Designing a Novel Paper-based Microfluidic Disc for rapid and Simultaneous Determination of Multiple Nutrient Salts in Water.

In the face of worsening water quality and escalating water environmental emergencies, this study developed a paper-based microfluidic disk for rapid, on-site determination of ammonia nitrogen, nitrates, nitrites, and phosphates in water. The method utilizes centrifugal microfluidics and paper-based technology, simplifying the operation while eliminating the need for on-site reagent preparation. Experimental results demonstrate that the disk requires only 80 microliters of water sample and 2 minutes to complete quantitative analysis of the four nutrients, with a coefficient of variation below 1.72% and spike recoveries ranging from 92% to 113%. The development of the disk provides an effective and rapid on-site testing tool for water quality analysis.