Linear Photosensor Array for On-Chip Food Quality Control Based on Thin Layer Chromatography

In this work we report on a system for food quality analysis based on the use of a "smart" thin layer chromatography plate, which couples an amorphous silicon photosensor array to a chromatographic plate. The system is able to give quantitative information by measuring the fluorescence of the analyte during the chromatographic run. In particular, the system has been tested to detect and quantify aflatoxins B(1), B(2), G(1) and G(2). The aflatoxin quantity is proportional to the photocurrent flowing in the p-i-n amorphous silicon diode junction, as the effect of the analyte fluorescence excited by a 365 nm UV radiation. Characterization performed diluting 5-20 ng of aflatoxin in 2 mu l of methanol demonstrate the capability of the system to detect in real time the analyte separation and to quantify the toxin.