SPR bacterial pathogen biosensor: the importance of fluidic conditions and probing depth.
The sensitivity of surface plasmon resonance (SPR) biosensor technology for detection of bacterial analytes is investigated as a function of (a) sample flow conditions and (b) depth of probing electromagnetic field. These parameters are extremely important as such analytes exhibit large (of around micrometer) size which significantly hinders their diffusion-driven transfer from a liquid sample to the sensor and their subsequent specific capture by attached recognition elements. This is due to small diffusion coefficient and strong shear stress that decreases the stability of bonds between the bacterium specific epitope and recognition elements immobilized at the sensor surface. The importance of accurate control of sample flow conditions and probing depth in order to maximize SPR sensor response is experimentally demonstrated and supported by an analytical theory. The tuning of the probing depth of surface plasmon evanescent field to match the size of the target analyte is pursued by using long range surface plasmons.
Graduate Institute of BioMedical Engineering, National Central University, (32001) No. 300, Jhongda Rd., Jhongli City, Taoyuan County 320, Taiwan.
Chun Jen
CJ
Huang
AIT - Austrian Institute of Technology, BioSensor Technologies, Muthgasse 11, 1190 Vienna, Austria.
Wolfgang
W
Knoll
AIT Austrian Institute of Technology, Bioresources Unit, Konrad-Lorenz-straße 24, 3430 Tulln, Austria.
Angela
A
Sessitsch
AIT - Austrian Institute of Technology, BioSensor Technologies, Muthgasse 11, 1190 Vienna, Austria. Electronic address: jakub.dostalek@ait.ac.at.
Jakub
J
Dostalek
D015374:Biosensing Techniques / Q000379:methods; D055590:Electromagnetic Phenomena; D048168:Escherichia coli K12 / Q000737:chemistry* / Q000378:metabolism; D020349:Surface Plasmon Resonance / Q000379:methods
Bacterial pathogen; Biosensor; Diffusion limited mass transfer; Long range surface plasmon; Shear stress; Surface plasmon resonance