Ashish Kumar Singh

Biosensor based on ion selective electrode for detection of L-arginine in fruit juices

A biosensor has been developed for detection of L-arginine. The biosensor has been constructed using enzyme arginine deiminase as bio-component extracted from Pseudomonas putida MTCC 1313. The immobilization of enzyme was carried out in acrylamide gel, which was fixed onto the ion selective electrode. The optimization and kinetic characterization of free and immobilized enzyme was also studied. The response time of developed biosensor was found <30 s and a good linear range for arginine concentration from 1 to 10-9 M was shown. The developed biosensor was successfully applied for detection of arginine content in fruit juices.

Development of biological oxygen demand biosensor for monitoring the fermentation industry effluent.

A biosensor was developed for the determination of BOD value of fermentation industry effluent. The developed biosensor was fabricated by immobilizing the microbial consortium on cellulose acetate (CA) membrane in close proximity to a DO probe electrode. The microbial consortium was harvested from the fermentation industry effluent. The BOD biosensor was calibrated by using a solution containing the equivalent amount of glucose/glutamic acid (GGA) as a standard sample solution. The response time was optimized by immobilizing different concentrations of cell biomass on CA membrane. Once the response time was optimized, it was used for determination of BOD of fermentation industry effluent. For analysis of fermentation industry effluent, the response time was observed 7 minutes with detection limit 1 mg/L. Good linear range with GGA standard solution was observed, R 2 0.99 with relative standard deviation (RSD) <%. The observed BOD value by biosensor showed a good comparison with the conventional method for the determination of BOD.

L-arginine biosensors: A comprehensive review

Arginine has been considered as the most potent nutraceutics discovered ever, due to its powerful healing property, and its been known to scientists as the Miracle Molecule. Arginine detection in fermented food products is necessary because, high level of arginine in foods forms ethyl carbamate (EC) during the fermentation process. Therefore, L-arginine detection in fermented food products is very important as a control measure for quality of fermented foods, food supplements and beverages including wine. In clinical analysis arginine detection is important due to their enormous inherent versatility in various metabolic pathways, topmost in the synthesis of Nitric oxide (NO) and tumor growth. A number of methods are being used for arginine detection, but biosensors technique holds prime position due to rapid response, high sensitivity and high specificity. However, there are many problems still to be addressed, including selectivity, real time analysis and interference of urea presence in the sample. In the present review we aim to emphasize the significant role of arginine in human physiology and foods. A small attempt has been made to discuss the various techniques used for development of arginine biosensor and how these techniques affect their performance. The choice of transducers for arginine biosensor ranges from optical, pH sensing, ammonia gas sensing, ammonium ion-selective, conductometric and amperometric electrodes because ammonia is formed as a final product.

Sarcoma Excision and Pattern of Complicating Sensory Neuropathy

A potential complication of sarcoma excision surgery is a sensory neurological dysfunction around the surgical scar. This study utilised both objective and subjective sensation assessment modalities, to evaluate 22 patients after sarcoma surgery, for a sensory deficit. 93% had an objective sensory deficit. Light touch is less likely to be damaged than pinprick sensation, and two-point discrimination is significantly reduced around the scar. Results also show that an increased scar size leads to an increased light touch and pinprick deficit and that two-point discriminatory ability around the scar improves as time after surgery elapses. 91% had a subjective deficit, most likely tingling or pain, and numbness was most probable with lower limb sarcomas. Results also demonstrated that there were no significant relationships between any specific subjective and objective deficits. In conclusion, sensory disturbance after sarcoma surgery is common and debilitating. Efforts to minimize scar length are paramount in the prevention of sensory deficit. Sensation may also recover to an extent; thus, sensory reeducation techniques must become an integral aspect of management plans. Finally to obtain a comprehensive assessment of sensory function, both objective and subjective assessment techniques must be utilised.

Biosensor approaches to determination of L-arginine in foods and clinical samples

T cost constraints and needs in the point of care market require technology solutions that provide the sophistication for multiple analyte addition, quantitation and multiplexing, while offering a path to low cost high volume manufacture. Roll to roll processes provide low cost of manufacture at high volume and are currently used for glucose sensor manufacture. Yet proof of concept and development work is not suited to roll to roll processing because of tooling and set-up costs. In this paper, we discuss a batch process that provides the on-board microfluidic functions for complex assays, and which has the reliability and manufacturability to meet the need for low cost high volume manufacture.Understanding the physiology of body systems through in vivo distance and positional measurement in narrow enclosed spaces presents several major challenges. A technique using a 3-axis anisotropic magneto resistive (AMR) sensor array is reported which has been developed to provide continuous real-time monitoring of the position of the gastro-oesophageal squamo-columnar junction (SCJ) for the study of the pathology of the upper gastrointestinal (GI) tract. A technical review is provided of the AMR sensor array for the measurement of mm distances to provide positional information in vivo. The device is used to measure distance along a string of sensors relative to a small magnet that is endoscopically clipped on to the SCJ. The probe consists of an array of 32 sensors mounted on a flexible printed circuit board within a silicone tube and provides a total measurement distance of 217 mm.I this report, we utilized the nanopore single-molecule sensor to investigate a base-pair specific metal ion/nucleic acids interaction, and explored its potential application in locus-specific DNA methylation analysis. We identified that divalent Mercury ion (Hg21) can selectively bind a uracil-thymine mismatch (U-T) in a dsDNA. The Hg21 binding creates a reversible interstrand lock, called MercuLock, which enhances the hybridization strength by two orders of magnitude. Such MercuLock cannot be formed in a 5-methylcytosine-thymine mismatch (mC-T). By nanopore detection of dsDNA stability, single bases of uracil 5-methylcytosine can be distinguished. Since uracil is converted from cytosine by bisulfite treatment, cytosine and 59-methylcytosine can be discriminated. We have demonstrated multiple CpG methylation analysis in a p16 gene CpG island. This single-molecule assay may have potential in detection of epigenetic cancer biomarkers in biofluids, with an ultimate goal for early diagnosis of cancer.C neuroscientists study the electrical activity of large populations of neurons using arrays of extracellular microelectrodes (MEAs). Whereas this technology permits high density, simultaneous, long-term recording of extracellular field potentials, it is “blind” to sub threshold synaptic potentials generated by single cells and thus precludes the deciphering of large-scale processes of plasticity, learning and memory. Intracellular recordings of the full electrophysiological spectrum which includes sub threshold synaptic potentials, membrane oscillations and action potentials, are obtained only by the traditional sharpor patch-microelectrodes and are limited to single cells at a time and for short periods of time. Here, the development of novel arrays of protruding mushroom-shaped microelectrodes is presented. This neuro-electronic sensor is based on three converging cell biological principles: (1) the activation of endocytotic mechanisms by which the cultured cells are induced to actively engulf the protruding electrodes, (2) the tightening of the cleft between the cell’s membrane and the engulfed electrode, generating high seal resistance, and (3) the localization of ionic channels in the plasma membrane that faces the active region of the sensor. This technology merges the advantages of extracellular MEAs and intracellular microelectrodes and enables for the first time long-term, multi-site, parallel in-cell recording of intracellular sub threshold neuronal events. Further development and application of this sensing modality will help steer brain-circuit research toward previously uncharted territories.DNA computers use strands of DNA to perform computing operations. The computer consists of two types of strands – the instruction strands and the input data strands. The instruction strands splice together the input data strands to generate the desired output data strand. DNA computing holds out the promise of important and significant connections between computers and living systems, as well as promising massively parallel computations. Before these promises are fulfilled, however, important challenges related to errors and practicality has to be addressed. On the other hand, new directions toward a synthesis of molecular evolution and DNA computing might circumvent the problems that have hindered development, so far. This paper represent present and future DNA computer.L multilayer gratings are a new type of optical transducer based on fluid diffraction gratings on a surface. Tiny oil droplets regularly spaced at the wavelength of visible light function as diffraction gratings. When the liquid droplets interact with an analyte, droplet shape changes due to the interfacial forces involved, resulting in a detectable change in the intensity of light diffracted from the gratings. Using functional phospholipids as the oil enables specific detection of proteins in solution. The crucial property of the grating that allows detection is the lipid multilayer thickness, which must be controlled between ~10-100 nm. Methods for fabricating the gratings include dip-pen nanolithography and a new printing method that we call nanointaglio. The ability to integrate multiple different materials into sensor arrays opens the possibility for multiplexed sensing, and progress towards that goal will be presented.H probe which is composed of nucleic acid beacon with loop-stem structure is highly specific and sensitive. It can detect the results of numerous samples when fixed on carrier surface. However normal hairpin probe lacks a connecting arm which helps it to be fixed on the surface of a carrier as a result the fluorescence and quenching molecules are budged on their respective ends. So, by modifying, fixing and changing of complex electrochemical signal the stem arm can explore the hybridization response via fluorescence. We devised a new pattern of unsymmetrical ring hairpin probe that is simple and does not need the stem arm modification. This new pattern that do not has the markers of fluorescence and quenching molecules enables us to observe the signal of hybridization response using enzymatic colorimetric amplificatory affect. This technology has been used to detect genotype of Spoligotyping with drug-resistant tuberculosis. In the detection of genotype of Spoligotyping in 67 cases with drug-resistant tuberculosis, two genotypes namely Beijing and Non-Beijing family have been found in this region are 59.71% (40/67) and 40.29% (27/67) respectively. However, the percentage from the highest to the lowest order was resistant to streptomycin and isoniazid to rifampin.R studies indicated the role of ROS toward antibacterial activity. In our study we report ROS mediated membrane lipid oxidation of Escherichia coli treated with ZnO nanoparticles (NPs) as supported by detection and spectrophotometric measurement of malondialdehyde (MDA) by TBARS (thiobarbituric acid-reactive species) assay. The antibacterial effects of ZnO NPs were studied by measuring the growth curve of E. coli, which showed concentration dependent bacteriostatic and bactericidal effects of ZnO NPs. The antibacterial effects were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Further, antibacterial effect of ZnO NPs was found to decrease by introducing histidine to the culture medium treated with ZnO NPs. The ROS scavenging action of histidine was confirmed by treating histidine to the batch of Escherichia coli + ZnO NPs at the end of the lag phase of the growth curve (Set-I) and during inoculation (Set-II). A moderate bacteriostatic effect (lag in the E. coli growth) was observed in Set-II batch while Set-I showed no bacteriostatic effect. From these evidences we confirmed that the antibacterial effect of bare as well as TG capped ZnO NPs were due to membrane lipid peroxidation caused by the ROS generated during ZnO NPs interaction in culture medium.IT infrastructure viewed as an organizational core competency that is vital for organizations to survive and prosper in the current world. eLearning as a primary means of instruction is expanding significantly at educational level. However, most of the current educational institutions tend to emphasize on its benefits only. Students’ interactions, attention and communications are relatively low in the current LMS. Moreover, collaboration among learners themselves in real time is not supported by LMS. On the other hand, the growth of social networking sites (SNS) such as Facebook and others are also growing among today’s academy students. The main aim of this research is to suggest a model for eLearning, which might be adopted and used for educational institutions over the whole world. The focus of this new model will be on the process of integration of social networking platform (SNP) with LMS to overcome some of the restrictions of LMS.R oscillation has been observed in many super-conducting devices, in which the quantum behavior between atom and electromagnetic field interaction is established. In this paper, an average two-level transient atom within an optical adddrop filter is used, which is consequently generated by the AlGaAs material interaction with electromagnetic field in timedomain, which is modeled by a two branch microring circuit. The simulation results obtained have shown that the coupling intensity is affected to the output intensity oscillation and also directly affected to the Rabi oscillation frequency. The atom probability in the excited state of the device with the decreasing oscillation frequency at resonance is also calculated, The Rabi oscillation frequency in the range of terahertz is obtained. The change in Rabi frequency can be introduced after the external coupling to the device coupling ports, which can be calculated and formed for sensing application. By using the change in frequency shifting and interference fringe counter, new type interferometer can be established, which is available for atom/ molecule sensing applications. Such device can also be coated by material and formed as an atom/molecule antenna, which is useful for atom/molecule sensor, antenna and networks, which will be discussed in details.C has been the most fatal disease for last several decades. Some types of cancers remain silent at early stages and are usually diagnosed at advanced and incurable phases. Some other types result into poor survival rates owing to recurrence and metastasis. Early detection of cancer and non-intrusive approaches to monitor prognosis can have immediate and farreaching impacts on the lives of cancer patients. Diseases are initially expressed at molecular and cellular scales and identification of specific markers at such small scales would be a great step toward early detection. The study of biological molecules and diseased cells require sensing devices with molecular selectivity. Bio-nanotechnology and BioMEMs have proven promise to go down to the cellular/molecular scales with unprecedented selectivity. This talk will focus on recent advancements in fabricating nanoscale devices and nano-object mediated modalities that allow probing, detection and characterization of biological entities, their development and interactions. The state of the art in microfabrication and nanotechnology that has facilitated techniques to examine the presence or absence of particular disease biomarkers at molecular and cellular scale will be discussed. Some work done in my lab on the integration of biomedical engineering, nanoscience and nanotechnology, with particular focus towards their application in diverse areas like nanomanufacturing, molecular diagnostics, chip-based recognition of cancer cells and site-specific controlled drug delivery systems will be presented.