PLATON SiNsor - Silicon nanophotonic biosensor

Partners:
ams AG (Coordinator)
Innsbruck Medical University (MUI)

 

The development of label-free biosensors is of significant interest for real-time detection of biomolecular interactions for clinical applications, which affects all aspects of medicine. It is expected, that according sensors will gain importance in medical diagnostics in the coming years. In this context, silicon photonic evanescent wave biosensors have increasingly attracted attention. Most prominent demonstrations in this field were realized employing the monocrystalline silicon device layer on a several micrometer thick layer of silicon oxide (so-called silicon-on-insulator (SOI) wafers). However, SOI represents a rather cost intensive platform, which conflicts with the requirement that optical biosensors should be cheap single-use devices suitable for mass production.

Therefore, for commercialization a sensor concept compatible with a cost-effective fabrication technology platform, which is better scalable than SOI in terms of mass production, is indispensable. Silicon nitride layers fabricated by CMOS-compatible standard semiconductor foundry processes can be used as waveguides. Moreover, silicon nitride is transparent also below 1.1 µm wavelength, offering the additional beneficial option of monolithic co-integration of these optical waveguides with silicon photodiodes and read-out circuitry. Such a combination opens up many possibilities for novel photonic integrated circuit devices in various fields of application such as sensing or data communication.

In SiNsor, the goal was to develop a waveguide based biosensing platform. Together with ams AG a CMOS-compatible low-loss silicon nitride waveguide technology platform was established. After optimization of the fabrication processes the optical waveguides showed propagation losses below 1dB/cm at a wavelength of 850 nm. In addition, AMS demonstrated that this waveguide fabrication process is in principle fully compatible with the optoelectronic production processes.

The silicon nitride waveguide technology platform was used by AIT for the realization of Mach-Zehnder interferometer based multi-channel biosensors allowing label-free molecular detection. In-depth biosensing experiments on the kinetics of the S-peptide/S-protein interaction were carried out with concentration levels down to 3 ng/ml. Moreover, preliminary biosensing measurements were performed using a four channel MZI sensor array.

 

 

This work was supported by the Austrian NANO Initiative of the Austrian Research Promotion Agency (FFG) under the PLATON SiNsor grants (project no. 834931).

References:

E. Melnik, · P. Muellner, · G. C. Mutinati, · G. Koppitsch, · F. Schrank, · R. Hainberger, · M. Laemmerhofer, "Local functionalization of CMOS-compatible Si3N4 Mach-Zehnder interferometers with printable functional polymers", Sensors and Actuators B Chemical, in press (2016) (doi:10.1016/j.snb.2016.05.121)

P. Muellner, E. Melnik, G. Koppitsch, J. Kraft, F. Schrank, R. Hainberger, "CMOS-compatible Si3N4 Waveguides for Optical Biosensing", Procedia Engineering 120, pp. 578–581 (2015) (doi:10.1016/j.proeng.2015.08.728)

E. Melnik, P. Muellner, O. Bethge, E. Bertagnolli, R. Hainberger, M. Lämmerhofer, "Streptavidin binding as a model to characterize thiol-ene chemistry-based polyamine surfaces for reversible photonic protein biosensing", Chem. Commun. 50(19), pp. 2424-2427 (2014) (doi:10.1039/C3CC48640K)