Evanescent resonator chips: a universal platform with superior sensitivity for fluorescence-based microarrays

Abstract

In the present paper, we introduce for the first time a novel generation of a universal fluorescence transducer, the so-called evanescent resonator (ER) platform. The device comprises a transparent substrate and a thin dielectric surface layer containing sub-micron corrugated structures. The ER chip exhibits an inherent physical signal amplification due to confinement of excitation energy in the thin surface layer. Energy confinement is based on interference effects created by the abnormal reflection geometry and leads to efficient excitation of surface-bound fluorophores in the evanescent field of the chip. The evanescent resonator platform has the potential to increase the fluorescence yield of labelled biomolecules to more than 100-fold when compared with conventional microarray chips. The new ER device has been developed for analysis of nucleic acids from different species. However, it can be used with all kinds of biomolecular affinity systems. The platform combines superior sensitivity with exceptional reproducibility and ease of use. The chips are compatible with commercially available laser scanners, confocal microscopes, and portable or miniaturised CCD read-out equipment.