Application of a new microcantilever biosensor resonating at the air–liquid interface for direct insulin detection and continuous monitoring of enzymatic reactions
Abstract
Here we describe the application of a recently developed high-resolution microcantilever biosensor resonating at the air–liquid interface for the continuous detection of antigen–antibody and enzyme–substrate interactions. The cantilever at the air–liquid interface demonstrated 50% higher quality factor and a 5.7-fold increase in signal-to-noise-ratio (SNR) compared with one immersed in the purified water. First, a label-free detection of a low molecular weight protein (insulin, 5.8 kDa) in physiological concentration was demonstrated. The liquid facing side of the cantilever was functionalized by coating its surface with insulin antibodies, while the opposite side was exposed to air. The meniscus membrane at the micro-slit around the cantilever sustained the liquid in the microchannel. After optimizing the process of surface functionalization, the resonance frequency shift was successfully measured for insulin solutions of 0.4, 2.0, and 6.3 ng ml^(−1). To demonstrate additional application of the device for monitoring enzymatic protein degradation, the liquid facing microcantilever surface was coated with human recombinant SOD1 (superoxide dismutase 1) and exposed to various concentrations of proteinase K solution, and the kinetics of the SOD1 digestion was continuously monitored. The results showed that it is a suitable tool for sensitive protein detection and analysis.
Additional Information
© 2012 Royal Society of Chemistry. Received 06 Mar 2012, Accepted 03 Jul 2012. First published on the web 06 Jul 2012. This work was supported by the research project Development of a bio/nano-hybrid platform technology towards regenerative medicine (project leader: Prof. Hidetoshi Kotera) of CREST in Japan Science and Technology Agency (JST). Jungwook Park received support from G-COE program on "Secure-life Electronics" of Ministry of Education, Culture, Sports, Science and Technology (MEXT), and Stanislav L. Karsten received support from Japan Society for the Promotion of Science (JSPS).Attached Files
Supplemental Material - c2lc40232g.pdf
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Additional details
- Eprint ID
- 35790
- Resolver ID
- CaltechAUTHORS:20121204-110240639
- Japan Science and Technology Agency (JST) Core Research for Evolutional Science and Technology (CREST)
- Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- Japan Society for the Promotion of Science (JSPS)
- Created
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2012-12-04Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field