Smartphone based microfluidic lab-on-chip device for real-time detection, counting and sizing of living algae

A smartphone integrated microfluidic lab-on-chip device was developed for the real-time detection, counting and sizing of living algae in simulated ballast water samples. The device consists of a microfluidic chip, a customer-made fluorescence imaging platform and a smartphone. When living algae pass the laser illumination region of the microfluidic chip, chlorophyll fluorescence is emitted and shown in the smartphone. An algorithm in the smartphone detects, counts and sizes the detected living algae. As a proof of concept, two different sizes of algae were tested and a detection accuracy of larger than 92% was achieved. The sizing accuracy is 94%. The largest moving velocity allowed for detection is determined by the diameter of the algae and the frame per second (fps) of the smartphone. The device is simple in structure and operation and suitable for on-site evaluating the living status of algae in treated ship’s ballast water.