Enhanced fluorescence detection of miRNA-16 on a photonic crystal.

We report a novel sensing method for fluorescence-labelled microRNAs (miRNAs) spotted on an all-dielectric photonic structure. Such a photonic structure provides an enhanced excitation and a directional beaming of the emitted fluorescence, resulting in a significant improvement of the overall signal collected. As a result, the Limit of Detection (LoD) is demonstrated to decrease by a factor of about 50. A compact read-out system allows a wide-field imaging-based detection, with little or no optical alignment issues, which makes this approach particularly interesting for further development for example in microarray-type bioassays.