Abstract
The use of microfabricated cantilevers as immunosensors for the detection of human interleukin-1 beta (HIL1-β), one of the proinflammatory cytokines, is demonstrated. Cytokines are important biomarkers to monitor the effect of drugs influencing the immune system or inflammation. Nanostructured microcantilevers (MCs) functionalized with anti-human interleukin-1 beta (anti HIL1-β) antibody (Ab) are used for achieving immunonanomechanical responses. Antibody-antigen binding interaction induces an apparent surface stress, thereby causing static bending of the MC that is detected in this work by an optical beam bending technique. Specific binding of HIL1-β to surface-bound Ab produces substantial compressive surface stress, which enables its detection in presence of other interfering proteins. Combination of biospecificity of antibodies with the sensitivity of nanomechanical surface stress detection using MCs with one side nanostructured allows detection of cytokine HIL1-β in the ppb range. The nanostructured immuno-MCs, when compared to the smooth surface MC, exhibit higher responses and yet better reversibility. The detection of HIL1-β shows good measurement reproducibility (CV = 10%) in the same day tested via three replicate consecutive measurements of a solution of 0.5 ppm of HIL1-β. Also, a reasonable stability of the Ab functionalized MC within 7 d of functionalization is observed. It can be envisioned that differentially functionalized MC arrays can be made in a similar fashion.
Original language | English |
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Pages (from-to) | 237-244 |
Number of pages | 8 |
Journal | Nanobiotechnology |
Volume | 1 |
Issue number | 3 |
DOIs | |
State | Published - 2005 |
Externally published | Yes |
Funding
This research was supported by the U.S. Department of Energy, Environmental Management Science Program under Grant DOE FG07-01ER62718 and Office of Basic Energy Sciences under Grant DOE FG02-02ER15331. HIL1-β and anti-HIL1-β were purchased by J. Sanseverino.
Keywords
- Cytokine detection
- Immunosensor
- Microcantilevers
- Nanostructured