You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither SPIE nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the SPIE website.
4 August 2009Selective functionalization of gold arms of a surface plasmon polariton Mach-Zehnder interferometer for biosensing
In long range surface plasmon polariton (LRSPP) sensing, in a Mach-Zehnder interferometer (MZI) configuration, gold arms have to respond differently to the analyte as to form layers with different refractive indices. This can be achieved if the arms are coated with different thiol-based self-assembled monolayers (SAMs), one of which should block adsorption and the other should specifically adsorb the analyte of interest. Since the MZI arms' width and the distance between them are in the micron range, such a chemical differentiation is a challenging task which nevertheless could be achieved with two techniques (1) Microspotting trough droplet confinement and manipulation using a solvophilic guide and (2) Toposelective electrochemical desorption of SAMs where the arms are subjected to different potentials. We found the latter approach the most promising because of its scalability to the wafer level. During the electrochemical desorption the potentials of both arms have to be independently controlled with a multi-channel potentiostat. Subsequent deposition of another SAM on the freed MZI arm is accomplished with minimal thiol exchange. The resulting MZI was analyzed and imaged by time-of-flight secondary ion mass spectrometry (ToF- SIMS) and with phase shift atomic force microscopy which confirms the desired MZI structure in which only one arm has specific affinity to one protein while the other would block any interaction.
The alert did not successfully save. Please try again later.
Michal Tencer, Pierre Berini, "Selective functionalization of gold arms of a surface plasmon polariton Mach-Zehnder interferometer for biosensing," Proc. SPIE 7386, Photonics North 2009, 73862U (4 August 2009);