Publications by authors named "Lalit Bharadwaj"

Rationale: Chronic infection with in persons with cystic fibrosis (pwCF) has been linked to an increased risk of pulmonary exacerbations and lung function decline. We sought to establish whether baseline sputum microbiome associates with risk of incident infection and persistence in pwCF.

Methods: pwCF experiencing incident infections attending the Calgary Adult CF Clinic from 2010-2018 were compared with -negative sex, age (+/-2 years), and birth-cohort-matched controls.

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The persistent use of pesticides in the agriculture field remains a serious issue related to public health. In the present work, molecularly imprinted polymer thin films were developed using electropolymerization of pyrrole (py) onto gold microelectrodes followed by electrodeposition for the selective detection of chlorpyrifos (CPF). The molecularly imprinted polymer (MIP) was synthesized by the electrochemical deposition method, which allowed in-line transfer of MIP on gold microelectrodes without using any additional adhering agents.

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The uncontrolled use of organophosphate (OP) group of pesticides has led to their accumulation in food and vegetables, causing major health issues. Hence, the development of a reliable sensor is imperative for the detection of neurotoxic organophosphates (OP). In the present study, we have intertwined the interfaces of a Metal Organic Framework (MOF), MOF-directed rapid electrochemically grown gold nanorods (aAuNR), cysteamine (Cys) functionalization, and the neurotransmitter acetylcholinesterase (AChE) to fabricate a novel electrochemical bioprobe AChE/Cys/aAuNR/MOF/ITO for sensing OP pesticides with an ultra-low detection limit of 3 ng L-1 over a linear range of 30 to 600 ng L-1.

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We report the development of an ultrasensitive electrochemical sensor using polyaniline (PANi) and carboxyl functionalized multi-walled carbon nanotubes (fMWCNT) for the detection of organophosphates (OPs) in real samples. The sensor was tested in the linear concentration range of 10 ng/L to 120 ng/L. The limit of detection (LoD) was found to be 8.

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An Electrochemical micro Analytical Device (EµAD) was fabricated for sensitive detection of organophosphate pesticide chlorpyrifos in the food chain. Gold microelectrode (µE) modified with Zinc based Metal Organic Framework (MOF-Basolite Z1200) and Acetylcholinesterase (AChE) enzyme served as an excellent electro-analytical transducer for the detection of chlorpyrifos. Electrochemical techniques such as Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Differential Pulse Voltammetry (DPV) were performed for electrochemical analysis of the developed EµAD.

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Metal-organic frameworks (MOFs) are porous materials of recent interest due to their promising properties for technological applications. In this paper, the structure-property relationships of pristine and functionalized Zn-BTC (Zn(BTC)) MOFs are investigated. The results based on density functional theory (DFT) find that MOFs with coordinatively saturated secondary building units (SBU) are metallic, and MOFs with coordinatively unsaturated SBU are semi-conducting.

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Multi-walled-carbon nanotubes (MWNTs) are widely explored as carriers for drug delivery due to their facile transport through cellular membranes and are reportedly found to be effective against cancer. In the present study, we have evaluated cellular uptake of Docetaxel (DTX) conjugated MWNTs from human breast cancer cells (MCF-7 and MDA-mb-231) and have provided primary results on cytotoxicity of the same. Efficient internalization of the drug conjugate (DTX-MWNTs) inside the cell was corroborated with the help of confocal microscopy, transmission electron microscopy and flow cytometry.

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Glucose oxidase (GOD) immobilized long period grating (LPG) fibers have been proposed for the specific and sensitive detection of glucose. The treatment of LPG fibers with aminopropyl triethoxysilane has induced biding sites for the subsequent GOD immobilization. Field emission scanning electron microscopy, confocal laser scanning microscopy, infrared spectroscopy and Raman spectroscopy have provided detailed evidences about the effectiveness of the adopted biofunctionalization methodology.

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A facile method for controlling the density and site of attachment of gold nanoparticles onto the surface of carbon nanotubes is demonstrated. Nitric acid based oxidation was carried out to create carboxylic groups exclusively at the ends of carbon nanotubes, whereas oxidation using a mixture of nitric and sulfuric acid with varied reaction time was carried out to control the population of carboxylic groups on the side walls of nanotubes. In turn, 4-aminothiophenol modified gold nanoparticles were covalently interfaced to these carboxylated multi-walled carbon nanotubes in the presence of a zero length cross-linker, 1-ethylene-3-(3-dimethylaminopropyl) carbodiimide.

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Fluorescence-based molecular sensing and cellular imaging are commonly carried out with the application of organic dyes. Quantum dots (QDs) are now recognized as better tools because they are brighter, size tunable, and more photostable than dyes. Most of the proposed QD-based biosensing systems involve elements of known toxicity.

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The recovery of pure ZnO (zinc oxide) nanoparticles from spent Zn-Mn dry alkaline batteries is reported. Spent batteries were dismantled to separate the contained valuable metals of the cell electrodes in the form of black powder. Treatment of this black powder with 5 mol L(-1) HCl produced leach liquor, primarily containing 2.

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In this paper we explored the effect of copper sulphate on the morphology of actin filaments. Actin filaments attain different shapes and structure when exposed to 2mM concentration of copper sulphate. Lateral branches were observed after 4 h of incubation while shapes like Y- and V- were formed after 8h of incubation.

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The Nanorobotics and cargo transportation application of molecular motors is of recent intent. The present study explores the transportation of Mesalamine/5-aminosalicylic acid/5-ASA drug by molecular motors. Mesalamine is an anti-inflammatory drug used to treat Crohn's disease and ulcerative colitis.

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This article represents the effects on actin filaments attached to magnetic nanoparticles when exposed to low-intensity magnetic field. In this approach, streptavidin functionalized magnetic nanoparticles were used to demonstrate the alignment of actin filament under external magnetic field of 22mT. To check the directionality of myosin on magnetically aligned actin filaments in vitro motility assay was performed with myosin and average velocity was found to be 3.

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Dispersion of carbon nanotubes (CNTs) is a challenging task for their utilization in nanoscale device applications. This account reports a comparative analysis on dispersion of multiwalled carbon nanotubes (MWNTs) with four surfactants-Triton X-100, Tween 20, Tween 80, and sodium dodecyl sulfate (SDS). Among the four surfactants, Triton X-100 and SDS provide maximum and minimum dispersion, respectively.

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In this manuscript, a new strategy has been reported for circumscribed covalent attachment of barbed and pointed ends of actin filaments to polystyrene beads. A comparative study of attachment of actin filaments to polystyrene beads was performed by blocking functionally active sites on polystyrene beads with nonionic detergents such as Tween 20, Tween 80 and polyethylene glycol (PEG). Effective blocking of active sites was obtained with Tween 80 at 0.

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In the present manuscript, we report the studies and observations for chemical interference due to aggregates formation during covalent immobilization of thiolated lambda-DNA between gold microelectrodes. Dip and Drop approaches were employed to study DNA immobilization using thiolated oligos (oligoA 5' GGGCGGCGACCT 3' and oligoB 5' AGGTCGCCGCCC 3'). As a result of aggregation, less interference was observed in Dip approach as compared to Drop approach.

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We report an important observation that the surface conductivity of antibody layer immobilized on polylysine-coated glass substrate decreases upon the formation of complex with their specific antigens. This change in conductivity has been observed for both monoclonal and polyclonal antibodies. The conductance of monoclonal mouse IgG immobilized on polylysine-coated glass substrate changed from 1.

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1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) was tested for interference with the Lowry method of protein determination. The EDC interference was nearly additive at both 660 and 750 nm. Blue-colored complex developed in the case of EDC and showed maximum absorbance at 750 nm, similar to the bovine serum albumin (BSA) estimation.

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DNA and electronics seem to be two different things, but a series of events has highlighted the unusual ability of DNA to form electronic components

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