Impact of ParticulateAntigens, Such as Bacillus anthracis, on the Uniformityof Response across a Biosensor Flow Cell As Determined by GC-SPR.

Biosensors are desired for the detection of a wide rangeof analytes in various scenarios, for example environmental monitoringfor biological threats, from toxins to viruses and bacteria. Ideallya single sensor will be capable of simultaneous multianalyte detection.The varying nature, and in particular disparate size, of such a varietyof analytes poses a significant challenge in the development of effectivehigh-confidence instruments. Many existing biosensors employ functionalizedflow cells in which spatially defined arrays of surface-immobilizedrecognition elements, such as antibodies, specifically capture theiranalyte of interest. To function optimally, arrays should provideequivalent responses for equivalent events across their active area.Experimental data obtained using a grating coupled surface plasmonresonance (GC-SPR) instrument, the BIAcore Flexchip, have revealeddifferences in response behaviors between proteinaceous and particulateanalytes. In particular, the magnitude of responses seen with Bacillus anthracisspores appears to be influenced by shearand gravitational effects while those from soluble proteins are moreuniform. We have explored this dependence to understand its fundamentalimpact on the successful implementation of multianalyte environmentalbiological detection systems. [ABSTRACT FROM AUTHOR]