Ultra-sensitive photonic integrated circuit-based biosensors for healthcare applications

Evanescent field based integrated optics have great potential as a chip-based platform for label-free detection of molecular interactions. Implementation of the waveguides in an optical interferometric scheme allows for a very sensitive label-free sensor array platform as in this case small changes of the refractive index caused by the molecule capturing are easily detected. The unsurpassed sensitivity of especially the aMZI (asymmetric-Mach-Zehnder interferometer) sensor, in combination with the extreme uniformity of these sensing arrays allows for screening of proteins as well as small molecule drug candidates. However, to become interesting for the market, much more has to be in place: optimized surface functionalization chemistry, combination with microfluidics, and preferably hybrid integration of lightsource(s) and detector(s). In this proceedings the specific aMZI sensor chip design, surface modification, readout mechanisms and first results with multiplexing two specific cancer biomarker protein (POSTN and TGFBI) will be discussed. Initial experiments show a limit of detection of 1 ng/ml (~10 pM) of POSTN in buffer solution.