Biochemical processes, monitoring

Microelectronic circuits for communications. Controlled permeability films for drug delivery systems. Protein-specific sensors for the monitoring of biochemical processes. Catalysts for the production of fuels and chemicals. Optical coatings for window glass. Electrodes for batteries and fuel cells. Corrosion-resistant coatings for the protection of metals and ceramics. Surface active agents, or surfactants, for use in tertiary oil recovery and the production of polymers, paper, textiles, agricultural chemicals, and cement. 

With regard to the development of infrared sensors during the last decade, some major fields of application can be identified, covering biological, biochemical or medical applications, environmental monitoring and process monitoring, with the latter being considered as the area closest to a widespread application of IR optical sensor systems. 

Recent developments in microsystems technology have led to the widespread application of microfabrication techniques for the production of sensor platforms. These techniques have had a major impact on the development of so-called Lab-on-a-Chip devices. The major application areas for theses devices are biomedical diagnostics, industrial process monitoring, environmental monitoring, drug discovery, and defence. In the context of biomedical diagnostic applications, for example, such devices are intended to provide quantitative chemical or biochemical information on samples such as blood, sweat and saliva while using minimal sample volume. 

The properties of an ideal mass analyzer are well described, [2] but despite the tremendous improvements made, still no mass analyzer is perfect. To reach a deeper insight into the evolution of mass spectrometers the articles by Beynon, [3] Habfast and Aulinger, [4,5] Brunnee [6,7], Chapman et al. [8] and McLuckey [9] are recommended for further reading. In recent years, miniature mass analyzers have gained interest for in situ analysis, [10] e.g., in environmental [11] or biochemical applications, [12] for process monitoring, for detection of chemical warfare agents, for extraterrestrial applications, [13] and to improve Space Shuttle safety prior to launch. [14]... 

Gurden et al. studied the monitoring of batch processes using spectroscopy. As a case study, they followed a pseudo first-order biochemical reaction with an intermediate using UV-vis spectroscopy. Following statistical process monitoring, process disturbances could be detected in a series of batches. 

C. Menzel, T. Lerch, K. Schneider, R. Weidemann, C. Tollnick, G. Kretzmer, T. Scheper and K. Schuger, Application of biosensors with an electrolyte isolator semiconductor capacitor (EIS-CAP) transducer for process monitoring, Process Biochem., 33(2) (1998) 175-180. 

Examples of biochemical processes successfully studied by spectroscopic monitoring and multivariate resolution techniques include protonation and complexation of nucleic acids and other events linked to these biomolecules, such as drug intercalation processes and salt, solvent, or temperature-induced conformational transitions [90-97], In general, any change (thermodynamic or structural) that these biomolecules undergo is manifested through a distinct variation in an instrumental signal (usually spectroscopic) and can be potentially analyzed by multivariate resolution techniques. 

Another less-utilized transduction mechanism for biosensors involves the acoustoelectric effect. In principle, any biochemical process that produces a change in the electrical properties of the solution, can be monitored by observing changes in the frequency and/or attenuation of the device if its surface is not metallized. For example, a SH-SAW device has been reported for the detection of pH changes associated with the enzyme-catalyzed hydrolysis of urea [235]. Using an immobilized urease membrane on the sensor surface, it was anticipated that urea concentrations as small as 3 /u.M could be reliably detected. 

The insertion of biophysical probes into protein sequences gives an opportunity to monitor various biochemical processes, such as protein-protein interaction. In order to develop potential biosensors, disruption of the protein cooperations can be coupled to some form of signaling event, such as a fluorescence change. Ayers et al. (28) reported on the interaction between the Src homology... 

Smarter fluorescent probe devices at the nanometer scale for monitoring biochemical processes in and on cells. 

Achieving these many objectives has required not one, but several, biochemical endpoints capable of evaluating multiple biochemical processes which are essential to the health of the cell. The Tox-Cluster Assay System (89)incorporates assays that monitor mitochondrial function, mitogenesis, energy status, cell death (necrotic/apoptotic), and oxidative stress with an immortalized cell line derived from rat liver. These endpoints are monitored over exposure concentrations that range from 0.1 to 300 iiM. By combining the... 

Biosensors can be defined as chemical sensor systems in which an analyte is detected based on biochemical processes or biochemical utilization. A biosensor is mostly composed of a biological element responsible for sampling and tracing, and a physical element called a transducer responsible for sample transmission and further processing (see also Part V, Chapters 8 and 9). The term biosensor does not really meet the lUPAC definition, in which sensors are defined to be self-containing, perform continuous monitoring and are reversible. For the purpose of this chapter, the term biosensor will not be so strictly used as in the traditional context. 

The MIMS method has been used to analyze VOCs in environmental water and air samples as well as in the monitoring of chemical and biochemical processes.MIMS is faster than GC-FID and GC-ELCD. In comparison, the MIMS method in single ion mode was the more sensitive and the linear dynamic ranges were similar to those of the GC-FID method, although not all compounds could be separated because of the similarity of their mass spectra. ... 

While we accept that such an approach at the moment appears to be some solution in appeasing the appetite for data concerning organic compounds in the marine environment, it will however direct research to the monitoring of bulk biochemical processes and may reveal little more information than elemental analysis. 

Deception in crustacean chemical communication has not yet been detected. This mode of communication may most often involve the transfer of cues that are byproducts of essential biochemical processes and that cannot be faked. Yet, we see no reason, based on first principals, why deception via the withholding and directed release of such cues should be rare. But we also acknowledge that detecting such deception will be very difficult. Techniques to monitor and visualize the production and release of chemicals by senders and the detection of and responses to them by receivers under both seminatural and experimental conditions have just begun to be used to study signaling in aggressive contexts in lobsters and crayfish. 

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