Optimization of the protocol for the Brettanomyces bruxellensis detection using LSPR phenomenon with AuNPs.

The yeast Brettanomyces bruxellensis, is well-known in the oenological field for being the cause of significant defects in wine called “Brett character”. B. bruxellensis is responsible for contamination of cellars that lead to consequent economic losses. Classical plate methods and molecular techniques such as PCR, nested-PCR, RFLP, FISH and dot blot are used for its detection. Plate techniques are timeconsuming, PCR bases on enzyme acitivties, thus it can fail due to the presenvce of polyphenols, and hybridization based techniques cannot reach high sensitive. Localized Surface Plasmon Resonance (LSPR) has been used to build a LSPR label-free optical biosensor in connection with gold nanoparticle substrate (Au NPs). The aim of this work was to test several protocols to optimize the best one that may become an important part of the routine analysis using B. bruxellensis like positive control and Saccharomyces cerevisiae as negative control. Buffer, hybridization time and probe concentration were optimized to give high sensitivity.