This dissertation describes our efforts to improve sensor network performance evaluation and portability, within the context of the sensor network project Hogthrob. In Hogthrob, we faced the challenge of building a sensor network architecture for sowmonitoring. This application has hard requirements on price and performance, and shows great potential for using sensor networks. Throughout the pr...

Viruses that infect cells by uptake through endosomes have generally evolved to "sense" the local pH as part of the mechanism by which they penetrate into the cytosol. Even for the very well studied fusion proteins of enveloped viruses, identification of the specific pH sensor has been a challenge, one that has now been met successfully, for flaviviruses, by Fritz et al. (Fritz, R., K. Stiasny,...

Changes in colors of an array of optical sensors that responds in full pH range were recorded using a CCD camera. The data of the camera were transferred to the computer through a capture card. Simple software was written to read the specific color of each sensor. In order to associate sensor array responses with pH values, a number of different mathematics and chemometrics methods were investi...

In this study, we have constructed the first organic field effect sensor based on an electrolyte-insulator-semiconductor structure (OEIS) and applied this novel device to pH and DNA sensing. Variations in the insulator-electrolyte surface potential, which originate from either the change of the ionization states of the insulator surface groups or the binding of charged molecules to the insulato...

The uptake of potassium ions (K+) accompanied by an acidification of the apoplasm is a prerequisite for stomatal opening. The acidification (approximately 2-2.5 pH units) is perceived by voltage-gated inward potassium channels (K(in)) that then can open their pores with lower energy cost. The sensory units for extracellular pH in stomatal K(in) channels are proposed to be histidines exposed to ...

The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) GP64 protein mediates membrane fusion during entry. Fusion results from a low-pH-triggered conformational change in GP64 and subsequent interactions with the membrane bilayers. The low-pH sensor and trigger of the conformational change are not known, but histidine residues are implicated because the pK(a) of histidine is near the...

Acidic pH inside cells indicates cellular dysfunctions such as cancer. Therefore, the development of optical pH sensors for measuring and imaging intracellular pH is a demanding challenge. The available pH-sensitive probes are vulnerable to e.g. photobleaching or autofluorescence background in biological materials. Our approach circumvents these problems due to near infrared excitation and upco...

The JGP series Perspectives on: SGP Symposium on Mitochondrial Physiology and Medicine includes articles by Wei and Dirksen (2012) and by Santo-Domingo and Demaurex (2012), which highlight two fields of research in mitochondrial physiology experiencing renewed interest thanks to the development of new genetically encoded probes: mt-cpYFP (a mitochondria-targeted superoxide sensor) and mitoSypHe...

The DraR/DraK two-component system was found to be involved in the differential regulation of antibiotic biosynthesis in a medium-dependent manner; however, its function and signaling and sensing mechanisms remain unclear. Here, we describe the solution structure of the extracellular sensor domain of DraK and suggest a mechanism for the pH-dependent conformational change of the protein. The str...

The explosive growth in the healthcare and lifestyle application has fueled recent research efforts to increase both integration and adaptability in biosensor readout design. Potentiometric sensor is emerging as important sensing devices in the areas of biomedical applications since the pioneer work on pH sensor has been introduced (Bergveld, 1970). It has appreciable advantages over traditiona...