In this issue

Abstract

AbstractProcess analytical sensors for single‐use bioreactorsBluma et al., Eng. Life Sci. 2011, 11, 550–553.Online measurement of process parameters within bioreactors is still a challenge. Most analytical sensor systems used in the conventional stirred‐tank reactors cannot be transferred to single‐use bioreactors. This is because most conventional sensor systems are invasive and must be sterilized, calibrated, and validated before use. In addition, regulations of the US Food and Drug Administration concerning process documentation, imposed by the Process and Analytical Technology (PAT) Initiative, have increased the demand for sensors that are able to very accurately monitor and document the production process. In this issue, Sascha Beutel et al. (Hanover, Germany) compare sensor systems that are currently on the market for single‐use bioreactors and discuss the use of image‐based biosensors.……………550.http://dx.doi.org/10.1002/elsc.201000191magnified imageProtein‐based optical device with reset functionFrasca et al., Eng. Life Sci. 2011, 11, 554–558.Analytical single‐use test strips evaluated by a color change have been used in industry/academia for almost half a century. In this issue, Ulla Wollenberger and co‐workers (Golm and Gießen, Germany) present the development of a reusable sensing system coupled to optical detection. In their model, cytochrome c was immobilized in a mesoporous indium tin oxide film. The cytochrome c‐catalyzed oxidation of a redox‐sensitive dye is then measured spectroscopically. When the dye is co‐immobilized with the protein, its redox state can be easily controlled by application of an electrical potential at the supporting material. This electrochemical reset function enables repetitive signal generation and direct calibration of small test devices. The described principle can be extended to other color‐forming redox reactions and enzyme systems.……………554http://dx.doi.org/10.1002/elsc.201100079magnified imageAptasensor platform based on surface plasmon resonanceHenseleit et al., Eng. Life Sci. 2011, 11, 573–579.Aptamers are synthetic single‐stranded oligonucleotides exhibiting several advantages for their use as biosensors compared with antibodies: target molecules include toxic or pathological substances, production is quicker and cheaper, they are easy to modify without loss of activity and show high stability under a width range of conditions. In this issue, researchers from the Technical University and Fraunhofer Institutes in Dresden, Germany present a novel aptasensor platform based on a surface plasmon resonance (SPR)‐system using a thrombin–aptamer interaction as a model system. The platform is intended to be used as a low‐cost biosensor, which is robust, easy to transport, and demonstrates sensitive and label‐free detection of target molecules, such as peptides, proteins, nucleotides, and whole virus particles.……………573http://dx.doi.org/10.1002/elsc.201100036magnified image