BACKGROUND Continuous amperometric sensors that measure glucose or lactate require a stable sensitivity, and glutaraldehyde crosslinking has been used widely to avoid enzyme loss. Nonetheless, little data is published on the effectiveness of enzyme immobilization with glutaraldehyde. METHODS A combination of electrochemical testing and spectrophotometric assays was used to study the relations...

A key challenge for sensor miniaturization is to create electrodes with smaller footprints, while maintaining or increasing sensitivity. In this work, the electroactive surface of gold was enhanced 30-fold by wrinkling followed chronoamperometric (CA) pulsing. Electron microscopy showed increased roughness in response an number CA pulses. The nanoroughened also excellent fouling resistance when...

an extended octagonal ring (eor) transducer was designed and developed to measure forces inside the compression chamber of a large square baler in different directions. the transducer was calibrated by applying forces in three directions simultaneously and independently. the sensor revealed excellent linearity along with small cross sensitivities. horizontal and vertical primary sensitivities o...

soil compaction and moisture content are two of the factors that greatly influence variations in crop yield. capacitance-based sensor is a sensitive device for estimating soil water content. in this method of soil moisture content measurement, soil acts as the dielectric of the capacitor. throughout this research work, a capacitance-based moisture sensor that can measure the soil moisture conte...

wireless sensor networks are composed of hundreds or thousands of small nodes called sensor that work together and are associated with a specific task or tasks to do. each of these nodes includes sensor, processor, communication components, a small memory and a source of energy. it is expected that wireless sensor networks will be used widely in many applications in near future. scalability and...

Since a bird’s metabolic rates are finely tuned to their environments, research on avian systems plays an important role in investigation of ecology. Here, for the first time, we have developed a miniature needle-type enzyme sensor system suitable for continuous real-time amperometric in-vivo monitoring of uric acid levels in birds. In addition to extensive characterization of the sensor system...

A diffusion-kinetic model is presented for an enzyme-modified microcylinder electrode, where the enzyme reaction generates an electro-active product. Simple, approximate expressions are derived for the steady-state current in cases where the enzyme is immobilized in a metallically conducting, or a non-conducting matrix. The model is also extended to the chemical sensor case, of a conducting pol...

coverage improvement is one of the main problems in wireless sensor networks. given a finite number of sensors, improvement of the sensor deployment will provide sufficient sensor coverage and save cost of sensors for locating in grid points. for achieving good coverage, the sensors should be placed in adequate places. this paper uses the genetic and learning automata as intelligent methods for...

Adequate coverage is one of the main problems for distributed wireless sensor networks and The effectiveness of that highly depends on the sensor deployment scheme. Given a finite number of sensors, optimizing the sensor deployment will provide sufficient sensor coverage and save power of sensors for movement to target location to adequate coverage. In this paper, we apply fuzzy logic system to...