Development of localized surface plasmon resonance biosensors for the detection of Brettanomyces bruxellensis in wine

Abstract : Incident light interacting with noble-metal nanoparticles with smaller sizes than the wavelength of the incident light induces localized surface plasmon resonance (LSPR). In this work a gold nanostructured surface was used for the immobilization of a 5′ end Thiol modified DNA probe to develop a LSPR nanobiosensor for the detection of the spoiler wine yeast Brettanomyces bruxellensis. Gold was evaporated to obtain a gold thickness of 4 nm. DNA (2 μL) from the target microorganism and the negative control at various concentrations were used to test the specificity and sensitivity of the LSPR technique. Changes in the optical properties of the nanoparticles due to DNA-probe binding are reflected in the shift of LSPR extinction maximum (λmax). The results obtained using as target microorganism B. bruxellensis, and as negative control Saccharomyces cerevisiae demonstrated the specificity of both the DNA-probe and the protocol. The LSPR spectrophotometry technique detects 0.1 ng/μL DNA target confirming the possibility to utilize this system for the detection of pathogen microorganisms present in low amount in food and beverage samples.