The need to measure human motion and to estimate its kinematic and dynamic parameters in a real time appears in many fields such as medicine, sport, art and entertainment. This publication describes, inexpensive and easy to customize for many applications, Inertial Motion Capture Costume. The costume is based on IMU sensors and includes industry grade software that enables acquisition, visualization and analysis of human motion data.
The main objective of this article is to demonstrate by performing simulation measurements of biosensor that can detect the presence of pathogens through simultaneous mass and impedance techniques. This biosensor merges two biosensing techniques namely resonant frequency measurements and electrochemical impedance spectroscopy (EIS) on a single biosensor. Parallel measurements provide better sensitivities, have higher diagnostics accuracy and reduce the risk of false positives. Low cost, high resolution screen printing technology was used to fabricate the microelectromechanical array of μTAS on flexible piezoelectric substrates. The basic biosensor framework includes a substrate that highly sensitive sensor like thickness shear mode and immunosensor can be fabricated using quartz crystal lattice that integrated with electrochemical sensor [1]. The quartz crystal microbalance is a label free technique, which minimizes interference with the interaction being studied. A piezoelectric device is portable, simple and cost effective, and is suitable for real-time monitoring of biospecific interactions such as antigen-antibody, receptor ligand, and enzymes-substrate interactions with high sensitivity and specificity. For instance, the biological mixtures such as antibodies are capable of binding to terminal active functional groups (i.e., COOH, OH and NH2) of self-assembled monolayers (SAM) and immunocapture antigens such as glycoproptien or other targets[2]. The QCM can consequently detect mass changes due to these molecular interactions on the surface of the QCM. The top and bottom circular excitation electrodes with 150um diameter were modeled as gold (Au) films of 16 μm thickness. A sinusoidal voltage with amplitude of 5 mV was applied across the quartz crystal. Figure 1 shows the principle of integrated biosensors which gold electrodes were printed on both sides of a thin 500um quartz layer to form the quartz crystal microbalance (QCM)-impedance device. The silver (Ag) semicircular counter electrode was modeled around the top working electrode on the same area of the quartz crystal for performing the electrochemical impedance spectroscopy (EIS) experiments for detection of bacteria (E-Coli) and the results were compared to quartz crystal microbalance measurements. Furthermore, the use of gold surface can be incorporated into the transducer compatible with the biological samples such as use of highly specific monoclonal antibodies, and incorporation of amplification step to maximize the signal detection. In general, the quartz crystal is traditionally considered to be a mass sensitive sensor that produces response which it changes its resonance frequency to different thin film samples or liquids in contact with it surface. For a straight relationship between a thin film mass of the order of nanograms, the quartz crystal response will be of of the order of Hertz according to Eq. 1, Sauerbrey Equation [3]. ρ
The field of medical engineering with high standards for implantable applications requires frequently not only sensitive measuring systems but also long term stability and less inflammatory reactions after implantation. Implantable electronics relies on a hermetic and dissolvent consistent encapsulation. Already used materials, such as parylene C, have excellent barrier properties, protect from corrosion and show good bio-stability. But, the biocompatibility of such materials is often insufficient. The in this work described encapsulation with a special coating of polyethylene glycolated amino acids could improve this. The better cell compatibility as well as the protein repellent behaviour and the changes in surface characteristics implies that this coating enhances the functionality and biocompatibility in general. This encapsulation is of current interest for an implantable blood glucose measuring system based on the piezoresistive pressure sensor chip containing a glucose-sensitive hydrogel in its cavity.
Despite of increasing the food production by application of pesticides, the wide use of them can lead to environmental pollution and their residues in food. Due to the increasing application of pesticides, reliable and accurate analytical methods are necessary to analyze different occupational and environmental samples like air, water, soil, as well as also food containing these compounds. There are some traditional techniques to determine the pesticides such as liquid chromatography and gas chromatography with electron capture detection. The mentioned techniques are very expensive and a well-equipped laboratory and well-trained analysis operators are required. A sample pre-treatment step is needed to determine the analytes at ppb levels. Therefore, in the last few years many sensitive, selective, and accurate methods have been developed to determine the trace toxic species like pesticides. Electrochemical sensors are the appropriate and interested devices to monitor the trace and even ultra-trace pesticides. Molecular imprinted polymers (MIPs) can be used as recognition elements or modifying agents in sensors structure to increase their selectivity and improve their response. Recently, modified electrode by different modifying agents like MIPs and various nano structures are being used for quantification of analytes because of their interesting advantages. Modified electrodes may be used in combination with different electrochemical techniques. The aim of this study was to synthesize a molecularly imprinted polymer for dicloran for first time and then to apply it as a recognition element in the nano-composite carbon paste electrode for selective and sensitive electrochemical determining the dicloran pesticide in environmental and biological samples.
Multi-walls carbon nanotubes (MWCNTs) and a molecularly imprinted polymer (MIP) were used as the modifiers in senor composition. A dicloran selective MIP and a non-imprinted polymer (NIP) were synthesized and applied in the carbon paste electrode. To prepare the bare carbon paste electrode (CP), graphite, MWCNT and paraffin oil were mixed. The MIP-CP and NIP-CP were prepared by mixing different percentages of graphite, MWCNT, paraffin oil, and MIP or NIP. This mixture was homogenized and final paste was packed into the end of an electrode body. After the optimization of electrode composition, it was used to extract the analyte in the sample and then was inserted in the electrochemical cell to determine the concentration of extracted analyte. Some parameters affecting the sensor response were optimized in the extraction and analysis steps, such as sample pH, electrolyte concentration and pH, stirring rate of analyte solution, as well as the instrumental parameters of square wave voltammetry (square wave amplitude and frequency, deposition potential and its exertion time, and electrolyte concentration).
We introduce a nanofluidic mixing device entirely fabricated in glass for the fluorescence detection of single molecules. The design consists of a nanochannel T-junction and allows the continuous monitoring of chemical or enzymatic reactions of analytes as they arrive from two independent inlets. The fluorescently labeled molecules are tracked before, during and after they enter the mixing region, and their reactions with each other are observed by means of optical readout such as Förster Resonance Energy Transfer (FRET). Our method can be used for analyzing the kinetics of DNA annealing in a high-parallelized fashion.
Cancer is a serious global health problem, which resulted in 8.2 million deaths in 2012 alone. Amongst different types of cancer, lung cancer is the most lethal and contributes 19.4% of cancer deaths. Better disease-free cancer survival rates have been reported when surgery is followed by systemic chemotherapy. Efficient treatment can be achieved through personalized chemotherapy dosage whereby optimum treatment is given to kill the cancer the side effects are minimized. Here, we present a microfluidic concentration gradient device for toxicity studies on lung cancer cell lines (A549). Automated drug dilution is achieved by simply tuning the flow rate and geometries of the microfluidics network. Sets of tree-like-concentration-generators were designed to achieve constant flow rate at each outlet by optimizing the channel lengths. Serpentine structures were placed in the middle in the middle and at each outlet channel to the design to improve mixing along the channel. The lengths of middle and outlet channels are varied from 1.5 mm to 12 mm to obtain sufficient mixing of two fluid flows. Theoretically, correlations between hydraulic flow and electrical circuit equations analogy were applied to ease the microfluidic design process. Later, 3D (dimensional) simulations using computational fluid dynamic (CFD)-based simulator, i.e. Ansys FLUENT were performed by implementing species transport method prior to fabrication. The simulation process helps to demonstrate the effect of varying channel length on the velocity magnitude and the concentration of the microfluidic structure. In addition, the simulation results allows us predict the fluid flow velocity that showed constant velocity magnitude at each outlet. Wider range of dilution can be achieved, when a higher number of outlets are added in a microfluidic design. Polydimethylsiloxane (PDMS) microchannels were fabricated on glass slide widths of 200 μm and depths of 35 μm using soft-lithography technique [1]. The 3-outlet serpentine structure produced the best match between simulation and measurement results. The concentration profiles produce inside the channel is determined by the splitting ratio of the fluids at each branched and also depends on the number of the inlet and outlet in the tree-like network.
The gradient generator will be attached to an array of cell culture chambers with sensors that were previously developed for toxicity studies of lung cancer (A549) cell lines is shown in the Fig. 2. Cells cultured in the sensor will begin to attach and spread on the surface of the electrodes, restricting current flows from the electrodes to the surrounding media. In a confluent (all surface covered with cells) cell layer, current must travel through the intercellular space of the cell-cell and also the tight gap of the cell-electrode pairs to reach surrounding media. The more adhered the cells are with each other and with the elec
Piezoelectric sensors with the receptor coating on the basis of molecularly imprinted polymers of cefotaxime and penicillin G obtained by the electropolymerization method directly on the surface of the sensor's electrode have been developed. The obtained calibration curves are linear in the range of concentrations (ng·mL-1) 5 – 150 and 10 – 150, the limits of detection are 3.0 and 7.6 (ng·mL-1) for penicillin G and cefotaxime respectively. The developed sensors were tested in the analysis of model solutions of antibiotics, samples of meat and milk. The analysed samples did not reveal exceeding antibiotics.
An integrated device, for real-time monitoring of glucose and phenols absorption, that consists of a sensors/biosensors system (SB) and a Caco-2TC7 human intestinal cell culture, is shown here. The SB was made of a glucose oxidase-based biosensor, a sentinel platinum sensor, a laccase/tyrosinase-based biosensor and a sentinel carbon sensor located in the basolateral compartment (BC) of a cell culture plate. This system was able to monitor the glucose absorption and the hypoglycemic effect induced by different polyphenols and could be proposed to provide an effective strategy to manage postprandial hyperglycemia with natural compounds.
In this paper, a home-made SPR analytical system and a denaturalized bovine serum albumin (dBSA) SPR chip were used to detect biotin based on the method of an inhibition immunoassay. The experimental was compared with a commercial protocol. The conditions of regeneration were optimized. The dBSA SPR chip was fabricated by a self-assembling method and the derivative of biotin was immobilized on the dBSA SPR chip by using a on-line mode. A commercial instrument and a dextran-SPR-chip (CM5) were used to implement the same experiments.
Based on the experiments of immune reactions between biotin antibody and biotin derivative, the biotin antibody concentration was optimized at about 5 μg/mL in order to obtain highly sensitivity, which was used in the followed inhibition immunoassays. The lowest detection limit for biotin is 0.1 μg/mL with a detection range of 0.1-1000 μg/ml by using our home-made instrument and the dBSA-SPR-chip. The detection results of our instrument and dBSA SPR chip are comparable with the commercial protocol. Our home-made instrument and dBSA-SPR-chips can be also applied to detect other small molecules based on the indirect inhibition immunoassay.
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