Lab on Chip: Portable Optical Device for On-site Multi-parametric Analysis

Recently the demand dramatically grew up for portable biosensors, providing an on-site multi-parametric measurement. Present instruments, however, are limited by large size and consumption (which prevents portability) and costs (which prevents their usage in some Countries). In this paper, we propose a compact and portable device based on a nano-structured array biochip featuring the Surface Plasmonic Resonance, lighted by a suitable optics and equipped with an 830 nm irradiating LED. The reflected image is detected by an Aptina CMOS sensor and managed by an ARM9 processor which is responsible of the acquisition end processing, performed within 14 sec form the application of the assy. The processor evaluates the average grey level pixel ratio between suitable biochip areas so as to be independent on illumination fluctuations and external noise. Preliminary results indicate a sensitivity close to 10-4 RIU change in the refractive index and applicability of the device to different applications and fields (waste water and food pollution analysis, among the main ones).