Real-time PCR melting analysis with fiber optic SPR enables multiplex DNA identification of bacteria.

A fiber optic surface plasmon resonance (FO-SPR) technology was developed that enables simultaneous quantification and identification of multiple DNA targets on the same platform. The bioassay was based on the hybridization/melting of DNA-coated Au nanoparticles on the FO-SPR sensor when targets are present. The multiplex concept was successfully demonstrated on two related bacteria and for detection of multiple mutations in sequences. In conclusion, FO-SPR technology shows a great potential as a next generation in vitro diagnostics tool.

Enabling fiber optic serotyping of pathogenic bacteria through improved anti-fouling functional surfaces.

Significant research efforts are continually being directed towards the development of sensitive and accurate surface plasmon resonance biosensors for sequence specific DNA detection. These sensors hold great potential for applications in healthcare and diagnostics. However, the performance of these sensors in practical usage scenarios is often limited due to interference from the sample matrix. This work shows how the co-immobilization of glycol(PEG) diluents or 'back filling' of the DNA sensing layer can successfully address these problems. A novel SPR based melting assay is used for the analysis of a synthetic oligomer target as well as PCR amplified genomic DNA extracted from Legionella pneumophila. The benefits of sensing layer back filling on the assay performance are first demonstrated through melting analysis of the oligomer target and it is shown how back filling enables accurate discrimination of Legionella pneumophila serogroups directly from the PCR reaction product with complete suppression of sensor fouling.