However, the performance of these SPR sensors in practical usage scenarios is often limited because of interference from the sample matrix as non-specific sorption of proteins can easily lead to false positive signals. In trying to solve these issues, researchers from the MeBioS Biosensor group at KU Leuven, Belgium, led by Prof. Jeroen Lammertyn, found that co-immobilization of specific glycol (PEG) diluents or “back filling” of the DNA sensing layer can successfully address these problems. This has enabled the team to develop a novel SPR-based melting assay that can be used to serotype pathogenic bacteria based on their genomic DNA.

The scientists demonstrated the effectiveness of their strategy through the accurate discrimination of Legionella pneumophila serogroups directly from PCR reaction products with the complete suppression of sensor fouling and without the need for any sample preparation.

The anti-fouling SPR sensor developed by the MeBioS biosensor group was recently shown to be compatible with specific DNA detection during PCR cycling. An additional advantage of the presented SPR system is the ability to perform real-time monitoring of PCR in non-transparent media that prohibit the use of more traditional fluorescence-based reporters. This has the potential to significantly reduce both the complexity and the cost of PCR-based biodetection and will be the future focus of the team.

The researchers presented their work in the journal Nanotechnology.