Publications by authors named "Jose S Melo"

Biohybrids (a combination of biological material and inorganic nanoparticles) offer a number of advantages like improved functionality over conventional materials.Thus, to understand the practical application of biohybrids as drug carriers, a biohybrid drug carrier of colloidal silica nanoparticles (NP)-sodium alginate loaded with doxorubicin (Dox-biohybrid) was synthesized by evaporation induced self-assembly (EISA) using spray drying technique. Further, the morphology, size and interactions between various components of the biohybrid were studied through SEM, DLS and FTIR techniques.

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With the advent of nanotechnology there has been an impetus towards sol gel encapsulation of biocatalyst in mesoporous silica. In this study cells of Streptococcus lactis expressing β-galactosidase activity were entrapped in silica microcapsules using evaporation induced assembly through spray drying technique. These microcapsules were characterized using complementary techniques of electron microscopy and neutron/X-ray scattering.

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For efficient utilization of immobilized invertase enzyme, a novel bio-hybrid support comprising silica nanoparticles and Ocimum basilicum seed was synthesized. Ocimum basilicum seeds provide a natural fibrouspellicular structure which acts as template for assembly of silica nanoparticles. Bio-hybrids of two different morphologies have been obtained by changing the physico-chemical conditions of the assembly process.

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Pityrogramma calomelanos (L.) Link, popularly known as "Silver fern" has significant importance as a medicinal plant used traditionally for its astringent, analgesic, anti-haemorrhagic, anti-hypertensive, anti-pyretic and anthelminthic properties. This fern demonstrates an increased morphogenetic potential towards sporophyte formation, upon exposure to low doses of gamma radiation.

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The previously developed Sphingomonas sp. based optical microplate biosensor for methyl parathion (MP) was good as it detected multiple samples but had poor stability and low sensitivity. The present study aims to overcome these limitations.

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This manuscript reports a new approach for the synthesis of one dimensional gold nanostructure (AuNs) and its application in the development of cholesterol biosensor. Au nanostructures have been synthesized by exploiting β-diphenylalanine (β-FF) as an sacrificial template, whereas the Au nanoparticles (AuNPs) were synthesized by ultrasound irradiation. X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy dispersive analysis of X-rays (EDAX) have been employed to characterize the morphology and composition of the prepared samples.

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Naturally available low cost materials have gained importance as effective alternative to conventional sorbents for the removal of metal ions from water. The present study describes the use of black hair waste as a sorbent for the removal of uranium ions from an aqueous medium. Alkali treatment of the biomass resulted in a significant increase in its uptake capacity.

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Developing a biosensor which is capable of simultaneously monitoring l-Dopa levels in multiple samples besides requiring small reaction volume is of great value. The present study describes the detection of l-Dopa using tyrosinase enzyme extracted from Amorphophallus campanulatus and immobilized on the surface of the microplate wells. Among the different approaches used for immobilizing tyrosinase onto the microplate wells, glutaraldehyde treatment was found to be most effective.

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In this paper, a simple and innovative electrochemical hydrogen peroxide biosensor has been proposed using catalase (CATpp) derived from Pichia pastoris as bioelectrocatalyst. The model biocomponent was immobilized on gold nanoparticle nanotubes (AuNPNTs) and polythiophene composite using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide (EDC-NHS) coupling reagent. In this present work, we have successfully synthesized gold nanoparticles (AuNPs) by ultrasonic irradiation.

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Bio-polymeric mosquitocidal formulations were developed for the control release of Bacillus sphaericus ISPC-8 by the immobilization of its spore-crystal complex onto the macroporous polymeric matrices. The biodegradable formulations were synthesized at sub-zero temperature using natural polymeric substrates like agarose, alginate, cellulose, non-adsorbent cotton, wooden cork powder and also magnetite nanoparticles. The obtained polymeric matrices were morphologically characterized, which showed 85-90% porosity, uniform pores distribution, high permeability and controlled degradation (19-30%) in 4 weeks depending upon the composition of formulations.

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An assembled microstructure of silica nanoparticles and Streptococcus lactis (S. lactis) cells has been synthesized by evaporation induced self assembly, with the objective of its application in bioremediation. Different morphologies have been realized by tuning the physico-chemical conditions of the assembly process.

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Limitation of conventional techniques for the removal of heavy metals present at low concentrations, has led to the need for developing alternate technologies like biosorption. In the present study we describe the use of melanin pigment synthesized through green technology, for sorption of uranium from aqueous system. Biosynthesized melanin showed good uptake over a broad pH range.

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This study presents a novel development of a floating polymeric-magnetite cryobead for the recovery of hexavalent uranium from the aqueous sub-surfaces. The alginate-agarose-magnetite cryobeads were synthesized by the process of cryotropic-gelation at subzero-temperature. The physico-chemical properties of cryobeads showed high surface area and high interconnected porosity (≈ 90%).

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Cholesterol oxidase (ChOx) and cholesterol esterase (ChEt) have been covalently immobilized onto functionalized graphene (FG) modified graphite electrode. Enzymes modified electrodes were characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). FG accelerates the electron transfer from electrode surface to the immobilized ChOx, achieving the direct electrochemistry of ChOx.

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Graphene is chemically synthesized by solvothermal reduction of colloidal dispersions of graphite oxide. Graphite electrode is modified with functionalized-graphene for electrochemical applications. Electrochemical characterization of functionalized-graphene modified graphite electrode (FGGE) is carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS).

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Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) has been reported from the Americas, Africa and Asia, often in association with Aceria guerreronis Keifer (Acari: Eriophyidae), one of the most important pests of coconut (Cocos nucifera L.) in different parts of the world. That phytoseiid has been considered one of the most common predators associated with A.

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