In this work, we developed a new solution for microfluidic zoospore sensing based on the chemotaxis behaviour of zoospores. Phytophthora cactorum zoospores (Figure ) were used as the model Phytophthora zoospore in this work. By creating a gradient of the chemo-attractants, the zoospores were guided to swim actively into the channel. After simulation study and optimisation of the sensing parameters, high-quality signals with high signal-to-noise ratio were successfully recorded when the zoospores passed the electrodes. The whole sensing setup is easy to fabricate and costeffective, thus has great potential to be developed for field studies to detect Phytophthora zoospores in a real-time manner.