Surface plasmon resonance and surface plasmon field-enhanced fluorescence spectroscopy for sensitive detection of tumor markers

• Published in: Methods in molecular biology (Clifton, N.J.) Vol. 503; p. 3
• Main Authors: Arima, Yusuke, Teramura, Yuji, Takiguchi, Hiromi, Kawano, Keiko, Kotera, Hidetoshi, Iwata, Hiroo
• Format: Journal Article
• Language: English
• Published: United States 2009
• Subjects: Biomarkers, Tumor - blood; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Blood Chemical Analysis - instrumentation; Blood Chemical Analysis - methods; Equipment Design; Equipment Failure Analysis; Humans; Immunoassay - instrumentation; Immunoassay - methods; Neoplasm Proteins - blood; Neoplasms - blood; Neoplasms - diagnosis; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Fluorescence - instrumentation; Spectrometry, Fluorescence - methods; Surface Plasmon Resonance - instrumentation; Surface Plasmon Resonance - methods
• ISSN: 1064-3745
• DOI: 10.1007/978-1-60327-567-5_1

Surface plasmon resonance (SPR), which provides real-time, in situ analysis of dynamic surface events, is a valuable tool for studying interactions between biomolecules. In the clinical diagnosis of tumor markers in human blood, SPR is applied to detect the formation of a sandwich-type immune complex composed of a primary antibody immobilized on a sensor surface, the tumor marker, and a secondary antibody. However, the SPR signal is quite low due to the minute amounts (ng-pg/mL) of most tumor markers in blood. We have shown that the SPR signal can be amplified by applying an antibody against the secondary antibody or streptavidin-conjugated nanobeads that specifically accumulate on the secondary antibody. Another method employed for highly sensitive detection is the surface plasmon field-enhanced fluorescence spectroscopy-based immunoassay, which utilizes the enhanced electric field intensity at a metal/water interface to excite a fluorophore. Fluorescence intensity attributed to binding of a fluorophore-labeled secondary antibody is increased due to the enhanced field in the SPR condition and can be monitored in real time.