Presymptomatic Disease Detection and Nanoparticle-Enhanced Electrical Capacitance Tomography

Here, we present a novel presymptomatic disease detection method by utilizing electrical capacitance tomography (ECT) for plant root monitoring. This was achieved by enhancing the signal with iron oxide nanoparticles (IONPs). IONPs were added to healthy and underdeveloped tomato plants during the course of one and a half months while ECT measurements were collected. The readings for the IONP-exposed samples showed an enhancement over the unexposed samples. This enhancement was greater in the healthy plants when compared with the underdeveloped plants. We also verified earlier claims that ECT can be used for presymptomatic disease detection in bell pepper plants inoculated with Phytophthora capsici (PCap). The healthy plants all showed a continuous increase in capacitance over a 2-week period, while the inoculated plants showed a sudden spike in capacitance 12-24 hours before wilting and browning of the stem occurred. The results from these studies indicate that IONP-enhanced electrical capacitance tomography is a non-destructive, in-situ, and rapid method to monitor relative root health, and that ECT can detect disease presymptomatically.