Single beam grating coupled interferometry: high resolution miniaturized label-free sensor for plate based parallel screening

Grating Coupled Interferometry (GCI) using high quality waveguides with two incoupling and one outcoupling grating areas is introduced to increase and precisely control the sensing length of the device; and to make the sensor design suitable for plate-based multiplexing. In contrast to other interferometric arrangements, the sensor chips are interrogated with a single expanded laser beam illuminating both incoupling gratings simultaneously. In order to obtain the interference signal, only half of the beam is phase modulated using a laterally divided two-cell liquid crystal modulator. The developed highly symmetrical arrangement of the interferometric arms increases the stability and at the same time offers straightforward integration of parallel sensing channels. The device characteristics are demonstrated for both TE and TM polarized modes. (C)2012 Optical Society of Americ

Development of a high sensitivity label free waveguide interferometry instrument : a project of Creoptix GmbH with the center for Biochemistry ZHAW as main research partner

Creoptix GmbH has developed a novel and innovative technology for label-free detection of molecules based on grating-coupled interferometry (GCI). GCI is a proprietary technology characterized by a very high sensitivity at low technical complexity. One main application will be the measurement of binding affinities in research and development projects such as drug discovery. Goal of an interdisciplinary CTI project with the partners from ZHAW, FHNW and CSEM together with Creoptix is the development of a first GCI instrument including disposables and the optimization of its functionality, followed by field tests to pave the way to market introduction

Grating coupled optical waveguide interferometer for label-free biosensing

A phase shifting optical waveguide interferometer is demonstrated for label-free evanescent wave biosensing in aqueous solutions. In the proposed configuration, the reference and measurement arms of the interferometer are combined inside an integrated optical Ta(2)O(5) waveguide using an ion implanted grating. Biomolecules adsorbing on the waveguide surface shift the phase in the measurement arm, which is modulated at the same time by a periodically relaxing liquid crystal phase modulator. It is demonstrated that by analyzing the periodic intensity response at the end facet of the waveguide, the phase shifts in the measurement arm can be monitored in real-time with a precision of 10(-4) rad. The high phase resolution allows the detection of surface adsorbed molecule densities below 1 pg/mm(2) without using any labeling or on-chip referencing. The instrument performance is demonstrated by monitoring in situ protein adsorption and affinity binding of low molecular weight pure biotin to an immobilized avidin layer. (C) 2011 Elsevier B.V. All rights reserved

Multidepth screening of living cells using optical waveguides

The use of planar optical waveguides as substrata for label-free, non-invasive monitoring of cells growing on them is demonstrated. Different submicrometre depths (measured from and perpendicular to the substratum surface) can be selected for monitoring. The so-called symmetry waveguide configuration with a low refractive index waveguide support (nanoporous silica with refractive index similar to 1.2) and a polystyrene waveguiding film with a heat-embossed grating coupler is exploited to obtain practically useful differences between the penetration depths of different waveguide modes. Robust data processing techniques are developed to obtain quantitative information about the cell refractive index profile perpendicular to the substratum from the measured effective refractive indices of the modes. In particular, a method is introduced with which cell refractive index variations above and below a predefined and tunable depth can be separated using two modes. The technique can be extended to more modes to gain even more comprehensive information from predefined submicrometre slices of the cell layer. The introduced methods are also suitable for monitoring the kinetics of changes in cell refractive index profiles. (C) 2008 Elsevier B.V. All rights reserved

Development of a high sensitivity label-free waveguide interferometry instrument : a project between the Center for Biochemistry at the Institute of Chemistry and Biological Chemistry ZHAW as main research partner and Creoptix GmbH

SCS-FH Awards at the ILMAC 2013Creoptix GmbH has developed a novel and innovative technology for label-free detection of molecules based on grating-coupled interferometry (GCI). GCI is a proprietary technology characterized by a very high sensitivity at low technical complexity. One main application will be the measurement of binding affinities in research and development projects such as drug discovery. Goal of an interdisciplinary CTI project with the partners from ZHAW, FHNW and CSEM together with Creoptix is the development of a first GCI instrument including disposables and the optimization of its functionality, followed by field tests to pave the way to market introduction