Volatile fingerprinting and photoacoustic sensing for innovative and no destructive detection of the quarantine plant pathogen Curtobacterium flaccumfaciens pv. flaccumfaciens

Food safety and food security certainly represent some of the greatest global challenges. The accidental or deliberate introduction of a quarantine plant pathogen can cause destructive outbreaks, with a dramatic impact on human health and with heavy socio-economic and political effects. Early identification of quarantine plant pathogens is essential to prevent their entry and spread where they are still absent or with a restricted distribution. Here, innovative and complementary strategies have been developed against the EU quarantine plant pathogen Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), the etiological agent of the bean bacterial wilt and the soybean tan spot. These procedures answer the urgent need of innovative phytodiagnostic methods for the detection of plant pathogens present on asymptomatically vegetable materials and seeds, to overcome the main limits of the current destructive PCR-based methods [1, 2]. Analyses of Volatile Organic Compounds (VOCs) have revealed specific diagnostic traits to specifically detect Cff also into infected seeds. Moreover, for the first time, the potential feasibility of the photoacoustic (PA) approach as a diagnostic method for Cff was here investigated. The PA set-up was successfully developed, and the optical and the non-destructive in vitro Cff detection was successfully demonstrated. The methods here developed for Cff are easily transferable to other quarantine plant pathogens, and contributed to the further development of economic, rapid, and high-efficiency sensors for many other agri-food applications.