tailieunhanh - OPTICAL BIOSENSORS PRESENT AND FUTURE - PART 2 (end)

Tham khảo sách 'optical biosensors present and future - part 2 (end)', giáo dục - đào tạo, cao đẳng - đại học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Optical Biosensors Present and Future . Ligler and . Rowe Taitt editors 2002 Elsevier Science . All rights reserved Chapter 10 Genetic Engineering of Signaling Molecules Agatha Feltus . and Sylvia Daunert . . Departments of Chemistry and Pharmaceutical Sciences University of Kentucky Lexington KY USA In order to expand the capabilities of biosensors there is a need to develop new signaling molecules. This chapter focuses on molecules produced through genetic engineering that combine the recognition element with a signaling element such as a fluorophore in an effort to optimize the signal caused by the binding of the analyte to the recognition element. These systems while not necessarily originally developed for an optical fiber can be immobilized at the tip of the fiber either through chemical attachment or entrapment behind a membrane. Three different systems will be examined fluorophore-labeled binding proteins FRET-based systems and bacteria-based sensors. These systems use optical signaling methods to reveal the binding event taking advantage of molecular biological techniques to optimize the signal. The advantages and disadvantages of each system will be discussed as well as the current state of the art of these biosensors. 1. Technical Concept In its simplest terms a biosensor is a sensing system composed of a biological recognition element and a transducer. Under the strictest definition of the term the transducer is responsible for converting the binding event into an electrical signal. Bacteria that fluoresce upon analyte binding and fluorophore-labeled binding proteins have been refered to as reagentless biosensors or reagentless biosensing systems even though they are used as assays rather than 307 Feltus and Daunert immobilized in a sensor. There is no reason these sensing systems cannot be used as the recognition signaling element of a fiber optic biosensor however. These systems will be discussed in both contexts . both free