Streptavidin sensing

Lee G U, Kidwell D A and Colton R J 1994 Sensing discrete streptavidin-biotin interactions with atomic force microscopy Langmuir 10 354... 

Fig. 8.20 Experimental sequence of surface sensing (a) The sensor surfaces are functionalized with biotinylated BSA (b) Streptavidin is specifically bound to the sensor surface with the biotin moiety (c) Biotin is captured on the sensor surfaces by the streptavidin...

An altemahve approach is the "mass-sensing" multianalyte microarray immunoassay first described by researchers at Beckman Coulter, Fullerton, CA (Silzel et al., 1998). As early as 1991, other groups at Beckman Coulter had adapted commercially available ink-jet printers (e.g., the Hewlett Packard Deskjet) for deposihng oligonucleohdes or proteins such as streptavidin onto substrates to create arrays (Matson, xmpublished data). Piezoelectric... 

The genosensors used for the PCR products detection are streptavidin-modified SPCEs with biotinylated probes as sensing phase [1,2]. 

Figure 6.12. Biological sensing using Ag nanoparticles. Shown is (a) a dark-field optical image of surface-functionalized (biotinylated) Ag nanoparticles, and (b) the shift in wavelength before (1) and after (2) exposure to 10 nM streptavidin. Reproduced with permission from Haes, A. J. Stuart, D. A. Nie, S. Duyne, R. R V. J. Fluoresc. 2004,14, 355. Copyright 2004 Springer Science and Business Media.

To demonstrate MT-MEC as a useful platform for protein quantification, a simple surface biotin-avidin assay was constructed[15,16]. In the assay, biotinylated-BSA is incubated on both silvered and glass substrates (Figure 15.5). HRP-streptavidin is then added to the surface, locaiizing the enzyme catalyst in close proximity to the silver for MT-MEC. The peroxide and Acridan (iumophore) are then added to initiate the chemiluminescence reaction. While this assay in essence determines BSA concentration, this model assay could indeed be fashioned to both iocaiize and sense other proteins / DNAs of interest. 

Similarly, streptavidin from Streptomyces avidinii - and also its eukaryotic counterpart avidin, which occurs in chicken egg white - has evolved only in order to tightly complex biotin, a small vitamin compound [15]. In this case the complexation is kinetically almost irreversible, which makes sense for its role as a bacterial antibiotic protein and has led to its widespread use as a biochemical reagent (for references, see [16]). 

Fig. 5 Sensorgram for streptavidin detection using the OFRR. The interior surface of the OFRR is first immobilized with probe bacteriophage R5C2, and then the unoccupied sites are blocked with BSA. Finally, the sensing surface is exposed to streptavidin. Reprinted with permission from ref. [60]...

Fig. 6 Changes in / and D measured at two harmonics ( = 3 and = 7) of a Si02-modified 5 MHz QCM crystal upon subsequent additions of biotin-containing lipid vesicles (i), streptavidin (ii), biotin-modified single stranded 15-mer DNA (iii), and fully complementary single stranded DNA (iv). Also shown at the top is a schematic representation of the sensing template, illustrating the Voigt-based representation used in the analysis of the data. Note that the DNA film was treated as one layer that undergoes a structural change dming hybridization...

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