Nevertheless, two major improvements are introduced in the present work: (a) the on-chip microfluidic chamber is miniaturized so as to reduce the sample volume from 100 to 20 μl, without reducing the surface area available for biofunctionalization, and (b) the optical set-up was combined with a computer controlled stage which allowed scanning across the long axis of the sensing surface providing for real-time multi-analyte determinations in the same sample. The developed dual-analyte sensing system was evaluated in terms of its analytical characteristics and compared to standard diagnostic laboratory instrumentation using human blood plasma samples.