Multiple Wavelength Integrated Young Interferometer for Ultra-Sensitive Sensing

 

With the integrated optical Young interferometer sensor, which was developed before in the NBP group (see figure 1), we can very sensitively detect refractive index changes. In this way it is possible to detect an analyte concentration in a given sample solution, such as virus particles and proteins. Although this method is very sensitive, certain applications of this sensor are constrained by limited specificity. Refractive index changes due to non-specific binding or due to bulk changes cannot be discriminated from the refractive index changes due to the process where you are interested in. To overcome this problem, the idea is to use an alternative method with multiple wavelengths (see figure 2). This Lab-on-a-Chip diagnostic device, based on the multiple wavelength excitation, will be developed to study of nanoscale protein aggregates related to Parkinson’s and Alzheimer’s disease. Selective detection of protein aggregation on the sensor surface without interference from the proteins in the solvent will become feasible with this new sensor.

Fig.1: Integrated Young interferometer immunosensor [1].

Fig.2: Waveguide structure with mode profiles of three different wavelengths to discriminate between specific binding, non-specific binding and refractive index change in solvent which is covering the waveguide.

1. Ymeti, A., et al., Fast, ultrasensitive virus detection using a young interferometer sensor. Nano Letters, 2007. 7(2): p. 394-397.

PhD Student: Harmen Mulder
Project leader: Hans Kanger