Portable Surface Plasmon Resonance Biosensor for Detection of Nucleic Acids

We present a portable surface plasmon resonance (SPR) sensor based on spectroscopy of surface plasmons on a special diffractive structure. The sensor combines a microfluidic cartridge incorporating the special diffractive structure functionalized with DNA probes and a compact SPR reader. We apply the sensor to detection of nucleic acids employing two most common immobilization methods: (a) biotinylated probes immobilized using the biotin-streptavidin chemistry and (b) thiolated probes attached directly to the surface of the SPR sensor. It is demonstrated that both these immobilization methods allow detecting short nucleic acids at levels below 100 pM.