4.2.5 A MEMS Based FabryPerot Protein Sensor with Reference Sensor

Event
14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany
Chapter
4.2 Biosensors IV (Systems)
Author(s)
H. Oyama, K. Takahashi, N. Misawa, K. Okumura, M. Ishida, K. Sawada - Toyohashi University of Technology (Japan)
Pages
352 - 355
DOI
10.5162/IMCS2012/4.2.5
ISBN
978-3-9813484-2-2
Price
free

Abstract

We have developed a label-free protein sensor based on a MEMS Fabry-Perot interferometer assembled with a reference protein sensor, which simultaneously measures a surface stress and transmittance change caused by immobilization of proteins. The MEMS protein sensor is composed by a silicon photodiode and a free-standing thin film with a nano cavity. A deflection of the thin film caused by an antigen-antibody reaction is detected by a photocurrent change. The MEMS protein sensor utilizes nonlinear transmittance change by using the Fabry-Perot interference to enhance the sensitivity of surface stress. Theoretical minimum detectable surface stress of the proposed sensor is predicted -1µN/m which is two orders of magnitude smaller than piezoresistive type. On the other hand, a reference sensor without the nano cavity measures a transmittance change caused by proteins and liquids. We fabricated the MEMS sensor and the reference sensor in a same chip by semiconductor planer process. A photocurrent from the MEMS protein sensor was demonstrated to shift by 23.7 nA at 3 V bias voltage with immobilized antibodies without any transmittance change on the reference sensor.

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