized single step microwave assisted hydrothermal method. The synthesized catalysts are systematically characterized using XRD, Raman spectroscopy, FE-SEM, HR-TEM, XPS, diffuse reflectance spectroscopy, and PL measu...
Article
A polymerizable sol-gel approach has been employed to synthesize bulk and nano-crystalline WO3. A W-containing sol-gel resin is formed and subjected to thermally induced free radical polymerization followed by calcination at 450, 650 and 850 °C. TGA analysis was performed to reveal the calcination temperature required for WO3 formation. The synthes...
Article
Researchers debate on if it is only the crystalline properties of TiO2 or also the surface morphology and even optical properties of different types of TiO2 are the instrumental parameters on photocatalysis. It is a subject of exploration whether the phase pure anatase TiO2 or the heterojunctions and band alignment in the two polymorphs of TiO2(ana...
Article
Nanostructures of metal sulfides are conventionally prepared via chemical techniques and patterned using self-assembly. This poses a considerable amount of challenge when arbitrary shapes and sizes of nanostructures are desired to be placed at precise locations. Here we describe an alternative approach of nanoscale patterning of zinc sulfide (ZnS)...
Article
Full-text available
Palladium is one of the widely used precious metals toward catalysis, energy, and environmental applications. Efficient recovery and reusability of palladium from the spent catalysts is not only highly desirable for sustainable industrial processing but also for preventing environmental contamination. Here, we present a facile citrate-mediated amin...
Article
Recently, polymerizable sol–gel approach has been emerged as a potential route to synthesize supported catalytic oxides and also to fabricate nanostructures. However, this approach has been limited only to liquid metal-alkoxide precursors as the polymerizable precursor has to be in liquid form consisting of homogeneously dissolved metal-alkoxide an...
Article
Polymer degradation through lipase appears to be an enthralling alternative to bulk chemical routes. Poly (ε-caprolactone) (PCL) is an artificial polyester that can be degraded by microbes and enzymes like lipases and esterases. The environmental degradation of PCL is dependent on the activity of bacteria that characterization techniques such as th...
Article
Core-shell type Fe3O4@Fe2O3 was dispersed over nano Al2O3 support using aqueous medium co-precipitation method. The Fe3O4 core offers magnetic recoverability, while the shell Fe2O3, due to its optimal band gap, provides photocatalytic activity in the visible light region. The concentration of Fe3O4@Fe2O3 was varied and the synthesized materials wer...
Article
In the era of increasing usage of materials, there is a growing concern of environmental aspects. This has motivated many scientists to research on greener materials and technologies. In this line, several biodegradable materials and biomolecules-based technologies have been developed in the recent years. This has triggered vivacious participation...
Article
Direct imprinting of metals is predominantly achieved by using polydimethylsiloxane (PDMS) molds to pattern metal nanoparticles and subsequently melting them to form continuous structures. Although such a combination can successfully imprint metals, the yield and reproducibility are usually low when sub-100 nm features over large areas are desired....
Article
TiO2 synthesized by polymerizable sol–gel approach is used to demonstrate the photoreduction of Cr(VI) in aqueous medium. Fe3O4 is chosen as the magnetically recoverable support, onto which, 10, 20, 30 and 50% of TiO2 have been dispersed following the polymerizable sol–gel approach. All the synthesized materials are characterized using XRD, SEM, di...
Article
Photocatalytic valorization of harmful pollutants like nitroarenes to important intermediates like aminoarenes has been carried out with the help of TiO2 supported zeolite-4A catalyst, synthesized by polymerizable sol-gel route. A series of solvents such as water, primary and secondary alcohols have been studied for their role on photocatalytic red...
Article
A polymerizable sol–gel method has been employed to synthesize tailored TiO2 supported zeolite-4A. The synthetic procedure was optimized by using FTIR, TGA and DSC to prepare various TiO2 loading ranging from 10 to 30 wt% on the support. The as-synthesized materials were characterized thoroughly with powder XRD, SEM, UV–Vis spectroscopy and BET sur...
Article
Moth's eye inspired multi-scale ommatidial arrays offer multi-functional properties of great significance in optoelectronic devices. However, a major challenge remains in fabricating these arrays on large-area substrates using a simple and scalable technique. Here we present the fabrication of these multi-scale ommatidial arrays over large-areas by...
Article
Full-text available
After the cost of ownership of tool, the next significant cost involved in nanoimprint lithography is that of mold fabrication. The cost of mold fabrication is proportional to the area of pattern and follows an inverse relationship with the pattern resolution. In this work, the authors demonstrate proof-of-concept fabrication of Si and SiO 2 gratin...
Article
Step-and-flash imprint lithography (S-FIL) is a wafer-scale, high-resolution nanoimprint technique capable of expansion of nanoscale patterns via serial patterning of imprint fields. While S-FIL patterning of organic resins is well known, patterning of metal-organic resins, followed by calcination to form structured oxide films remains relatively u...
Article
Selective surface immobilization of multiple biomolecule components, under mild conditions where they do not denature, is attractive for applications in biosensors and biotechnology. Here, we report on the biocompatible and pH-responsive photoresist containing diazoketo-functionalized methacrylate, methacrylic acid, and poly(ethylene glycol) methac...
Article
Direct patterning of oxides using thermal nanoimprint lithography is performed using either the sol-gel or methacrylate route. The sol-gel method results in resists with long shelf-life, but with high surface energy and a considerable amount of solvent that affects the quality of imprinting. The methacrylate route, which is limited to certain oxide...
Article
Full-text available
Self-assembly of block copolymers has been identified as a potential candidate for high density fabrication of nanostructures. However, the factors affecting its reliability and reproducibility as a patterning technique on various kinds of surfaces are not well-established. Studies pertaining to block copolymer self-assembly have been confined to u...
Article
Full-text available
Nanostructuring of Al₂O₃ is predominantly achieved by the anodization of aluminum film and is limited to obtaining porous anodized aluminum oxide (AAO). One of the main restrictions in developing approaches for direct fabrication of various types of Al₂O₃ patterns, such as lines, pillars, holes, etc, is the lack of a processable aluminum-containing...
Article
Although step-and-flash imprint lithography, or S-FIL, has brought about tremendous advancement in wafer-scale fabrication of sub-100 nm features of photopolymerizable organic and organo-silicon-based resists, it has not been successful in direct patterning of inorganic materials such as oxides because of the difficulties associated with resist for...
Article
Micropatterns of proteins were created by using patterned ion beam irradiation onto a polyethylene film and graft polymerization of acrylic acid. Acrylic acid was selectively graft polymerized on the irradiated regions. The results of the grafting study revealed that the optimum fluence to achieve the maximum grafting degree was 1 × 1015 ions/cm2....
Article
Full-text available
The use of polymerization to solidify, strengthen and imprint liquid organic materials is the basis of ultraviolet (UV) nanoimprint lithography. In spite of these advantages, the use of polymerization to pattern materials in thermal nanoimprint lithography is almost non-existent. In this study, we demonstrate a facile and general method to directly...
Article
Two novel monomers, containing diazoketo functional groups, cholic acid 3-diazo-3-ethoxycarbonyl-2-oxo-propyl ester methacrylate (CDEOPE-MA) and 2-diazo-6-hydroxy-3-oxo-hexanoic acid ethyl ester methacrylate (DHOHEE-MA), were designed and synthesized for biomolecular patterning applications. The polymers were synthesized by radical copolymerization...
Article
Full-text available
Micro- and nano-scale protein patterns have gained significant technological interest. While certain techniques for single-component proteinpatterning are well-established, multicomponent proteinpatterning approaches are a current topic of intensive research, which might enable complex biosensor systems and expand the knowledge in protein-protein a...
Article
Surface grafting of photosensitive polymer brushes on a flexible polymer surface was performed using Ar ion irradiation, which generated peroxides on the polymer surface upon exposure to air. These peroxides were utilized as initiators for graft polymerization of a photosensitive diazoketo-functionalized methacrylate monomer. Upon UV light exposure...
Article
A new method for biomolecular patterning based on ion irradiation-induced graft polymerization was demonstrated in this study. Ion irradiation on a polymer surface resulted in the formation of active species, which was further used for surface-initiated graft polymerization of acrylic acid. The results of the grafting study revealed that the surfac...