Here we present a portable microfluidic device that can perform immunoassay for infectious disease diagnosis or detect heavy metal ions in water samples. The device is composed of two major components: nanomaterials modified paper-based detection platform and semi-automated flow manipulator. A reusable 3D-printed device is used to hold a disposable detection pad that modified with functional nanomaterials for water quality monitoring or antibodies for disease diagnosis. Besides, the use of spring-containing 3D-printed syringes manipulates a large-volume sample without manual actuation. Meanwhile, by controlling the flow rate via the linked flow regulator at the syringe outlet, solutions can react stably with the paper platform, which provides detection and pre-concentration effects.