Affinity biosensors

A biosensor is a device that combines a biological component a recognition layer) and a physico-chemical detector component (a transducer). The transduction unit can be electrochemical, optical, piezoelectric, magnetic, or calorimetric (1). Two groups of recognition molecules form the majority of biosensors affinity-based and catalytic-based biosensors. Affinity-based biosensors are used to bind molecular species of interest, irreversibly and noncatalytically. Examples include antibodies, nucleic acids, and... 

Results on DNA-based biosensors will be presented they have been used mainly for two kind of applications 1) for the determination of low-molecular weight compounds witlr affinity for nucleic acids and 2) for the detection of hybridization reaction. 

One way to reduce the number of independent variables in the FRET-adjusted spectral equation is to use samples with a fixed donor-to-acceptor ratio. Under these conditions, the values of d and a are no longer independent, but rather the concentration of d is now a function of a and vice-versa. This approach is typical for the situation of FRET-based biosensor constructs. These sensors normally are designed to have a donor fluorophore attached to an acceptor by a domain whose structure is altered either as a result of a biological activity (such as proteolysis or phosphorylation), or by its interaction with a specific ligand with which it has high affinity. In general, FRET based biosensors have a stoichiometry of one... 

Affinity Biosensors Based on Spectroscopy of Guided Waves... 

Main types of biomolecular recognition elements used in affinity biosensors based on spectroscopy of guided modes include antibodies, nucleic acids and biomimetic materials. Antibodies are used most frequently because of their high affinity, versatility, and commercial availability. 

Figure 8. Concept of affinity biosensor based on spectroscopy of guided waves.

Affinity biosensors based on spectroscopy of guided modes have been used for detection of small analytes such as pesticides and herbicides... 

Representatives of medium-size analytes detected by affinity biosensors based on spectroscopy of guided modes include food-safety related analytes such as staphylococcal enterotoxin B , botulinum toxin, and E. coli... 

Large analytes targeted by affinity biosensor technology include bacterial pathogens such as Escherichia coli, Salmonella enteritidis, and Listeria monocytogenes. Salmonella enteritidis and Listeria monocytogenes were detected by an SPR sensor at concentrations down to 106 cfu/ml27. 

Future development of affinity biosensors based on spectroscopy of guided waves will be driven by the needs of the consumer. These biosensor technologies hold potential to benefit important fields including pharmaceutical research, medical diagnostics, environmental monitoring, food safety, and security. Applications in these areas will challenge research and development in the field. 

B. Bucur, A.F. Danet, and J.L. Marty Versatile method of cholinesterase immobilisation via affinity bonds using concanavalin A applied to the construction of a screen-printed biosensor. Biosens. Bioelectron. 20, 217-225 (2004). 

F. Frederix, K. Bonroy, W. Laureyn, G. Reekmans, A. Campitelli, W. Dehaen, and G. Maes, Enhanced performance of an affinity biosensor interface based on mixed self-assembled monolayers of thiols on gold. Langmuir 19, 4351-4357 (2003). 

Bioresorbable polymers, 3 735-740 Bioselective adsorption, 6 387 Biosensors, 3 794-815 14 154 22 269 affinity DNA biosensors, 3 805-808 affinity immunosensors, 3 800-805 applications, 3 812-813 biomimetic sensors, 3 809-810 catalytic, 3 796-799 cellulose ester applications, 5 408 comparison with microarrays, J6 38It evolution of, 16 380-381 production by thick-film technology, 3 810-812... 

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