Ricerc@Sapienza

We present a device based on amorphous silicon photosensors and glass-diffused waveguides to be used inside lab-on-chip systems, to perform biomolecular recognition by means of optical interaction with the analyte. A 150 × 300 μm2 p-i-n photosensor was fabricated on a 200 μm wide optical waveguide, by using standard thin film microelectronic techniques, such as: thermal diffusion processes, metals and dielectrics deposition, semiconductors growth, UV photolithography and wet-dry etching to define the structure geometries.

This paper reports on the development of a fluorescent label-free aptamer assay integrated in a lab-on-chip (LoC) system for the detection of Ochratoxin A (OTA). The detection system relies on the integration, on a single glass substrate, of an array of amorphous silicon photosensors and a long pass interferential filter. The aptamer assay, integrated into the microfluidic network, is an aptasensor having affinity versus OTA, selected as a case study. The fluorescent molecule is a "light switch" complex [Ru(phen)2(dppz)]2+.