[12a-PB3-1~16] 13.4 Si processing /Si based thin film / MEMS / Equipment technology

△ [12a-PB3-13] Displacement detection lower limit evaluation and label-free molecular detection of optical interferometric surface stress sensor

〇Satoshi Maruyama¹, Yong Joon Choi¹, Kazuhiro Takahashi^1,2, Kazuaki Sawada¹ (1.Toyohashi Tech., 2.JST PRESTO)

Keywords:Fabri-Perot interferometric sensor, MEMS, antigen-antibody reaction

We report an improved minimum detectable displacement on a surface stress biosensor using optical interferometry, allowing for the detection of a low concentration of biomarker via antigen-antibody reaction. The sensor is composed of a sub-micron thickness freestanding poly methyl methacrylate/parylene-C membrane on a polydimethylsiloxane (PDMS) substrate with a micro cavity to generate optical interference. The cavity structure was fabricated by transferring the sub-micron thick bilayer to the highly adhesive PDMS. The detection of human serum albumin antigen at a concentration of 1 pg/mL was achieved by antigen-antibody reaction using simultaneous optical and electrical measurements. In addition, the minimum detectable displacement of the optical interferometric surface stress sensor was determined to be 116 pm, representing a 4.3-fold improvement compared to conventional cantilever-based surface stress sensors.